|MANAGEMENT, ECONOMY, LAW|
Innovations management, development of R&D effectiveness valuation instruments, innovative projects portfolio optimization is one of the priorities in oil&gas companies. In this context authors have analyzed approaches to economic performance valuation of innovative projects, employed in Rosneft Oil Company PJSC. The currently employed valuation procedure is focused on the calculation of expected net present value (NPV) with valuation of success optionality of the innovation project’s different stages as well as drawing of project’s decision tree, showing key milestones in the management’s decision making process with regard to project’s financing or closure. Optionality allows a more precise project’s NPV valuation, considering risks of each stage fulfillment: research and development stage, engineering stage, including pilot implementation, and final implementation of a technology. Analysis has shown that the current methodology may be enhanced by adding negative results valuation, as well as by including R&D in production costs or increasing R&D costs by coefficient1.5. Application of the methods analyzed in the article will allow improving the quality of the innovative projects valuation and raising the projects’ economic effectiveness to an acceptable level, including projects with negative economic effectiveness at different stages of realization. Innovative projects portfolio becomes more flexible to the external and internal factors, as it includes projects valuated with NPV optionality methodology and includes the whole economic potential of the innovations.
1. Ismagilov A.F., Belkina E.Yu., Khasanov I.Sh., Bortsvadze L.N., A technique of an estimation of innovative projects efficiency in Rosneft NK OAO (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2008, no. 12, pp. 10–13.
2. Belkina E.Yu., Khasanov I.Sh., Polovinkin E.A., The methods of russian oil and gas companies of evaluating the effect of innovative projects (In Russ.), Territoriya Neftegaz, 2011, no. 4.
3. Khasanov M.M., Belkina E.Yu., Zagurenko A.G. et al., Innovation projects valuation using options theory (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 8, pp. 20–22.
4. Krukovskiy A.A., The method of real options in investment management (In Russ.), Trudy ISA RAN, 2008, V. 37, pp. 122-144.
5. Khasanov I.Sh., Dunaev V.F., Belkina E.Yu., Formirovanie sistemy upravleniya nauchno-issledovatel’skimi i opytno-konstruktorskimi rabotami neftegazovoy kompanii (Formation of a control system for research and development in the oil and gas company), Ufa: Mir Pechati Publ., 2015, 208 p.
6. Tsui M., Valuing innovative technology R&D as a real option: application to fuel cell vehicles, Massachusetts Institute of Technology, 2005, 117 p.
7. Budylin M.A., Application of real options for the investment projects valuation (In Russ.), Vestnik SGAU imeni akademika M.F. Reshetneva, 2007, no. 4, pp. 157–160.
8. Kerr W.R., Nanda R., Financing innovation, Harvard Business School, Working paper 15–034, 2014, 24 p.
9. Salerno M.S., Gomes L.A. de V., Brasil V.C., Valuation of innovation projects with high uncertainty: Reasons behind the implementation of real options, International Association for Management of Technology, IAMOT 2015 Conference Proceedings, University of Sao Paulo, pp. 389–403.
10. Vilenskiy P.L., Livshits V.N., Smolyak S.A., Otsenka effektivnosti investitsionnykh proektov: Teoriya i praktika (Evaluation of the effectiveness of investment projects: Theory and practice), Moscow: Delo Publ., 2001, 2002.
11. Kossov V.V., Livshits V.N., Shakhnazarov A.G. et al., Metodicheskie rekomendatsii po otsenke effektivnosti investitsionnykh proektov (Methodical recommendations for evaluating the effectiveness of investment projects), Moscow: Ekonomika Publ., 2000, 421 p.12. Andreev A.F., Dunaev V.F., Zubareva V.D. et al., Osnovy proektnogo analiza v neftyanoy i gazovoy promyshlennosti (Fundamentals of project analysis in the oil and gas industry), Publ. of RF Ministry of Natural Resources, 1997, 341 p.
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Geological exploration on the continental shelf of the Russian Federation is one of the priority trends aimed at replacing hydrocarbon reserves. The exploration activities demand significant capital investments and are associated with high technological, financial, reputational, and environmental risks.
Efficiency of operations of companies involved into geological exploration for hydrocarbons is very much determined by post work analysis of problems and difficulties encountered during the work implementation, understanding of root causes of their occurrence and coming up with proposals to minimize their recurrence in the future. This comprehensive knowledge acquired during the project execution is called the project-specific lessons learned. However, some exploration companies frequently omit keeping records of the lessons learned or the records are kept improperly. RN-Shelf-Arctic LLC and RN-Exploration LLC propose and implement the lessons learned management system related to geological exploration within the license blocks of the continental shelf, helping to solidify the knowledge acquired during the project execution at minimum costs, to analyze a response to the project situations both in the past and in the future.
All the specialists involved in the project take part in a process of the lessons learned. A responsibility matrix is used to specify the responsibility of key participants of the lessons learned process. A Register of learned lessons is prepared based on the work results and a Schedule of lessons learned preparation is used in the annual planning process. Thus, all the activities are carried out taking into account the lessons learned.
Based on results of 2016 activities, the Companies compiled a register, which included more than 200 learned lessons. The experience gained in the previous years of operations had been successfully used in 2017. This way, an internal evaluation rating of the fieldwork supervisors has been prepared, unified terms of reference have been compiled, proposals on streamlining of a procurement process for geophysical activities have been made, requirements towards the ships and equipment have been updated, some corporate procedures have been modified.
1. PMBOK Guide, Newtown Square, Pennsylvania, USA: Project Management Institute, 2013.
2. Aleshin A.V., An'shin V.M., Bagrationi K.A. et al., Upravlenie proektami. Fundamental'nyy kurs (Project management. Fundamental course): edited by An'shin V.M., Il'ina O.N., Moscow: Publ. of HSE, 2013, 500 p.
3. Bashuev S.D. et al., Kreativnye tekhnologii upravleniya proektami i programmami (Creative technologies of project and programm management), Kiev: Sammit-Kniga Publ., 2010, 768 p.
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|GEOLOGY & GEOLOGICAL EXPLORATION|
A case study of an underexplored field is used to consider the issue of building the most probable option of a geological model that takes into account all possible uncertainties and associated geological risks. Since the moment of discovery, the field was categorized as unallocated fund and has been poorly covered by seismic studies, deep drilling, small testing scope; it was understudied by laboratory tests of core and wellhead samples. In 2013, the field was put up for auction with the reserves estimated and approved by the regional commission. After the field was acquired at the auction, an appraisal project was completed in 2015, which increased the estimated gas reserves by approximately 400 bcm in comparison with the reserves approved by the regional commission. The reason for the significant increase is explained by re-processing and re-interpretation of the seismic data, improved amplitude characteristics, taking into account near-surface effects, changes in the structural-tectonic basis of productive reservoirs and their correlation. Both reserves estimates have not been reviewed by the State Commission on Reserves, no 3D geological models have been built.
In view of the total amount of gathered information, the appraisal project looks more preferable than the original estimate, but a significant increase in reserves looks alarming and requires confirmation of the estimated reserves. The key parameters in the probabilistic estimation of reserves are: area, net sand, fluid contact level, flow properties, as well as formation fluids properties.
First, we verified the reliability of structural maps and discovered a number of deviations. Based on the results of the analysis, on the basis of re-processing and re-interpretation of 2D seismic profiles, we found a mathematical method for building an updated structural framework of reservoirs. The tectonic structure data allowed to update tectonic faults in the structural framework, and the fracture amplitudes for each reservoir were determined on the basis of seismic data.
The logging interpretation results were revised and updated on the basis of the author's understanding of the geological structure, the structure of the two reservoirs with updated fluid contacts was detailed, the tectonic faults are generally considered to be non-conductive because of the lack of information on their conductivity. An analysis of the key parameters variability allowed to identify areas of increased risk and made it possible to avoid overstating the resource base. The recommendations for field appraisal, E&A well locations and depths have been given. The resulting data formed the basis for a basic version of the 3D geological model with the most probable volume of reserves and consideration of the existing uncertainties.
1. Structural Analysis. MSc Petroleum Geoscience, London, Royal Holloway University of London, 2000, 503 p.
2. Fokin A., Managing exploration risks & uncertainties, Rogtec, 2011, no. 9, pp. 76–84.
3. Anokhina M.S., Virskiy D.A., Risks and probabilistic assessment of prospective structures resources in southeastern shelf of the Pechora Sea (In Russ.), Nauchno-tekhnicheskiy Vestnik OAO “NK “Rosneft'”, 2015, no. (39), pp. 28–32.
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Oil and gas consumption around the world is constantly increasing. As a result, traditional deposits are depleted and make oil and gas companies pay attention to more complicated facilities. Such objects will include ‘shale oil’, deposits of high-viscosity oil and deposits associated with fractured carbonate reservoirs, one of which is given in this paper. Today, fractured carbonate reservoirs are located on the territory of the Russian Federation in Eastern Siberia, the Caucasus, the Timan-Pechora oil and gas bearing basin, and so on. The object of study in this paper is the Yurubcheno-Tokhomskoye oil and gas condensate field (UTM) located in the Krasnoyarsk Territory. The deposit is unique in its reserves and is characterized by a very complex geological structure. The main deposits of oil and gas fields are confined to the ancient Riphean, carbonate reservoir, which also complicates the study of the reservoir.
In this paper the results of predicting zones with better reservoir properties is described for the Riphean carbonate vuggy-fractured reservoir using a special approach to seismic data processing to of computation scattered component of seismic waves. The paper presents the predicted fractured-vuggy reservoir characteristics (productivity and fracture trends) of a critically important impact on reservoir development. For their prediction, an integrated complex of different-scale geological and geophysical data was applied, including special well logging and testing methods and the results of special seismic data processing.
The approach can be applied to will reduce the uncertainties associated with the geological structure of the deposits of oil and gas, which means that it is more effective to develop the oil and gas fields.
1. Tkachuk D.N., Scientific and technical report “Formirovanie, pererabotka i kompleksnaya interpretatsiya edinogo kuba dannykh MOGT 3D v predelakh Yurubchenskogo LU OAO “Vostsibneftegaz” (Formation, processing and complex interpretation of a single data cube of 3D CDPM within the Yurubchensky license block of Vostsibneftegas JSC), Krasnoyarsk: Publ. of RN-KrasnoyarskNIPIneft’, 2015.
2. Yakupova E.M., Antonenko A.A., Merzlikina A.S. et al., Geological simulation of the carbonate reservoir using of seismic attributes on the example of the Yurubcheno-Tokhomskoye field (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft’”, 2012, no. 4 (29), pp. 4–7.
3. Merzlikina A.S. et al., Prognozirovanie flyuidonasyshchennosti plasta-kollektora na osnove analiza rasseyannoy komponenty (Prediction of reservoir fluid saturation by analyzing the scattered component), Proceedings of EAGE & SPE Joint Workshop “Geoscience Monitoring of the Field Development Process”, Moscow, 4–6 March 2013.
4. Pozdnyakov V.A., Kabanov R.V., Prognosis of rock-fluid system properties of oil-saturated reservoir by seismic data (In Russ.), Geologiya nefti i gaza = The journal Oil and Gas Geology, 2005, no. 2, pp. 21-26.
5. Pozdnyakov V.A., Meretskiy A.A., Merzlikina A.S., Izobrazhenie rasseivayushchikh ob»ektov metodom fokusiruyushchikh preobrazovaniy volnovykh poley (Image of scattering objects by the method of focusing transformations of wave fields), Proceedings of XVIII Gubkin Readings “Innovatsionnoe razvitie neftyanoy i gazovoy promyshlennosti Rossii – nauka i obrazovanie” (Innovative development of the Russian oil and gas industry - science and education), Moscow, 23–25 November 2009 g.
6. Pozdnyakov V.A., Shilikov V.V., Merzlikina A.S. et al., Raschet i interpretatsiya rasseyannykh voln s tsel’yu prognoza fil’tratsionno-emkostnykh svoystv (Calculation and interpretation of scattered waves in order to predict the reservoir porosity and permeability), Proceedings of V International Conference and Exhibition “Saint-Petersburg - 2010”, St. Petersburg, 5 – 8 April 2010 g.
7. Pozdnyakov V.A., Shilikov V.V., Merzlikina A.S., Prognoz kollektorskikh svoystv po rasseyannym volnam (Forecast of reservoir properties by scattered waves), Proceedings of 12th International Scientific and Practical Conference “Geomodel’ – 2010”, Gelendzhik, 13 – 17 September 2010.
8. Pozdnyakov V.A., Shilikov V.V., Merzlikina A.S., Allocation of high fractured zones in carbonate reservoir of Eastern Siberia (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 7, pp. 86–88.
9. Pozdnyakov V.A., Shilikov V.V., Merzlikina A.S., Issledovanie azimutal’noy napravlennosti treshchin po dannym seysmorazvedki volnam (Investigation of the azimuthal orientation of cracks from seismic data), Proceedings of I International scientific-practical conference for geologists and geophysicists “Sochi – 2011”, Sochi, 13–17 May 2011.
10. Pozdnyakov V.A., Merzlikina A.S. et al., Metodika otsenki flyuidonasyshchennosti treshchinnykh rezervuarov na osnove chislennykh metodov trekhmernogo modelirovaniya volnovykh poley (Methods of assessing the fluid saturation of fractured reservoirs based on three-dimensional numerical modeling of wavefields), Proceedings of V International Conference and Exhibition “Saint-Petersburg – 2012”, St. Petersburg, 2–6 April 2012.
11. Gol’din C.V. et al., Seismic imaging in scattered waves as a means of detailing the seismic section (In Russ.), Geofizika = Russian Geophysics, 2004, Special Issue, pp. 23-29.
12. Tuzovskiy A.A., Integral operators for extending fields to two-dimensional inhomogeneous media (In Russ.), Geologiya i geofizika = Russian Geology and Geophysics, 1992, no. 3, pp. 64–72.
13. Tuzovskiy A.A., Shilikov V.V., Merzlikina A.S. et al., Proyavlenie preimushchestvennoy orientatsii mikroneodnorodnostey v azimutal’nom raspredelenii energii rasseyannykh voln (The manifestation of the predominant orientation of the microinhomogeneities in the azimuthal distribution of the energy of scattered waves), Proceedings of 13th International Scientific and Practical Conference “Geomodel’ – 2011”, Gelendzhik, 12–15 September 2011.
14. Merzlikina A.S. et al., Povyshenie informativnosti i razreshennosti volnovykh seysmicheskikh izobrazheniy na osnove polnomasshtabnogo chislennogo modelirovaniya v trekhmerno-neodnorodnykh sredakh s kavernozno-treshchinovato-poristymi rezervuarami primenitel’no k geologicheskim usloviyam Vostochnoy Sibiri (Increase of information content and resolution of wave seismic images on the basis of full-scale numerical modeling in three-dimensional inhomogeneous media with cavernous-fractured-porous reservoirs applied to the geological conditions of Eastern Siberia), Proceedings of International conference “Innovatsionnye seysmicheskie tekhnologii i podschet zapasov uglevodorodnogo syr’ya” (Innovative seismic technologies and calculation of hydrocarbon reserves), Moscow, 15–16 April 2013.15. Chernokalov K.A., Pushkarskiy A.G., Polyarush A.M. et al., Pressure management while drilling systems implementation in carbonate formation with abnormally low reservoir pore pressure (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft’”, 2016, no. 4 (29), pp. 45–48.
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A number of horizontal and extended reach wells is increasing year by year, but meanwhile the quantitative interpretation of logging data is still doubtful. There is no understanding of limits of logging tools and necessity to sel ect the optimal logging suite for the certain geological and technological conditions. This work includes some examples which allowed to make a conclusion about the advantages of the logging during the drilling processes, to evaluate uncertainties appeared in case of application of logging interpretation results of poor quality in geological and flow simulation models. Also, the questions regarding the methodology of logging data interpretation in horizontal wells are discussed as well. The problem with evaluation of properties in case of measurements at small angles of intersection between the axis of horizontal well and reservoir boundaries is highlighted. This led to the apparent smearing of logging curves by the measured depth and apparent changes of reservoir properties. Examples of spatial interpretation of logging data are illustrated as well. This interpretation allows accounting the influence of enclosing rocks and sloping angle, based on the process of direct modelling – comparison – updating. This process provides the restoration of true logging curves and as a result, it is possible to specify the profile of porosity and water saturation, which gives the prerequisite for improving geological and flow simulation models. The advantages of application of the azimuthal measurements RHOB for interpretation of intervals in heterogeneous section – specifying the effective length of the reservoir, porosity of the clean sandstone are shown. The options for accounting the anisotropy by means of direct modelling of logging records (spatial interpretation), results of core studies in two planes (parallel and perpendicular to the layering) and measurements of triaxial induction logging are suggested. Further steps for improving the current techniques of integrated interpretation are considered.
1. Bruce S., Newberry B. et al., Down and out in logging, Middle East Well Evaluation Review, 1991, no. 11, pp. 33–49.
2. Jubralla A.F., Cosgrove P., Whyte S.J., Horizontal highlights, Middle East Well Evaluation Review, 1995, no. 16, pp. 7–25.
3. Allen D., Dennis B., Edwards J. et al., Modelling logs for horizontal well planning and evaluation, Oilfield Review, 1995, Winter, pp. 47–63.
4. Grifths R., Well placement fundamentals, Sugar Land, Texas, 2009, pp. 10.
5. Amer A., Chinellato F., Collins S. et al., Structural steering – A path to productivity, Oilfield Review, 2013, Spring, pp. 14–31.
6. Griffiths R., Morriss C., Ito K. et al., Formation evaluation in high angle and horizontal wells, A new and practical workflow, Proceedings of SPWLA 53rd Annual Logging Symposium, 2012, June16-20, pp. 1–16.
7. Valdisturlo A. et al., Improved petrophysical analysis in horizontal wells: fr om log modeling through formation evaluation to reducing model uncertainty, SPE 164881-MS, 2013.
9. URL: http://logxd.com/
10. Epov M.I., Sukhorukova K.V., Nikitenko M.N. et al., Electromagnetic sounding in deviated and horizontal wells: mathematical modeling and real data interpretation, SPE 162034, 2012.
11. Moran J.H., Gianzero S., Effects of formation anisotropy on resistivity-logging measurements, Geophysics 44, 1979, no. 7, pp. 1266–1286.
12. Shchetinina N.V., Mal’shakov A.V., Basyrov M.A., Zyryanova I.A., Problemy, sostoyanie i perspektivy razvitiya interpretatsii dannykh geofizicheskikh issledovaniy v gorizontal’nykh skvazhinakh Rossiyskoy Federatsii (Problems, condition and prospects for the development of interpretation of horizontal well logging data in the Russian Federation), Proceedings of EAGE scientific seminar “Gorizontal’nye skvazhiny. Problemy i perspektivy” (Horizontal wells. Problems and prospects), Moscow, 2015, pp. 1–13.
13. Shchetinina N.V., Mal’shakov A.V. et al., New approaches and technologies to interpreting logging data in horizontal wells (In Russ.), Nauchno-tekhnicheskiy Vestnik OAO “NK “Rosneft’”, 2016, no. 2, pp. 6–14.
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One of the key points in the geological models building is the determination of the lithology ranges both vertically and laterally during sequential indicator simulation (SIS). For the correct assessment of the variogram ranges it is necessary that the distance between the points of observations was equal or less than the range of variability. At the exploratory stage the distance between the drilled vertical wells is very significant; this condition is fulfilled for observations in the vertical (pitch of observations of 0.2-0.4 m). During the evaluation of the lateral range, when the step of observing the exploration phase is about 2 km or more, the variogram analysis have some difficulty. This article discusses a method of obtaining rough estimates of the value of the lateral range in the low-density drilling field. There are various ways of the horizontal range estimating: using the wells of this field or of the analog field, using seismic slices of 3D survey, description and analysis outcrops for these sediments (literature), formed under similar conditions, multiple realizations. In addition to the above it is proposed to use a statistical method based on the use of statistical relationships between the lateral range value, which characterizes the variability of lithology, and geological characteristics of the studied sediments. To obtain statistical relationships between the lateral range and the geological characteristics of the studied sediments were collected about 150 geological models. In the result, it was found that a statistically significant relationship of the lateral range there is a vertical range and the average reservoir permeability. This allows us to calculate the approximate lateral range required when the lithology SIS builds in conditions when the distance between the observation points (wells) of comparable or greater of range.
1. Deutsch C.V., Geostatistical reservoir modeling, New York: Oxford University Press, 2002, 376 p.
2. Dubrule O., Geostatistics for seismic data integration in earth models, Tulsa: SEG/EAGE, 2003, 279 p.3. Reynolds A.D., Dimensions of paralic sandstone bodies, AAPG Bulletin, 1999, V. 83, no. 2, pp. 211–229.
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RN-Yuganskneftegas LLC is the biggest oil-and-gas production department in Rosneft Oil Company. RN-Yuganskneftegas was found at 1977 and operates 26 oilfields located in Western Siberia. Major part of Yuganskneftegas’ proved oil reserves are concentrated in the Priobskoye and Prirazlomnoye fields and these are green and strategical fields. In 2016 Well Construction Department initiated special project – well cycle reduction (for horizontal wells including wells with multi-stage frac). As a result of worldwide experience and searching of unstandardized decisions to reduce well timing Well construction department found new approach in designing. Our engineers found that extensive field data from wells drilled in the formation demonstrates possibility to optimize some operations by combining production section with horizontal one. The concept was named Dual-casing design. Combined interval should be drilled in one run. Once reaching TD tapered casing string should be run. In consequence of this approach – well timing of horizontal wells is 17 days Vs 30 days (per standard well).
During the pilot project, 12 wells were drilled with a consequent optimization of the solutions as experience gained. The results of the experimental work were recognized as successful and a decision was made to replicate the technology for drilling on different oilfield.
The article describes the features of drilling technology using optimized casing design with results and conclusions.
1. Giniatullin R.R., Kireev V.V., Pilipets E.Yu. et al., Two wells instead of one - reducing the timing of drilling. Difficult - Deeper - Faster (In Russ.), ROGTEC Rossiyskie neftegazovye tekhnologii, 2017, V. 48, pp. 14–22.
2. Gandzhumyan R.A., Kalinin A.G., Nikitin B.A., Inzhenernye raschety pri burenii glubokikh skvazhin (Engineering calculations for deep hole drilling), Moscow: Nedra Publ., 2000, 429 p.
3. Iogansen K.V., Sputnik burovika (Driller satellite), Moscow: Nedra, 1986, 294 p.
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The Yurubcheno-Tokhomskoye oil-gas-condensate field is located in the north of the Krasnoyarsk region and is one of the largest fields in Eastern Siberia. The deposit was discovered in the 1980s, but its development began only in 2009. The operator of the field is East Siberian Oil and Gas Company JSC, which is part of the structure of Rosneft Oil Company.
The oil and gas potential of the Yurubcheno-Tokhomskoye deposit is associated with carbonate and terrigenous deposits of the Vendian and Riphean. The practice of drilling in a fractured reservoir of Riphean deposits using traditional solutions is associated with catastrophic lost circulation of drilling mud reaching several thousand cubic meters. A large volume of losses leads to decrease in the drill-in quality of productive layers, an increase in the construction time and the cost of wells. The use of lost circulation materials (LCM) has shown relative effectiveness due to a wide range of fractures sizes and the difficulty of selecting the optimum LCM composition for such conditions.
In 2016, a set of solutions was implemented in the framework of pilot projects to reduce the intensity of mud losses by controlling the bottomhole pressure (equivalent circulating density (ECD)) while drilling with the use of dynamic pressure management technology (DPM) and nitrogen injection. To achieve the minimum ECD, along with the DPM, it was required to optimize the remaining components of the drilling process, including directional drilling, drilling measurements, bits and drilling fluids. The implementation of this set of solutions has significantly reduced losses of drilling mud (at the first well, the volume of lost drilling fluid was about 500 m3, which is much less the average volume of 2100 m3 in the wells drilled in 2015-2016), to shorten the drilling time for the productive interval and increase initial productivity of wells. During the pilot project, 4 wells were drilled with a consequent optimization of the solutions as experience gained. The results of the experimental work were recognized as successful and a decision was made to replicate the technology for drilling the fractured reservoirs of the Yurubcheno-Tokhomskoye deposit.
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|OIL FIELD DEVELOPMENT & EXPLOITATION|
The widely used semi-log water-oil ratio (WOR) vs recovery semi-log plot is physically sound but should only be applied to a well stock with stable operation conditions. Otherwise the linear relationship between the logarithm of WOR and cumulative oil production can be distorted, often leading to an unacceptably high error margin. However, due to constant and varied wellworks and well activities in the field, meeting the stable operation conditions requirement is often problematic.
This article presents a method of processing the source data for the WOR vs recovery semi-log plot, developed by the author to produce a more linear relationship despite unstable well operation conditions with varying liquid rate changes distorting the actual recovery efficiency curves. In many cases the method is successful, sometimes improving the determination coefficient from 0.450 to 0.982. The method is based on reconstructing the production history of each well assuming a constant liquid rate equal to the last actual value, while retaining the individual cut vs recovery curve for that well. Reconstructing the production history prepares the data for a group of wells for the linear approximation, improving the recoverable reserves estimate accuracy and production forecast reliability. The processing of source data by the proposed method should be complemented with removing certain wells from the selected group: wells, which have been put on production or stopped during the time interval selected for approximation; also wells, which have been worked over during that time interval in a way that allows increasing recoverable reserves.
1. Wolcott D., Applied waterflood field development, Publ. of Schlumberger, 2001, 142 p.
2. Ershaghi I., Omoregie O., A method for extrapolation of cut vs recovery curves, JPT, 1978, February, pp. 203–204.
3. Kambarov G.S., Almamedov D.G., Makhmudova T.Yu., To determine the initial recoverable reserves of the oil field (In Russ.), Azerbaydzhanskoe neftyanoe khozyaystvo, 1974, no. 3, pp. 22–24.4. Pirverdyan A.M., Nikitin P.I., Listengarten L.B., Danelyan M.G., On the issue of the forecast of oil and associated water production in the development of layered heterogeneous reservoirs (In Russ.), Azerbaydzhanskoe neftyanoe khozyaystvo, 1970, no. 11.
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Ice Management System (IMS) is aimed at reduction and prevention of technological, environmental, economic and other risks of ice formations impact at offshore hydrocarbon exploration, production and transportation facilities in the Arctic seas. One of the key elements of IMS is physical impact on icebergs with a vessel in order to change iceberg’s drift path. The "Iceberg Summer 2016" expedition, conducted by OJSC Oil Company Rosneft in cooperation with the Federal State Arctic and Antarctic R&D Institution and specialized "Arctic Research Centre" institution, in the Kara and Barents seas in September and October of 2016, dealt with comprehensive development of the above stated technology, including full-scale experiments of towing of arctic icebergs.
When preparing the expedition, a number of methodologies were addressed, such as assessment of ship suitability to tow icebergs, operating with a single vessel, design of the towing experiments, including the definition of list of parameters to be measured and choice of operation areas.
During the «Iceberg Summer 2016» expedition, accomplished on the "Captain Dranitsyn" icebreaker, 18 iceberg towing experiments were conducted. The experiments were carried out in a wide range of environmental conditions, including wind speed of above 20 m/s, waves of above 4 m, visibility of below 200 m, broken ice and iceberg pieces present in the sea area. The experiments were conducted with objects of various sizes: from ice blocks to an iceberg of weight above 1 million tons. Possibility for maneuvering with an iceberg, to tow a group of small icebergs simultaneously was demonstrated. Corresponding methods have been elaborated. Additionally, the "Kara-Summer-2016" expedition on the research vessel "Academician Tryoshnikov" conducted concurrent studies to match the morphometric parameters of icebergs with parameters of their drift, and to measure environmental variables such as wind, current speed and waving.
Within the processing of the experimental data, hydrodynamic characteristics of an iceberg were compared to results of 3D simulation. The approach for analysis of oscillations in the towing force has also been developed. The performed work resulted in development and verification of original technology for prevention of collisions between a drifting iceberg and offshore engineering facilities for the first time in Arctic.
2. Buzin I.V., Mironov E.U., Sukhikh N.A., Pavlov V.A., Kornishin K.A., Efimov Ya.O., Investigation of drift of the ice features on the Russian Arctic Offshore with the help of automatic radio beacons based on the ARGOS satellite system (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2016, pp. 4–9
3. Wilcox D.C., Turbulence modeling for CFD, DCW Industries, Inc., 1994, 460 p.
4. Devnin S.I., Aerogidromekhanika plokhoobtekaemykh konstruktsiy (Aerohydromechanics of poorly streamlined structures), Leningrad: Sudostroenie Publ., 1983, 320 p.
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|OIL FIELD EQUIPMENT|
Conventional methods of sand control foresee placement of gravel-packed filters in the bottom hole, stabilization of producing formation with chemical compounds, application of erosion – resistant electric submersible pump (ESP) and sucker rod pumping (SRP) units U and installation of filters on their inlets or particles separators. However, all of these methods, in some circumstances fail to resolve completely the problem of submersible equipment protection or ensure extension of mean-time-between failures. Moreover, application of these methods is scarcely may be justified fr om the standpoint of economy. In particular, acute is the problem of setting the mode of wells’ completion after hydraulic fracturing operations to reduce the probability of ESP and SRP units failures. The authors propose to apply the method based on mathematic simulation of potential ingress of particles with pre-determined density and mesh-size in the inlet of submersible pump. The main field of application of the proposed method relates to the wells with low-viscosity fluid’s flow rate below 80 m3/day. The products of such wells contain relatively coarse sand fractions. Considering given conditions, we may reduce the risks of equipment failure upon production process stabilization after completion of well workover by way of setting pump delivery rate below calculated critical flow rate, wh ere the sand of certain coarse grade starts getting to the pump suction. Reduction of pump delivery rate may be attained with the use variable speed controller or temporary operation of equipment in periodic mode. Another area of this method application may include reduced probability of proppant’s suction into the pump upon bringing the wells on to stable production after completion of hydraulic fracturing operations. The method allows planning the parameters of setting operational mode of wells with minimized risk of sand clogging or early wear of submersible equipment, as well as defining the necessity of installation of sand preventers. Commercial application of the proposed method has been already commenced in Rosneft Oil Company.
1. Yakimov S.B., Kosarev I.A., Studying of screen filters efficiency used to protect electric submersible pumps in case of big amount of proppant flowback (In Russ.), Oborudovanie i tekhnologii dlya neftegazovogo kompleksa, 2013, no. 6, pp. 29–32.
2. Yakimov S.B., Pushkarev A.V., Vetokhin E.G., Podkorytov S.M., Some techniques of increasing the time of de-sanders’ effective operation to protect electric centrifugal pumps from sand at Samotlor field (In Russ.), Oborudovanie i tekhnologii dlya neftegazovogo kompleksa, 2015, no. 6, pp. 55–60.
3. Yakimov S.B., Some aspects of choosing technology providing protection of underground equipment from sand with account of dynamics of the sand removal while putting wells into operation at Samotlor oil field (In Russ.), Oborudovanie i tekhnologii dlya neftegazovogo kompleksa, 2013, no. 6, pp. 81–89.
4. Yakimov S.B., Shportko A.A., Sabirov A.A., Bulat A.V., The influence of concentration of abrasive particles in the produced fluid to the reliability of electric centrifugal submersible pumps (In Russ.), Territoriya “NEFTEGAZ”, 2017, no. 6, pp. 50–53.
5. Yakimov S.B., The index of aggressiveness of the rentrained solids at TNK-BP fields in Western Siberia (In Russ.), Neftepromyslovoe delo, 2008, no. 9, pp. 33–38.
6. Ivanovskiy V.N., Sabirov A.A., Bulat A.V. et al., Preliminary results of solids separator pilot testing (In Russ.), Territoriya “NEFTEGAZ”, 2012, no. 11, pp. 88–92.
7. Ivanovskiy V.N., Sabirov A.A., Bulat A.V., Systems of downhole equipment protection from mechanical impurities (In Russ.), Territoriya “NEFTEGAZ”, 2010, no. 9, pp. 62–67.
8. Geologicheskiy slovar' (Geological dictionary): edited by Paffengol'ts K.N., Moscow: Nedra Publ., 1978, 487 p.
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The range of Thermal Manometric Systems (TMS) operated in Rosneft’ Group Entities is quite broad and offered by a considerable number of manufacturers. Every system implemented its own unique data exchange protocol between its underground and on-ground components, which poses relevant limitations in the course of operations justified by the necessity of applying submersible and on-ground blocks of TMS of relevant manufacturer. In practice, upon breakdown of an on-ground block of TMS of certain manufacturer and with zero chance of its substitution (for instance, no warehousing reserve of such on-ground blocks of such manufacturer), an oil producing entity is forced to continue ESP units operation without control over TMS readings, which prevents obtaining and use of on-line information on downhole conditions, which, undoubtedly, triggers the risk of premature failures.
In the framework of the project certain volumes of work were performed for the purpose of development of pilot versatile TMS, and completed pilot production testing of controlled equipment of seven Russian manufacturers. Pilot commercial testing of versatile TMS for ESP units was acknowledged a success.
Ensuring compatibility of TMS supplied to Rosneft, including their control stations, through support of TRANSFER data exchange protocol, provides an opportunity for operation of such equipment in various combinations and without their tying in to specific manufacturer.
The project is of great significance, because at present more than 30 thousand wells of the Company (more than 70%), operated in artificial lifting mode with the use of electrical submersible centrifugal pumps (ESCP), are equipped with submersible telemetric systems (STMS). The Strategy of most of the Company’s Entities is aimed at 100% ESP well stock coverage by STMS.
1. GOST 8.010-2013. State system for ensuring the uniformity of measurements. Procedures of measurements. Main principles.
2. GOST R 8.000-2015. Slate system for ensuring the uniformity of measurements. Basic principles.3. Metodicheskie ukazaniya Kompanii ¹ P1-01.05 M-0005. Edinye tekhnicheskie trebovaniya k UETsN, ShSNU, NKT i drugomu oborudovaniyu dlya dobychi nefti (Common technical requirements for the ESP, SRP, tubing and other equipment for oil production), Moscow, 2016.
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This article discusses a software system INTERMOD for computer clusters. The main functions of INTERMOD are full model decomposition to sectoral models, the initial system initialization models, iterative coupling model, and control the time steps pairing patterns. INTERMOD is not an independent system of hydrodynamic simulator, but uses external simulation as payment modules.
Modern reservoir simulation models of oil and gas fields become more detailed, calculated cells become smaller, and the number of these cells avalanche grows. For large and giant oil fields the number of cells in such models can reach up to 109. Sectoral models always violate the integrity of hydrodynamic modeling objects. This can lead to errors.
The authors have developed and tested computing technology that removes the constraints on the size and detail of reservoir simulation models. This technology is based on the decomposition of large models for sector models and on separate calculations. Algorithm of iterative integration of sector models-Iterative Fitting Boundary Conditions (IFBC) restores the integrity of the full model. This algorithm is more general than option Flux Boundary Conditions (FBC) of reservoir simulators.
IFBC algorithm was tested for several sector models of large oil and gas fields. The field size is 50 * 80 km, 4 objects of development with the gas cap, more than 15000 wells, and 44 years of development, 200 regions selected for modeling. Uniform requirements are defined for all sector models. Sector models built for multiple regions of field. The total number of calculated cells is up to 800 million cells for different implementations of the models. Modeling was done for full model of oil field, for integrated sector models and for non-integrated sector models. Modeling without the integration of sector models leads to errors more than 150 % of the accumulated gas cap gas production (FGPTF, WGPTF) and more than 200 % for accumulated oil wells (WOPT) in comparison with the full model. Using the algorithm IFBC reduces errors before 2–3 %. Computing technology is based on an algorithm IFBC that allows you to create a giant model, "stick together" full of sector models, "implant" sector models in full model. Each of the sector models can be created by individual simulator and can have an independent grid. To 10 compute nodes received acceleration calculations in 7–8 times, to 40 compute nodes and when 90–100 % of their load balancing in 35 times.
The system of INTERMOD can be applied for modeling of large fields; calculation of the heterogeneous sector models as a hydrodynamic system; including sectoral models into other models.
1. Kostyuchenko S.V., Technology of large fields modeling by a system of conjugate sector models Part 2. The method of iterative conjugation of sector models (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 4, pp. 96–100.
2. Kostyuchenko S.V., Tolstolytkin D.V., Chuprov A.A., Shinkarev M.B., Technology of large fields simulation with a system of conjugated sector models. Part 3. The technology approbation by the example of models of Samotlorskoye field AB 1-5 reservoirs (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 8, pp. 78–81.
3. Kostyuchenko S.V., Tolstolytkin D.V., Chuprov A.A., Smirnov A.S., Modeling experience giant oil and gas fields of integrated sectorial models, SPE 171247, 2014.
4. Kostyuchenko S.V., Computing parallel reservoir simulation technology of giant oil and gas fields conjugate systems of sector models (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 10, pp. 68–73.
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The current state of automation of artificial oil lift allows monitoring the operation of downhole equipment in on-line mode on a large well stock from a single monitoring center. This was due to the large-scale introduction of measuring sensors and the development of transmission and storage systems that took place in the last 3-5 years. It turned out that information collected in continuous mode from submersible pressure sensors, which are installed on the intake of the electric centrifugal pump (ESP), can in some cases help with the determination of reservoir parameters: reservoir pressure, permeability, skin factor, and others. Such studies, which do not require special manipulations with the well, were called "passive" or auto wells testing. In this paper, we propose approaches to the development of a "virtual flowmeter" for the purpose of conducting auto well testing. The description of the algorithms that formed the basis of the calculation method for determining the well production rate from indirect data, as well as the results of their testing at various well samples, are described. It is shown that even in the presence of a complete set of initial data, the error in calculating the production rate of the well is about 10% and cannot be significantly reduced because of the errors in the parameter measurements that serve to calculate the production rate.
1. Pashali A.A., Aleksandrov M.A., Kliment'ev A.G. et al., Automatization of collecting and preparation of telemetry data for well testing using ''virtual flowmeter'' (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 11, pp. 60–63.
2. Topol'nikov A.S., Intelligent processing data of virtual telemetric system for interpretation during auto-well testing (In Russ.), Inzhenernaya praktika, 2016, no. 10, pp. 54–59.
3. Anderson D.M. et al., Production data analysis – challenges, pitfalls, diagnostics, SPE 102048, god.
4. Camilleri L.A.P., Banciu T., Ditoiu G., First installation of 5 ESP’s Offshore Romania – A case study and lessons learned, SPE 127593, 2010.
5. Khoroshev E., Zolotarev I., Shevtsov D., Ivanovskiy V., Remote monitoring system – Novomet SmartNet (In Russ.), Arsenal neftedobychi, 2015, no. 1 (18), pp. 15–19.
6. Hasan A.R., Kabir C.S., Two-phase flow in vertical and inclined annuli, International Journal of Multiphase Flow, 1992, no. 18, pp. 279.
7. Brill J.P., Mukherjee H., Multiphase flow in wells, SPE Monograph, Henry L. Dogherty Series, Vol.17, 1999, 164 p.
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|ENVIRONMENTAL & INDUSTRIAL SAFETY|
The paper presents a methodology for auditing and assessing risks in the field of process safety at third-party oil terminals that provide services for the storage, transportation and transshipment of oil and petroleum products for the benefit of Rosneft Oil Company. The methodology establishes a common approach and requirements for the organization and conduct of audits, analysis and assessment of risks in the field of industrial and fire safety, labor protection and environmental safety. So in a technique are presented: frequency and frequency of carrying out of audits; the description of the main stages of the audit; the procedure for interaction between the Company's supervising structural divisions, the structural subdivisions of a third-party oil terminal; assessment and analysis of risks of non-conformities based on a risk-based approach; categorizing terminals based on the results of risk assessment; the process of monitoring the reduction of risks in the field of industrial and fire safety, labor protection and environmental safety, the implementation of corrective actions based on the recommendations of auditors. During the audit, the following activities are performed: verification and analysis of the project, operational and working documentation of the terminal, with the participation of managers and specialists of the responsible structural units of the terminal; inspection of terminal facilities, assessment of the technical condition of production equipment and facilities; verification of the implementation of appropriate organizational and regulatory measures in the field of industrial and fire safety, labor protection and environmental safety at the terminal, compliance with plans and schedules for the implementation of organizational and technical measures. The purpose of the implementation of the methodology is to reduce the risks of accidents at third-party oil terminals, costs and negative impact on the image of Rosneft Oil Company associated with the occurrence of delays in supply or shortage of refined products and petrochemicals to buyers due to incidents and other incidents at these terminals.DOI: 10.24887/0028-2448-2017-11-68-69
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Projections for the world production of I-IV API base oils are submitted in the article. It is noted that base oils of the 1-st group will remain the largest segment of base oil production for a long time. The basic flow schemes for base oil production on the lube oil units of Rosneft Oil Company are described. One of the main processes for producing base oils is solvent dewaxing, which is characterized by high material and capital costs. The main ways of process intensification such as modernization of equipment, applying of deparaffinized additives, the use of and search for new solvents are described in the article.
One of the most promising directions of intensification is the use of high molecular weight ketones, particularly methyl isobutyl ketone (MIBK), which has a number of advantages compared to the traditionally used mixed solvent – methyl ethyl ketone (MEK) and toluene. To confirm the feasibility of replecement of MEK and toluene mixture in MIBK the economic efficiency calculations were carried out. The calculation results have confirmed the economic feasibility of replacement MEK and toluene mixture at MIBK.
1. Rynok bazovykh masel v Rossii i za rubezhom (The market of base oils in Russia and abroad), Moscow: Publ. of Agency of Industrial Information, 2015, 71 p.
2. Van Litszyun', Vliyanie fraktsionnogo sostava maslyanykh distillyatov na pokazateli protsessov proizvodstva neftyanykh masel (Influence of the fractional composition of oil distillates on the parameters of the production processes of petroleum oils), thesis of candidate of technical science, Ufa, 2002.
3. Manovyan A.K., Tekhnologiya pererabotki prirodnykh energonositeley (Technology of processing of natural energy carriers), Moscow: Khimiya, KolosS Publ., 2004, 456 p.
4. Starkova N.N., Shuverov V.M., Ryabov V.G. et al., Increasing the efficiency of dewaxing in the deoiling stage (In Russ.), Khimiya i tekhnologiya topliv i masel = Chemistry and Technology of Fuels and Oils, 2003, no. 6, pp. 14–15.
5. Yakovlev S.P., Radchenko E.D., Blokhinov V.F., Efficiency of dewaxing lube oil raffinate in different types of crystallizers (In Russ.), Khimiya i tekhnologiya topliv i masel = Chemistry and Technology of Fuels and Oils, 2002, no. 2, pp. 16–17.
6. Yakovlev S.P., Zakharov V.A., Boldinov V.A., Esipko E.A., Combined process for production of base oils and exhaustively deoiled waxes. use of oscillating crystallizers (In Russ.), Khimiya i tekhnologiya topliv i masel = Chemistry and Technology of Fuels and Oils, 2006, no. 2, pp. 13–15.
7. Zolotarev P.A., Nigmatullin R.G., Effectiveness of soaking sections in process of dewaxing lube raffinates (In Russ.), Khimiya i tekhnologiya topliv i masel = Chemistry and Technology of Fuels and Oils, 1997, no. 4, p. 26.
8. Patent no. 103789039 CNA, Solvent by dewaxing method, Inventors: Wang Shixin, Yuan pingfei, Wang Yongfang.
9. Patent no. 4622130 US, Economic combinative solvent and catalytic dewaxing process employing methylisopropyl ketone as the solvent and a silicate-based catalyst, Inventor: Stem S.C.
10. Patent no. 1499533 GBA, Dewaxing waxy petroleum oil stocks.
11. Informatsionno-analiticheskiy otchet v oblasti eksportno-importnykh operatsiy rossiyskikh predpriyatiy (Information and analysis report in the field of export-import operations of Russian companies), Moscow: Biznes-Aktiv Publ., 2016, 135 p.
12. Kulakova T.N., Metodicheskie ukazaniya k kursovomu i diplomnomu proektirovaniyu “Ekonomicheskoe obosnovanie diplomnykh proektov” (Methodical instructions for course and diploma projecting "Economic justification of diploma projects"), Samara: Publ. of SSTU, 2004, 66 p.
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|OIL & GAS COMPANIES|
|GEOLOGY & GEOLOGICAL EXPLORATION|
The Severo-Varyoganskoye oil and gas condensate field is located on the territory of the Nizhnevartovsk region of the Khanty-Mansiysk Autonomous District. The results of well drilling in the Severo-Varyoganskoye field prove high potential for hydrocarbon production in the upper part of the Pre-Jurassic sequence (Devonian-Carboniferous), but, on the other hand, indicate extremely complex geological architecture of the target, which considerably impairs the effectiveness of seismic predictions. Structural and compositional characteristics of rocks by core, well section layering and correlation allow suggesting of an optional stratification for the upper section of the Pre-Jurassic sequence. The section with the core is divided into six strata of different lithologic composition. Now there are two most common points of view on the mechanism of formation of promising deposits of the Devonian-Carboniferous: a) weathering crust and, b) hydrothermal-metasomatic formations. Silicites and argillaceo-siliceous rocks were interpreted by the authors as primarily sedimentary, mainly of biogenic (planktonic) type, rarely mixed bio-chemogenic type. Mutual arrangement, close age and rock composition, common genesis features allow the West-Siberian silicites to be considered as the age and facial analogue of Domanic shales of the Russian platform. On the other hand, unlike the Russian platform Domanic, the West-Siberian platform “Domanic” was subjected to intensive hydrothermal – metasomatic impact as a result of activated volcanic processes, which could have probably resulted in organic matter decomposition and acid re-working of rocks.
1. Orlov A.A., Antonishin G.I., Ivaniv M.N., New data on the structure and petroleum potential of the Paleozoic deposits of the Middle Ob region (In Russ.), Izvestiya vuzov. Neft' i gaz, 1988, no. 4, pp. 3–5.
2. Arkhipov S.V., Borkun F.Ya., Pitkevich V.T. et al., Collectors of pre-Jurassic-Jurassic complex of North Varioganskaya Square (In Russ.), Geologiya nefti i gaza, 1989, no. 5, pp. 27–29.
3. Bochkarev V.S., Grishchenko A.I., Leshchenko V.E. et al., Paleozoic deposits – a new direction of exploration for oil and gas in the south-east of Western Siberia (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 1996, no. 1, pp. 2–8.
4. Shut'ko S.Yu., Kir'yanova N.I., New data on the contact zone of the platform cover and Paleozoic formations of the North Varioganskoye and Varioganskoye fields (In Russ.), Geologiya nefti i gaza, 1989, no. 11, pp. 14–16.
5. Makov A.I., Taldykin V.A., Zakonomernosti razmeshcheniya zalezhey nefti i gaza v fundamente Zapadno-Sibirskoy plity na territorii KhMAO (Regularities in the location of oil and gas deposits in the basement of the West Siberian Plate in KhMAO), Proceedings of scientific and practical conference “Puti realizatsii neftegazovogo potentsiala KhMAO” (Ways of realization of oil and gas potential of KhMAO), Khanty-Mansiysk, 2003, Part 1, pp. 94–101.
6. Kirda N.P., Paromov I.V., Smirnova V.V. et al., Geologicheskoe razvitie i stroenie doyurskikh kompleksov tsentral'nykh i vostochnykh rayonov KhMAO, perspektivnye napravleniya poiskovo-otsenochnykh rabot na neft' i gaz (Geological development and structure of the pre-Jurassic complexes of the central and eastern regions of the Khanty-Mansiysk Autonomous Okrug, promising directions of prospecting and appraisal work for oil and gas), Collected papers “Perspektivy neftegazonosnosti paleozoyskikh otlozheniy na territorii Khanty-Mansiyskogo avtonomnogo okruga” (Oil and gas potential of Paleozoic deposits in the Khanty-Mansiysk Autonomous Okrug), Proceedings of Scientific and Practical Conference, 12 February, 2003, pp. 1–18.
7. Zubkov M.Yu., Fedorova T.A., Hydrothermal secondary collectors in black shale (In Russ.), Geologiya nefti i gaza, 1989, no. 6, pp. 26–30.
8. Zubkov M.Yu., Gidrotermal'nye selitsity – perspektivnyy neftegazopoiskovyy ob"ekt doyurskogo fundamenta Zapadno-Sibirskoy plity (Hydrothermal Selitsites - a promising oil and gas prospect of the pre-Jurassic basement of the West Siberian Plate), Collected papers “Geologiya i neftegazonosnost' nizhnikh gorizontov chekhla Zapadno-Sibirskoy plity” (Geology and oil and gas content of the lower horizons of the cover of the West Siberian plate), Novosibirsk: Publ. of SNIIGGiMS, 1990, pp. 87–101.
9. Neruchev S.G., Uran i zhizn' v istorii Zemli (Uranus and life in the history of the Earth), St. Petersburg: Publ. of VNIGRI, 2007, 328 p.
10. Yudovich Ya.E., Ketris M.P., Geokhimiya chernykh slantsev (Geochemistry of black shale), Leningrad: Nauka Publ., 1988, 282 p.
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In the article, in addition to the existing scientific studies, the prospects of the oil and gas content of Paleogene clayey rocks of the Eastern Ciscaucasia are examined on the basis of a detailed study of the neotectonic development of the studied region. The main tectonic elements affecting the geodynamics of the entire Caucasus are the two large lithospheric plates - the Scythian and Arabian. As a result of the interaction of these plates, the North Caucasus region tectonically represents a zone of collision, characterized by a stretching in the sublatitudinal direction, compression deformation in the submeridional direction, and a general uplift with the mountain system of the Greater Caucasus.
The degree of geodynamic activity of the territory under consideration was estimated from the velocity maps of modern vertical and horizontal movements, according to which the Eastern Ciscaucasia as a whole is subjected to intensive geotectonic processes, and in particular, experiences uneven ascent, which contributes to the formation of cracks and their opening. Due to the interaction of lithospheric plates accompanied by earthquakes, as is known, disruptive disturbances that affect the capacitive-filtration properties of rocks are formed. The paper analyzes the data on the strongest earthquakes within the study area. The authors built a map of the trend of movement of the foundation blocks. On the basis of which it turned out that the Stavropol arch and the Prikum system of uplifts rendered the greatest influence on the territory under consideration, as well as the depression region of the Tersko-Caspian advanced trough. The Nogai step and the Mineralovodsky protrusion move upward, without affecting the neighboring blocks. Depressions of the Manychy troughs zone drag only one adjacent block downward. The movement of all other blocks is subordinate. Thus, on the basis of the constructions, zones stretching and compression zones are identified.
Geological and geochemical studies were carried out to assess the oil and gas potential of the study area. Based on the data of pyrolytic (in the Rock-Eval modification) and chemical-bituminological analysis methods, clayey rocks of the Paleogene (Khadum, Kumsko-Keresinsky formation) belong to oil and gas bearing strata with a high oil and gas generation potential.
On the basis of neotectonic and geological-geochemical criteria, the paper proposes a scheme for the prospects of oil and gas potential of Paleogene clay rocks of the region under study. Thus, in the studied territory, Paleogene sediments have all the prerequisites for the industrial development of hydrocarbon accumulations. The main attention, from the position of neotectonics, deserves the zone of the greatest geodynamic activity: zones of epicenters of earthquakes, zones of faults or faults, zones of opening of cracks in hills foundation.
1. Gabnasyrov A.V., Lyadova N.A., Putilov I.S. et al., Evaluation of Doman’ formation unconventional resources in LUKOIL PJS (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 8, pp. 78–83.
2. Koronovskiy N.V., Demina L.I., Collision stage of the evolution of the Caucasian sector of the Alpine foldbelt: Geodynamics and magmatism (In Russ.), Geotektonika = Geotectonics, 1999, no. 2, pp. 17–34.
3. Milyukov V.K., Mironov A.P., Rogozhin E.A. et al., Velocities of contemporary movements of the Northern Caucasus estimated from GPS observations (In Russ.), Geotektonika = Geotectonics, 2015, no. 3, pp. 56–65.
4. Ulomov V.I., Danilova T.I., Medvedeva N.S. et al., Assessment of seismic hazard in the North Caucasus (In Russ.), Fizika Zemli = Izvestiya. Physics of the Solid Earth, 2007, no. 7, pp. 31–45.
5. Rogozhin E.A., Gorbatikov A.V., Zaalishvili V.B. et al., New data on the deep structure, tectonics, and geodynamics of the Greater Caucasus (In Russ.), Doklady Akademii nauk = Doklady Earth Sciences, 2015, V. 462, no. 3, pp. 356–359.
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At present, the coefficient of porosity is traditionally determined by the method of Preobrazhensky and by the results of a petrophysical interpretation of well log data. However, there are many examples of the significant error in its determination, which ultimately affects the determination of their filter-capacitance properties, the recovery rate of oil and extracted reserves. In this paper, the porosity coefficients are compared by traditional and precision methods for oil-containing terrigenous reservoirs of the Paschian (Upper Devonian), and Tula and Bobrikovskian (Lower Carboniferous) horizons, as well as carbonate reservoirs of the Tournaisian stage, using the example of one of the deposits in the central part of the Volga-Ural oil and gas province. It is shown that precision methods make it possible to study in more detail the internal pore space of oil-containing reservoirs. X-ray computer microtomography showed the uneven and multidimensional porosity of Devonian sandstones, due to their micro-lamination. The most accurate values of the porosity coefficient from the results of microtomography were obtained for cubes of the smallest size (with linear dimensions of the sample less than 5 mm), so they correspond to a higher resolution of the survey, which allows detecting smaller pores. In this connection, the inverse dependence of the porosity coefficient on the size of the samples was established. Variability of porosity along the layers in the lateral direction is revealed (the property of ‘microfaciality’). The combination of traditional and precision methods for determining porosity coefficients will allow us to calculate the oil recovery factor on explored and developed oil deposits more correctly, because additional information on pore size and cavity, connectivity and type of channels, as well as microfacies are taken into account.
1. Zakirov S.N., Indrupskiy I.M., Zakirov E.S., Anikeev D.P., Unimplemented reserves in oil and gas subsoil use of Russia (In Russ.), Georesursy = Georesources, 2015, no. 1, pp. 33–38.
2. Zakirov S.N., Zakirov E.S., Indrupskiy I.M., About regulatory documents in petroleum subsurface management (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 10, pp. 6–9.
3. Zakirov T.R., Galeev A.A., Konovalov A.A., Statsenko E.O., Analysis of the ''representative elementary volume'' sandstones reservoir properties using the method of X-ray computed tomography in Ashalchinskoye oil field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 10, pp. 54–57.
4. Zakirov T.R., Galeev A.A., Korolev E.A., Statsenko E.O., Investigation of the porosity and absolute permeability coefficients of carbonate reservoir using the X-ray computed microtomography (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 6, pp. 56–59.
5. Kadyrov R.I., Zakirov T.R., 2D fractal and multifractal analysis of porous space in carbonate oil reservoir (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 11, pp. 72–74.
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The work is devoted to the search and application of a new approach to modeling Achimov horizon, in order to clarify the geological structure of this horizon. Materials on the Achimov horizon were analyzed and the geological structure of the Tarasovskoye deposit was studied, including its stratigraphy, tectonics and oil and gas content. An analysis of field-geological materials showed the existence of a number of problems associated with the underdevelopment of productive Achimov deposits by drilling and seismic exploration. Such problems include, first of all, the absence of reliable correlation of the clinoform deposits, the absence of dismemberment of the clinocyclites, the uncertainty of the connectedness of sand bodies and their field circuits. All this served as the reason for the search for non-traditional approaches for solving some of the above-mentioned problems, in particular, greater involvement of field-geophysical data and application of the J-function. We approved geological model of Achimov deposits thickness and picture of deposits and traps formation. Analysis of data of a well logging complex result in lithologic differentiation, the porosity coefficient and permeability coefficient were calculated. With the help of several calculations in the Primary program, the oil saturation coefficient was calculated from J-functions on the basis of well logging data. A correlation scheme with clinocyclites Àch01, Àch02, Àch11 was constructed. An analysis of the correlation results, during which a cyclic structure was noted, made it possible to single out the expected boundaries of the clinocyclites: Àch01, Àch02, Àch11, which are the most promising from the oil-bearing point of view. Analyzing the correlation schemes obtained during the calculation of the oil saturation coefficient for the J-function and the in-layer correlation, we conclude that the boundaries of the clinocyclites completely coincide, and thus the proposed technique makes it possible to isolate the boundaries of the clinocyclites.
Based on the data obtained a new geological model was constructed, which is an interlayering of the clinoform beds that are cyclically extended to the west.
1. Fomenko V.G., Opredelenie po dannym GIS podschetnykh parametrov i prognozirovanie produktivnosti kollektorov perekhodnykh zon (na primere mestorozhdeniy Zapadnoy Sibiri i Orenburzh'ya) (Determination of volumetric parameters using well logging data and forecasting the productivity of collectors of transition zones (on the example of deposits in Western Siberia and Orenburg region)): thesis of doctor of geological and mineralogical science, Tver', 1993.
2. Tiab D., Donaldson E.C., Theory and practice of measuring reservoir rock and fluid transport properties, Gulf Professional Publishing, 2004, 880 p.
3. Darling T., Well logging and formation evaluation, Gulf Professional Publishing, 2005, 336 p.
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The article shows the possibility of solving an underdetermined system of petrophysical equations for carbonate reservoirs of polymineral composition containing calcite, dolomite, anhydrite, quartz and clay minerals characterized by a complex structure of the void space (a combination of intergranular pores, fractures and caverns), imposing restrictions on the proportions of mineral components and the coefficient of porosity. The solution of the system of petrophysical equations is calculated numerically by minimizing the value of the discrepancy function between the synthetic curves and well logging, measured in the borehole. The reliability of the solution of the system is studied with the exception of one or several methods and the corresponding petrophysical equations. It is shown that excluding from the system of petrophysical equations the parameters of a single geophysical method - density gamma gamma logging - leads to a slight loss of accuracy. When calculating porosity, the minimum complex of geophysical methods should consist of acoustic, neutron and natural gamma-activity method. The calculated values of the porosity coefficient are correlated with core determinations. The discrepancy between the computed values of the porosity coefficient from the geophysical survey data and the values of the porosity coefficient for the core is ±3%. An adaptation of the system of petrophysical equations for the complex structure of the pore space of carbonates is proposed. In the intervals of the section with secondary porosity, the system of petrophysical equations varies in accordance with the behavior of the acoustic wave. Using the results of logging on longitudinal waves, calculations were made of the cavernous and fractured constituents of the void space of carbonate rocks. It is obtained that the coefficient of fractured porosity of carbonate rocks varies from 0.01 to 1%. Coefficient of caverns porosity reaches 10%. The values calculated for the geophysical data of the coefficient of caverns porosity fit into the range of values determined on large core samples.
1. Knyazev A.R., Nekrasov A.N., The technology of estimation of porosity, cavern porosity and open fissility of the complex-constructed carbonate rocks (In Russ.), Geofizika, 2011, no. 5, pp. 81–88.
2. Popova N.S., Nekrasov A.S., The algorithm elaboration for definition of porosity and lithologic composition of sulphate-carbonate reservoir rocks by geophysical data (In Russ.), Geofizika, 2011, no. 5, pp. 89–92.
3. Metodicheskie rekomendatsii po podschetu zapasov nefti i gaza ob’emnym metodom. Otsenka kharaktera nasyshchennosti po dannym GIS (Guidelines for the calculation of reserves of oil and gas by volumetric method. Assessment of the nature of saturation according to well logging): edited by Petersil’e V.I., Poroskun V.I., Yatsenko G.G., Moscow –Tver: Publ. of VNIGNI, 2003. 261 p.
4. Taha H.A., Operations research: An introduction, Prentice Hall, 2006, 838 p.
5. Wagner H.M., Principles of operations research: with applications to managerial decisions, Prentice-Hall, N.J., 1975, 488 p.6. Yumatov A.Yu., Rasprostranenie uprugikh prodol'nykh voln v poristykh gornykh porodakh s treshchinami i kavernami (Propagation of elastic longitudinal waves in porous rocks with cracks and caverns): thesis of candidate of physical and mathematical science, Moscow, 1984, 131 p.
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Today, practically all oil-producing companies have faced inefficiency of traditional technologies of research and development of reservoir. In the late development, when maintaining the level of oil and gas production is a strategic task, solving the problems of searching for missed intervals, classifying reservoirs for quality, ranking the zones for drilling new production wells becomes more urgent.
In the last decade, new instruments have been developed to study the properties of rocks and reservoir fluids in wells or in laboratory conditions. Methodological and metrological support of modern equipment allows supplementing the geological view of deposits, but a number of wells where new technologies are used usually do not exceed 10%, and often is only 3-5%.
Since the share of the main well stock with the basic log data is more than 90%, a very important issue of improving the quality of the study is an increase in the informativeness of petrophysical support.
The variety of results of core research provides the development of new technologies at the junction of different disciplines. In this paper, the principle of petrophysical modeling of reservoir properties is considered, taking into account the facies features of the formation of oil and gas bearing deposits.
1. Dobrynin V.M., Vendel’shteyn B.Yu., Kozhevnikov D.A., Petrofizika (Fizika gornykh porod) (Petrophysics (Physics of rocks)): edited by Kozhevnikov D.A., Moscow: Neft’ I gaz Publ., 2004, 368 p.
2. Tiab D., Donaldson E.C., Theory and practice of measuring reservoir rock and fluid transport properties, Gulf Professional Publishing, 2004, 880 p.
3. Khanin A.A., Porody-kollektory nefti i gaza neftegazonosnykh provintsiy SSSR (Reservoir rocks of oil and gas of the USSR petroliferous provinces), Moscow: Nedra Publ., 1973, 303 p.
4. Reading H.G., Sedimentary environments: processes, facies and stratigraphy, Blackwell Publishing Limited, Second edition, 1986.
5. Belyakov E.O., Mukhidinov Sh.V., Ispol'zovanie obobshchennykh zavisimostey dlya postroeniya petrofizicheskikh modeley fil'tratsionno-emkostnykh svoystv s otsenkoy granichnykh parametrov vydeleniya kollektorov i opredeleniya ikh kharaktera nasyshchennosti (Using the generalized relationships for constructing petrophysical models of reservoir properties estimation of reservoir boundary parameters and determine their nature saturation), Collected papers “Petrofizika slozhnykh kollektorov: problemy i perspektivy” (Petrophysics of complex reservoirs: problems and prospects), Moscow: Publ. of EAGE Geomodel', 2015, 383 p.6. Belyakov E.O., Frantsuzov S.E., Mukhidinov Sh.V. et al., Probabilistic model of the distribution of rocks pore space fluid saturation as a base of specification of petrophysical models of reservoir properties (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 12, pp. 48-50.
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Low-viscosity carboxymethyl cellulose (CMC) and low-viscosity polyanionic cellulose (PAC) are commonly added to modern drilling mud compositions as fluid loss reducing agents. Currently, starch-based reagents are not widely used due to their high biodegradation (áèîäåãðàäèè) and low heat resistance. However, when carboxymethyl is added to starch, its bacterial and thermal resistance increases. Therefore, taking into consideration the fact that the cost of carboxymethyl starches (CMC) is 30-50% lower than and low-viscosity polyanionic cellulose (PAC), the most crucial goal of the research is to understand if it is possible to substitute PAC for CMC in some types of the drilling muds. However, in our research is it shown that in order to get some comparable properties of the various systems of the drilling muds, it is necessary to keep the content of the active and inert solid phases at a certain level. It is not possible to adequately substitute PAC for CMC when solid phase is in the low content. However, it is common knowledge that the content of the active and inert solid phase in the drilling mud composition is higher than it is minimally required in order to obtain equal properties when CMC is used instead of PAC. Also, the production-scale CMC, which degree of substitution in carboxymethyl is about 30, does not have sufficient thermo- and salt resistance. Moreover, they are subjected to the quick biodegradation in the fresh system (ïðåñíàÿ ñèñòåìà). That is why the samples of reagents with the degree substitution more than 60 were synthesized. The properties of CMC when it is used as fluid loss reducing agent have comparable filtration drilling mud properties to the mud compositions under study, therefore, they can be recommended to be used in the drilling muds instead of PAC.
1. Belenko E.V., Research into biodestruction processes of polysaccharide agents (In Russ.), Zashchita okruzhayushchey sredy v neftegazovom komplekse, 2007, no. 8, pp. 32–36.
2. Rogovin Z.A., Khimiya tsellyulozy (Chemistry of cellulose), Moscow: Khimiya Publ., 1972, 520 p.
3. Caenn R., Darley H.C.H., Gray G.R., Composition and properties of drilling and completion fluids, Gulf Professional Publishing, 2016, 748 r.
4. Koshelev V.N., Nauchnye i metodicheskie osnovy razrabotki i realizatsii tekhnologii kachestvennogo vskrytiya produktivnykh plastov v razlichnykh geologo-tekhnicheskikh usloviyakh (Scientific and methodological foundations for the development and implementation of technology for the qualitative drilling-in in various geological and technical conditions): thesis of candidate of technical science, Krasnodar, 2004.
5. Anisimov A.V., Lodina I.V., Comparison of the properties of starch reagents in a system of mineralized drilling mud (In Russ.), Neft'. Gaz. Novatsii, 2014, no. 9, pp. 43–47.
6. Navard P., The European polysaccharide network of excellence (EPNOE), Springer-Verlag, 2012, 407 p.
7. Richardson S., Gorton L., Characterization of the substituent distribution in starch and cellulose derivatives, Analytica Chimica Acta, 2003, V. 497, pp. 27–65.
8. Sagitov R.R., Minaev K.M., Zakharov A.S., Sravnitel'noe issledovanie ponizitelya fil'tratsii na osnove karboksimetilirovannogo krakhmala i tsellyulozy (A comparative study of a filtering agent based on carboxymethylated starch and cellulose), Collected papers “Burenie v oslozhnennykh usloviyakh” (Drilling in complicated conditions), Proceedings of International Scientific and Practical Conference, St. Petersburg: LEMA Publ., 2016, pp. 90–94.
9. BeMiller R., Whistler starch: Chemistry and technology, Elsevier, 2002, 900 p.
10. Shirokov V.A., Issledovanie i razrabotka modifikatsii polisakharidnykh reagentov dlya povysheniya kachestva promyvochnykh zhidkostey pri stroitel'stve neftyanykh i gazovykh skvazhin (Research and development of modification of polysaccharide reagents to improve the quality of drilling fluid for oil and gas wells): thesis of candidate of technical science, Krasnodar, 2010.11. Minaev K.M., Martynova D.O., Zakharov A.S. et al., Synthesis of Carboxymethyl Starch for increasing drilling mud quality in drilling oil and gas wells, IOP Conf. Ser. Earth Environ, 2016, V. 43, pp. 1–7.
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|OIL FIELD DEVELOPMENT & EXPLOITATION|
The amount of hydrocarbons that remains in the oil reservoir at the final depletion phase of field production largely depends on the efficiency of the technologies and recovery techniques implemented during field development. Despite modern advances in Enhanced oil recovery techniques, it is estimated that about 30 to 70% of oil, on average, remains in the reservoir worldwide at the end of production. The structural and chemical nature of residual oil varies widely. In some reservoirs only a fraction of it is mobile. Studies showed that residual oil immobility is not that as much governed by the in situ pressure gradients (i.e. the influence of the hydrodynamic and capillary forces) or pore-throats restrictions, as by the differences in the chemical composition and density of the immobile and mobile oil. This article briefly discusses methods of determining immobile residual oil saturation in carbonate cores and its effects on fluid flow in the reservoir and field production prediction results.
The methods generally used for determining the residual oil saturation of a reservoir are very many, among which are both direct (on core samples) and indirect (well-log analyses). Direct methods generally imply carrying out tests on fresh cores extracted with clay mud from wash-out zones of the reservoir. This article futher describes a laboratory method for determining the immobile residual oil saturation on fresh core samples by alternating core-cleaning methods. A combination of mild and harsh cleaning methods were used to determine reservoir immobile residual oil saturation and several tests were carried out on carbonate cores to study its effects on basic reservoir properties and flow characteristics.
The results obtained from both laboratory flow tests and the hydrodynamic modeling of a carbonate reservoir show that the presence of immobile oil has a significant influence, not only on the nature of fluid flow in the reservoir, but also on field production prediction results.
1. Mikhaylov N.N., Ostatochnoe neftenasyshchenie razrabatyvaemykh plastov (Residual oil saturation of developed reservoirs), Moscow: Nedra Publ., 1992, 240 p.
2. Dzhemesyuk A.V., Mikhaylov N.N., On the distribution of capillary-clamped residual oil in the reservoir (In Russ.), Izvestiya vuzov. Neft' i Gaz, 1990, no. 2, pp. 14–18.
3. Dmitrievskiy A.N., Kol'chitskaya T.N., Mikhaylov N.N. et al., Analiz struktury i podvizhnosti ostatochnykh zapasov na obvodnennykh ploshchadyakh Talinskogo mestorozhdeniya (Analysis of the structure and mobility of residual reserves in the watered areas of the Talinskoe deposit), Moscow, 2001, 152 p.
4. Drozdov V.A., Dvorak S.V., Il'in V.M., Sonich V.P., Residual oil saturation of the reservoirs of the Noyabrsky district (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 1991, no. 4, pp. 19–21.
5. Mikhaylov N.N., Dzhemesyuk A.V., Kol'chitskaya T.N., Semenova N.A., Izuchenie ostatochnogo neftenasyshcheniya razrabatyvaemykh plastov (The study of residual oil saturation of developed reservoirs), Moscow: Publ. of VNIIOENG, 1990, 60 p.
6. Kotyakhov F.I., Fizika neftyanykh i gazovykh kollektorov (Physics of oil and gas reservoirs), Moscow: Nedra Publ., 1987, 270 p.
7. Bykov N.E., Maksimov M.I., Fursov A.Ya., Spravochnik po neftepromyslovoy geologii (Reference book on oilfield geology), Moscow: Nedra Publ., 1981, 525 p.
8. Koshlyak V.A. Sultanov T.A., Izuchenie nefteotdachi plastov metodami promyslovoy geofiziki (Study of oil recovery by methods of field geophysics), Moscow: Nedra Publ., 1986, 193 p.
9. Lenchenkova L.E., Kabirov M.M, Persiyantsev M.N., Povyshenie nefteotdachi neodnorodnykh plastov (Enhanced oil recovery of heterogeneous layers), Ufa: Publ. of USPTU, 1998, 255 p.
10. Gabsiya B.K., Nikitina I.N., Distinctive features of hydrocarbon phase modeling in flow experiments (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 2, pp. 44–46.11. Kovalev K., Grishin P., Kurochkin A. et al., Aged carbonate cores wettability verification, SPE 182064-RU.
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Hydraulic fracturing is one of major methods of wellbore completion during tight oil field development. Resulting fracture permeability may significantly decline in time for some reasons. The wellbore productivity decreases as a result. One of major ways to restore the permeability of fracture is repeated hydraulic fracturing. This operation under definitive conditions may result not in expected fracture permeable properties renewal but in second hydraulic fracture initiation. The second hydraulic fracture as a rule lies in nearly perpendicular direction with respect to the first one. The physical fundamentals of fracture reorientation of second hydraulic fracturing operation are described in this paper. This phenomenon arises only on working production wells completed with fracture fixed by proppant. The reorientation phenomenon allows using fundamentally new way to find wells – candidates for the second hydraulic fracturing operation. The essential advantage of using this new way is in involvement of resources from higher residual content of hydrocarbons and also in a lack of new wellbore drilling necessity. The major risk in using the effect of fracture reorientation is in the possible breakthrough of the water injection front and related increasing of oil production watering. Using the phenomenon described is possible only by using geomechanical instruments of formation stress-strain state monitoring. In the paper we also show some examples of wells with reoriented fractures. The confirmation of the effect was given both using direct measurement with cross-dipole acoustic logging and indirect way using watering change analysis of oil production during a long-time.
1. Roussel P.R., Sharma M.M., Quantifying transient effects in altered-stress refracturing of vertical wells, SPE 119522, 2009.
2. Fedorov A.I., Davletova A.R., Kolonskikh A.V., Toropov K.V., Justification of the necessity to consider the effects of changes in the formation stress state in the low permeability reservoirs development (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2013, no. 2, pp. 25–29.
3. Latypov I.D., Fedorov A.I., Nikitin A.N., Research of reorientation refracturing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 10, pp. 74–78.
4. Elbel J.L., Mack M.G., Refracturing: Observations and theories, SPE 25464, 1993.
5. Li P., Song Z., Study on reorientation mechanism of refracturing in Ordos Basin, SPE 104260, 2006.
6. Economides M.J., Nolte K.G., Reservoir stimulation, Third edition, Wiley, NY and Chichester, 2000, 750 p.
7. Liu H. et al., Evaluation of refracture reorientation in both laboratory and field scales, SPE 112445, 2008.8. Fedorov A.I., Davletova A.R., Reservoir stress state simulator for determining of fracture growth direction (In Russ.), Geofizicheskie issledovaniya, 2014, V. 15, no. 1, pp. 15–26.
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The current publication represents the fundamentally new approach to selection of well candidates for refracturing that is suggested based on the stress-deformed reservoir state monitoring using the geomechanical modelling tools and downhole investigations. On the example of RN-Uganskneftegas LLC the statistical analysis of well-candidates base for refracturing is implemented. The necessity for developing of innovational methods for the increase of well stimulation works is demonstrated. As a result the method of well-candidates search for refracturing is suggested where the effect of spatial fracture reorientation will take place. The analysis of a reservoir stress-deformed state alteration is implemented on the different scales through the study of experimental researches applied on a core sample and dynamic characteristics of a reservoir. The post-event analysis of wells with refracturing is implemented where the fracture reorientation was diagnosed by the result of cross-dipole acoustic log surveys and mathematical modeling. Based on the post-event analysis and previously made scientific investigations related to rock mechanics study of a low permeable reservoirs the criterion of secondary fracture reorientation are derived. In order to understand the lower limit of commercial viability for implementing refracturing with fracture reorientation in comparison with refracturing without fracture reorientation the multivariate reservoir simulation is applied. The new approach of refracturing is demonstrated for wells with high risk of fracture’s breakthrough to the water injected front. Solution and risks analysis in such a case is demonstrated. The presented innovational approach allows to increase the quantity of well-candidates for refracturing, to increase the recovery factor of the oilfield, and to minimize the risks while implementing such well stimulation works.
1. Latypov I.D., Fedorov A.I., Nikitin A.N., Issledovanie yavleniya pereorientatsii azimuta treshchiny povtornogo gidrorazryva plasta (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 10, pp. 74-78.
2. Davletova A.R., Kolonskikh A.V., Fedorov A.I., Fracture reorientation of secondary hydraulic fracturing operation (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 11, pp. 110–113.
3. Liu N. et al., Evaluation of refracture reorientation in both laboratory and field scales, SPE 112445, 2008.
4. Roussel P.R., Sharma M.M., Quantifying transient effects in altered-stress refracturing of vertical wells, SPE 119522, 2009.
5. Fedorov A.I., Davletova A.R., Kolonskikh A.V., Toropov K.V., Justification of the necessity to consider the effects of changes in the formation stress state in the low permeability reservoirs development (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2013, no. 2, pp. 25–29.
6. Fedorov A.I., Davletova A.R., Reservoir stress state simulator for determining of fracture growth direction (In Russ.), Geofizicheskie issledovaniya, 2014, V. 15, no. 1, pp. 15-26.
7. Latypov I.D., Borisov G.A., Khaydar A.M. et al., Reorientation refracturing on RN-Yuganskneftegaz LLC oilfields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 6, pp. 34-38.
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A high differentiation of the permeability along the section of the formation is often the reason for premature watering of highly permeable interlayers. The filtration flow almost completely rushes into the impregnated interlayers, while the displacement of oil from the less permeable sections of the section slows down considerably or stops completely. The result is the loss of a significant number of mobile stocks and a low oil recovery factor. To solve this problem, technologies are used, which, depending on the purpose of the treated well, are referred to as equalization technologies of the injectivity profile or the isolation of water inflows. The essence of these technologies is the redistribution of filtration flows by disabling the water absorption intervals or arrival water by injection of grouting mortar, chemical reagents - gels, various colmatants, etc.
The article presents the results of filtration tests on the core of a waterproofing composition intended for processing production and injection wells that operate a layered heterogeneous reservoir. The waterproofing ability of the composition is based on the interaction of the reagent with highly mineralized solutions of calcium or magnesium chlorides with the formation of sediment in the pore space and its colmatation. Due to the good mobility, the composition first penetrates into the most permeable watered layer, turns it off and then penetrates into the less permeable layer. The compatibility of the composition with the oil makes it possible to treat the well with a single filter. Filtration tests of the waterproofing composition were performed using three-layer core models simulating a layered heterogeneous formation for the conditions of the producing and injection wells. Studies have shown the high efficiency of the composition for the redistribution of filtration flows, especially in conditions of the injection well. The use of the composition led to an additional displacement of oil, the increase in the displacement coefficient for the formation models was 0.25-0.30.
1. Stroganov M.A., Technologies for conformance control of injection wells with the use of organosilicon backfill materials of the AKOR group (In Russ.), Neft’. Gaz. Novatsii, 2016, no. 4, pp. 69–73.
2. Abilkhairov D.T., Al’mukhametova E.M., Vladimirov I.V., Results of applying new technology injectivity profile alignment of Gellan as agent plugging (In Russ.), Neftegazovoe delo, 2017, V. 15, no. 1, pp. 65–69.
3. Khasanov I.M., The results of conformance control technologies application at the deposits of Varyeganneftegaz JSC (In Russ.), Neft’. Gaz. Novatsii, 2015, no. 7, pp. 28–33.
4. Usov S.V., Ten’ O.P., Ryabokon’ S.A. et al., Conformance control and water shut-off using gelling agents (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 1991, no. 7, pp. 41–42.
5. Shishlov A.S., Usmanov R.Kh., Azamatov M.A., Kudlaeva N.V., Straightening the injectivity and fluid profile methods based on polymer systems treatment (In Russ.), Georesursy = Georesources, 2010, no. 1(33), pp. 27-30.
6. Khizhnyak G.P., Amirov A.M., Gladkikh E.A. et al., Efficiency of application of water-gas mixtures used to increase oil recovery and rearrange fluid flow (In Russ.), Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2016, V. 15, no. 18, pp. 42–52.
7. Khizhnyak G.P., Amirov A.M., Gladkikh E.A., WAG injection simulation in layered non-uniform reservoir (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 6, pp. 104–107.
8. Khizhnyak G.P., Balueva N.Yu., Mordvinov V.A., Yushkov I.R., Laboratory studies results of polymer oil displacement (In Russ.), Vestnik PGTU. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2006, V. 5, no. 1, pp. 122–125.
9. Khizhnyak G.P., Raspopov A.V., Mordvinov V.A., Yushkov I.R., Research results for the determination of oil displacement efficiency using biopolymers bp-92 (In Russ.), Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2006, V. 5, no. 1, pp. 126–131.
10. Borkhovich S.Yu., Kholmogorova D.K., Vasil’eva E.A., Yatskovskaya A.S., Termopolymeric techniques of development of complex structure fields with viscous and high-viscosity oil in carbon-bearing reservoirs (In Russ.), Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2012, V. 11, no. 2, pp. 95–104.
11. Mordvinov V.A., Poplygin V.V., Poplygina I.S., Methods of polymer flooding of high-viscosity oil pools (In Russ.), Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2015, V. 14, no. 14, pp. 39–51.12. Vezhnin S.A., Nechaev V.K., Application of plasma pulse exposure technology to injectivity profile alignment (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 5, pp. 94–95.
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|OIL RECOVERY TECHNIQUES & TECHNOLOGY|
Development cycle for the oil and gas offshore fields at the closing stage provides for the obligatory well abandonment operation, conducted by the company-operator. The article generalizes Vietsovpetro experience on implementing the process solutions for offshore well abandonment: seawater, polymer-clay drilling mud and calcium chloride solution. Statistics data analysis of technical conditions for suspended/abandoned production strings for the last 10 years showed that the most corrosion activity belongs to seawater. Proportion of abandoned wells having corrosive wear signs, filled with seawater, regardless on oxygen scavenger and corrosion inhibitor additives, is 55 %. The signs of corrosive wear were identified in 45 % of wells, abandoned by polymer-clay solutions, treated with biocides and caustics. Preserving liquids based on calcium chloride mix with corrosion inhibitor additives have almost no corrosion impact on production strings material.
The authors stated main requirements to process solutions for temporary suspension/abandonment of wells on sedimentative stability and corrosion activity. It is indicated, that mostly highlighted criteria met by salt brines based on calcium bromide, formiate of potassium and caesium. Such solutions do not reveal acid properties and have low corrosion activity. For preserving liquids with density 1400–1800 kg/m3 it is recommended to use solutions of potassium formiate and calcium bromide; with density 1800–2000 kg/m3 – mixture of potassium and caesium formiate. Implementation of preserving liquid based on zinc and calcium bromides mixture is not recommended due to possible hydrogen-induced cracking of steel, referred to aggressive types of corrosive wearing.
1. Ivanov A.N., Bushkovskiy A.L., Karapetov R.V. et al., Development of abandonment fluid applied downhole while abandonment of offshore wells (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 8, pp. 100–102.
2. Ivanovskiy V.N., Corrosion of downhole equipment and methods of protection (In Russ.), Inzhenernaya praktika, 2011, no. 3, pp. 18–25.
3. Ryabokon’ S.A., Tekhnologicheskie zhidkosti dlya zakanchivaniya i remonta skvazhin (Process fluids for completion and repair of wells), Krasnodar: Publ. of NPO Burenie, 2002, 274 p.
4. Lamosov M.E., Povyshenie effektivnosti ispol’zovaniya zhidkostey dlya glusheniya i remonta skvazhin na osnove bromidov tsinka i kal’tsiya (Efficiency improvement of use of well-killing and workover fluids f on the basis of zinc bromide and calcium): thesis of candidate of technical science, Krasnodar, 2004.
5. Downs J., Experience in drilling HTHP wells in the North Sea (In Russ.), Neftegazovye tekhnologii, 2008, no. 8, pp. 57–66.
6. Patent no. 2215016 RF, MPK S09K 7/02, E21V 43/12, Process fluid for boring, completion and major repairs of oil and gas wells under abnormally high formation pressure and elevated temperature conditions, Inventors: Natsepinskaya A.M., Fefelov Yu.V., Grebneva F.N., Tataurov V.G., Garshina O.V., Kashbiev Gaysa.
7. Ratent no. 8697611 US, High density brines for use in wellbore fluids, Inventors: Zhang H., Horton R.L., Prasek B.B., Dimataris M.L.K.
8. Ratent no. 7273832 US, Alkali metal tungstate compositions and uses thereof, Inventors: Benton W.J., Magri N.F.9. ASM Handbook. Vol. 13C: Corrosion: Environments and Industries: edited by Cramer S.D., Covino B.S., ASM International, USA, Materials Park (OH), 2006, 1137 p.
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A new bottom water shut-off method is proposed. It provides for automatic injection of the solution of paraffin in diesel fuel into excess water production zone as water cut increases. This results in the formation of a water barrier (or elimination of water breakthrough problems in the existing barrier) and thus reduction of water cut. This method involves providing wells with dual-channel wellhead assembly with two tubing strings run through it. One string is run down the hole to reach the aquifer interval; the other is placed in the oil-bearing zone and equipped with an ins ert pump and a beam unit. Oil and water zones are separated by a packer. Available water shut-off technologies, which imply injection of water shut-off materials directly into formation, do not provide sufficient efficiency in terms of duration of technological effect. As the formed water barrier is not large and water from the water-bearing zone flows quickly around it, water cut increases again. Creation of extended water barrier requires significant costs, so water shut-off treatments become uneconomic.
In summary, application of the proposed method will help increase water shut-off treatments efficiency, and in case of water production thorough the existing water barrier, water breakthrough pathways will be automatically ‘healed’ by injection of paraffin in diesel fuel in to the water production zone without shutting down the well for remedial operations.
1. Kadyrov R.R., Remontno-izolyatsionnye raboty v skvazhinakh s ispol’zovaniem polimernykh materialov (Well isolation squeeze using polymeric materials), Kazan’: Fen Publ., 2007, 423 p.
2. Mukhametshin V.V., Andreev V.E., Dubinsky G.S., Sultanov Sh.Kh., Akhmetov R.T., The usage of principles of system geological-technological forecasting in the justification of the recovery methods, SOCAR Proceedings, 2016, no. 3, pp. 46–51.
3. Kadyrov R.R., Nizaev R.Kh., Yartiev A.F., Mukhametshin V.V., A novel water shut-off technique for horizontal wells at fields with hard-to-recover oil reserves (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 5, pp. 44–47.
4. Zeigman Yu.V., Mukhametshin V.Sh., Khafizov A.R., Kharina S.B., Prospects of application of multi-functional well killing fluids in carbonate reservoirs, SOCAR Proceedings, 2016, no. 3, pp. 33–39.
5. Zeygman Yu.V., Mukhametshin V.Sh., Khafizov A.R. et al., Peculiarities of selecting well-killng fluids composition for difficult conditions (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 1, pp. 66–69.
6. Patent no. 2451165 RF, MPK E 21 B 43/16, Method for restriction of brine water inflow to production well, Inventors: Khisamov R.S., Abdrakhmanov G.S., Nuriev I.A., Taipova V.A., Chepik S.K.
7. Patent no. 2620670 RF, MPK E 21 V 43/32, Method of limitation of produced water inflow to production well, Inventors: Abdrakhmanov G.S., Khisamov R.S., Kadyrov R.R., Khannanov M.T., Khasanova D.K.
8. Patent no. 2386795 RF, MPK E 21 V 43/16, Development method of oil field with water-oil zones, Inventors: Abdulmazitov R.G., Ramazanov R.G., Muzalevskaya N.V., Yakhina O.A., Timergalieva R.R.
9. Ibragimov N.G., Tronov V.P., Gus’kova I.A., Teoriya i praktika metodov bor’by s organicheskimi otlozheniyami na pozdney stadii razrabotki neftyanykh mestorozhdeniy (Theory and practice of methods of struggle with organic varnish in the late stage of development of oil fields), Moscow: Neftyanoe khozyaystvo Publ., 2010, 240 p.
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Maintaining sustainable oil production is possible, largely, due to successful application of technologies for wellbore zone treatment, in particular, selective acidizing of carbonate reservoirs. Reservoir heterogeneity results in poor conformance, uneven distribution of displacement agent, and, consequently, forming of flushed zones with low flow coefficients. This leads to increased water production and higher water cut of produced oil, while, low-permeability layers remain underproduced, or even bypassed. Selective acidizing of productive layers might be a good solution in this case. The mechanism of selective acidizing is based on temporary blocking of flushed (fractured) intervals with some high-viscosity system (a kind of “liquid plug”) inert to acid and solved with oil while production. High-concentration hydrophobic water-in-oil emulsions meet these requirements to the point. They are characterized by a wide range of viscosity control, fr om few dozens of centipoise to dozens of thousands of centipoise, up to non-flowing, as well as by controllable physical properties, including yield point (static and dynamic shear stress), thixotropic properties (structure strengthening with time), non-Newtonian rheology (pseudoplastic and/or viscoelastic flow).
This paper presents results of studies aimed at development of special formulations of high-concentration hydrophobic emulsions to be used in challenging conditions of fractured-cavernous reservoirs, wh ere conventional hydrophobic emulsions fail to block permeable zones and direct acid systems to target intervals. The designed formulation of high-concentration hydrophobic emulsion provides for enhanced blocking properties needed to redirect the injected acid systems from the fractured (and, as a rule, water-saturated) zones to oil-saturated matrix zones, high-performance killing of wells during workover operations, and enhanced water shutoff properties, resulting in overall cost saving.
1. Musabirov M.Kh., Sokhranenie i uvelichenie produktivnosti neftyanykh plastov (Preserving and increasing the productivity of oil reservoirs), Kazan’: FEN Publ., 2007, 424 p.
2. Orlov G.A., Musabirov M.Kh., Ispol'zovanie osobennostey reologofil'tratsionnykh svoystv kontsentrirovannykh obratnykh emul'siy dlya napravlennogo fiziko-khimicheskogo vozdeystviya na plast (Using the rheology-filtering properties of concentrated reverse emulsions for directed physicochemical effect on the formation), Collected papers “Problemy kompleksnogo osvoeniya trudnoizvlekaemykh zapasov nefti i prirodnykh bitumov (dobycha i pererabotka)” (Problems of integrated development of hard-to-recover oil and natural bitumen reserves (mining and processing)), Part 2 “Neft' i bitumy” (Oil and bitumen), Proceedings of International Conference, 1994, pp. 657–662.
3. Musabirov M.Kh., Razrabotka kompleksa tekhnologiy sokhraneniya i uvelicheniya produktivnosti pri vskrytii i ekspluatatsii neftyanykh plastov (Development of a complex of technologies for conservation and increase in productivity in the completion of a well and operation of oil reservoirs): thesis of doctor of technical science, Bugul'ma, 2007.
4. Mirzadzhanzade A.Kh., Reologicheskie problemy neftegazootdachi (Rheological problems of oil and gas recovery), Moscow: Publ. of VNIIOENG, 1986, 51 p.
5. Glushchenko V.N., Silin M.A., Neftepromyslovaya khimiya (Oilfield chemistry), Part 4. Kislotnaya obrabotka skvazhin (Well acidizing), edited by Mishchenko I.T., Moscow: Interkontakt Nauka Publ., 2010, pp. 607–624.
6. Orlov G.A., Kendis M.Sh., Glushchenko V.N., Primenenie obratnykh emul'siy v neftedobyche (Application of inverse emulsions in oil production), Moscow: Nedra Publ., 1991, 225 p.7. Glushchenko V.N., Obratnye emul'sii i suspenzii v neftegazovoy promyshlennosti (Inverse emulsions and suspensions in the oil and gas industry), Moscow: Interkontakt Nauka Publ., 2008, 725 p.
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The paper gives successful practices of casing leak repair using fiberglass scab liner in RN-Purneftegas LLC. The scope of the method effective application and criteria of selection of wells candidates are defined. Fiberglass scab liner solves the same problems as steel scab liner but the first one has much higher corrosion resistance and could be easily withdrawn by drilling-out. In total fiberglass scab liners installed in six wells, the technology allowed to produce more than 12 thousand tons of incremental oil, in three wells effect continues. The pilot introduction stages of the technology on the example of the well of Tarasovskoye field are given. In the well of Komsomolskoye field reserve recovery drawn have led to the need for well re-completion by sidetracking. During this fiberglass scab liner was successfully drilled, confirming the possibility of withdrawing it from the well if necessary. The analysis of outcomes of the carried-out works allows to draw a conclusion on applicability fiberglass scab liner for isolation of extended untight sites of casing string. The disadvantages of the technology include the inability to set packer equipment in the scab liner during subsequent well intervention. The advantage of the technology include the possibility of a prolonged operation of wells in conditions of high corrosiveness of the produced product, running downhole standard tools, drilling scab liner if necessary (e.g., in case of mechanical damage, detection of a new interval of casing leak, sidetracking in the previously isolated interval).
1. Nigmatullin T.E., Presnyakov A.Yu., Strizhnev V.A., Nikishov V.I., Casing leak repair using fiberglass scab liner (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2013, no. 2, pp. 44–47.2. Utility patent no. 125620 RF, MPK E21V 29/10, E21V 33/13, Ustroystvo dlya remonta ekspluatatsionnoy kolonny ili selektivnoy izolyatsii plastov (Device for repair of production string or selective isolation of layaers), Inventors: Nikishov V.I., Bochkarev V.K., Kamenev A.N., Mamedov T.M., Malykhin I.A., Solov'ev Yu.S., Yakovlev S.S., Presnyakov A.Yu., Nigmatullin T.E.
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|OIL FIELD EQUIPMENT|
Problem of efficient utilization of low-pressure gas and effective pumping of gas-liquid mixtures is one of the unsolved environmental problems in petroleum industry. This is because the problem of development of effective pumping and compressor equipment for gas and gas-liquid mixtures in field conditions has not been fully solved. The direction of work on the joint use of inkjet technology and power pumps that allow the transfer of multiphase media is very promising. Application of centrifugal pumps with two output channels allow to increase the efficiency of the working process, and the practical interest in such hydraulic machines has not weakened for dozens of years. A multi-stage centrifugal pump with two output channels, assigned to a group of dual-flow pumps, allows to create a two-chamber jet pump-compressor unit. In two-chamber pump-and-compressor unit the pumped gas-liquid mixture is compressed in series in two working chambers: in the working chamber of the jet device and in the working chamber of a multi-stage centrifugal pump. In the course of the research work, calculation algorithms have been developed that make it possible to relate the theory of jet devices to the theory of centrifugal and rotary pumps, as applied to two-chamber pump-compressor units. It is shown that the characteristics of the centrifugal pump under study cannot be represented in the form of a simple linear relationship between the pump flow and pressure. Instead of a line on the coordinate plane, it is required to represent two plane figures graphically. One of the figures allows us to characterize the flow parameters in the first output channel of the pump, and the second one allows us to characterize the flow parameters in the second output channel of the pump. In this case, a definite flow regime in the first output channel of the pump corresponds to a strictly defined flow regime in the second output channel of the pump. In the study along with a centrifugal multi-stage pump, new designs of volume-type pumps that can operate at high rotor speed are considered. The possibility of assembling a multi-stage pump, where sections of a dynamic-type pump and a volume-type pump sections are sequentially mounted on one shaft is also considered. Prospects for the use of two-chamber pump-compressor units are also associated with the development of new technologies for the production of high-viscosity oil, where the issues of creating efficient thermal generators and efficient pumping systems remain very topical.
Acknowledgement. The works are carried out with the financial support of the state represented by the Ministry of Education and Science of Russia. The unique identifier of the work (project) is RFMEFI57717X0259.
1. Patent no. 2315656 US, Dual pressure pumping system, Inventors: Rhoda R.
2. Drozdov N.A., Issledovanie fil'tratsionnykh kharakteristik pri vytesnenii nefti vodogazovymi smesyami i razrabotka tekhnologicheskikh skhem nasosno-ezhektornykh sistem dlya vodogazovogo vozdeystviya na plast (Investigation of filtration characteristics in the displacement of oil by water-gas mixtures and development of technological schemes of pumping-ejector systems for WAG): thesis of candidate of technical science, 2012.
3. Sazonov Yu.A., Degovtsov A.V., Kazakova E.S., Klimenko K.I., Multi-flow ejector and a new direction for the development of inkjet technology (In Russ.), Territoriya NEFTEGAZ, 2012, no. 4, pp. 75-77, URL: http://www.neftegas.info/upload/uf/3b9/tng42012.pdf
4. Utility model no. 158649, Nasos – dispergator (Shear pump), Inventors: Sazonov Yu.A., Mokhov M.A., Aseev V.I.5. Sazonov Iu.A., Mokhov M.A., Tumanyan Kh.A., Developing special turbine for rational utilization of reservoir energy of hydrocarbon deposits, Indian Journal of Science and Technology, 2016, V. 9(42), DOI: 10.17485/ijst/2016/v9i42/104275, November, URL: http://www.indjst.org/index.php/indjst/article/view/104275/ 74819.
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|OIL TRANSPORTATION & TREATMENT|
Offshore oil-and-gas production is characterized by the limited space for field equipment allocation and power units capacity. Accompanying the subsea pipelines construction and maintenance difficulty, this also limits the transportation capacity of products, produced fr om remote wellhead platforms. The article covers the methods which exist in Vietsovpetro JV in terms of reduction of pressure losses during transportation, reduction of wells buffered pressure and improvement of wells production rate. The article provides results on optimization of oil and gas transportation at South and Central Dragon fields areas, wh ere operation of wellhead platform RC-5 and step-wise commissioning of new wells at wellhead platform RC-9 with uncompleted construction of a new gas pipeline RC-5/9 – RP-1 follows the increase of gas and liquid production. To reduce the pressure in oil transportation system RC-DM – RC-4 – RC-5 – RP-1, the technology on transporting the part of associated gas RC-5/9 together with the oil to RP-1 was developed. To that purpose, the adjustable choke at RC-5 was designed and implemented to separate the part of associated gas and direct it to the gas-saturated oil flow. The conducted operation resulted in reducing the pressure within oil and gas transportation system on indicated RCs. During gas injection in amount of 90 thousand m3/day, the pressure in the RC-DM slug catcher reduced from 2,12 till 1,9 MPa, at RC-4 – from 2.03 till 1.8 MPa, at
RC-5 – from 2.2 till 1.75 atm. Additional production volume increased averagely by 327 m3/day for liquids (162 t/day for oil), which gave 11.2 % increment. The economic effect from optimisation within the applied period was more than 1.2. mln USD.
1. Nguyen Thuc Khang, Tong Canh Son, Akhmadeev A.G., Le Dinh Hoe, Bezopasnyy transport vysokoparafinistykh neftey morskikh mestorozhdeniy v usloviyakh nizkoy proizvoditel’nosti (Secure transport of high-paraffin oil of offshore fields in conditions of low productivity), Proceedings of XX Petersburg International Energy Forum, St. Petersburg, 2010, pp. 154–157.
2. Nguyen Thuc Khang, Tong Canh Son, Akhmadeev A.G. et al., Opyt puska i ekspluatatsii truboprovodov s nizkoy proizvoditel’nost’yu, perekachivayushchikh vysokoparafinistye nefti (Experience in start-up and operation of the pipelines with low productivity, pumping highly paraffinic oil), Proceedings of the conference “SP “V’etsovpetro” – 30 let sozdaniya i razvitiya” (Vietsovpetro JV – 30 years of establishment and development), Vungtau, 2011, pp. 86–94.
3. Akhmadeev A.G., Tong Canh Son, Ivanov S.A., Comprehensive approach to provide high-paraffin oil transportation from the offshore fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 6, pp. 100–103.4. Tu Thanh Nghia, Krupenko E.V., Ivanov A.N. et al., Optimizatsiya dobychi i sbora mul’tifaznoy produktsii neftyanykh skvazhin na shel’fovykh mestorozhdeniyakh (na primere mestorozhdeniy SP “V’etsovpetro” (Optimization of production and collection of multiphase production of oil wells in offshore fields (On an example of Vietsovpetro JV’ fields)), Proceedings of scientific conference on the 35th anniversary of the creation of the Vietsovpetro JV, Vungtau, 2016, p. 25.
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Underwater crossings of main pipelines belong to the most critical areas of the pipelines. Their performability must be considered from the perspective of the requirements of the provision and management of security, because damage with the loss of integrity may lead to serious environmental consequences.
Currently Transneft PJSC operates about 1400 of underwater crossings constructed by one of three methods: trench method, directional drilling, microtunnelling. In the construction of underwater crossing by trench method, special attention must be paid to the mutual influence of channel processes of water and an object underwater crossing in order to prevent deviations from the horizontal and vertical position. Critical deviations occur within weakly stable channels of water of object with intense bed processes, in which erosion of the floodplain and banks of hundreds of meters, and the erosion of the bottom – up to several meters per year. Method of the directional drilling has several advantages over the trench method of construction: shorter construction times, a weak influence of natural and anthropogenic impacts on the underwater passage, in cramped conditions, regardless of the time of year, comparable in some cases the cost of construction and installation works. Microtunnelling method should be used in difficult engineering-geological conditions. For example, the reliability of the underwater crossing with seismic activity up to 7 points on MSK-64 is provided by structural strength microtunnelling passage.
The article covers technical and economic aspects of construction of the pipeline route. Constraints are formulated methods of construction of underwater passages of main pipelines. Technological scheme for selecting a method of construction of main pipelines underwater passages is developed.
1. Makhutov N.A., Prochnost' i bezopasnost': fundamental'nye i prikladnye issledovaniya (Strength and safety: fundamental and applied research), Novosibirsk: Nauka Publ., 2008, 528 p.
2. Promyshlennaya bezopasnost' i nadezhnost' magistral'nykh truboprovodov (Industrial safety and reliability of main pipelines): edited by Vladimirov A.I., Kershenbaum V.Ya., Moscow: Publ. of National Institute of Oil and Gas, 2009, 696 p.
3. Sharafutdinov Z.Z., Parizher V.I., Sorokin D.N. et al., Stroitel'stvo perekhodov magistral'nykh truboprovodov cherez estestvennye i iskusstvennye prepyatstviya (Construction of crossings of trunk pipelines through natural and artificial obstacles), Novosibirsk: Nauka Publ., 2013, 339 p.
4. Borodavkin P.P., Berezin V.L., Shadrin O.B., Podvodnye truboprovody
(Underwater pipelines), Moscow: Nedra Publ., 1979, 415 p.
5. Ivantsov O.M., Construction of crossings of trunk pipelines through active tectonic faults (In Russ.), Zhurnal neftegazovogo stroitel'stva, 2013, no. 4, pp. 25–31.6. Vafin D.R., Sapsay A.N., Shatalov D.A., Technical and economic limits to the application of the horizontal direction drilling method in the construction of underwater transitions of main pipelines (In Russ.), Nauka i tekhnologii truboprovodnogo transporta nefti i nefteproduktov, 2017, no. 7(3), pp. 66–73.
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|ENVIRONMENTAL & INDUSTRIAL SAFETY|
The transfer of oily wastes to secondary raw materials is provided by a reagent method of oil sludge utilization according to the priority goals in science and technology – rational nature management. The aim of the article is to reduce environmental pollution in oil production and natural gas preparation by creating new technologies of hydrocarbon wastes utilization with the formation of recovery products by encapsulating chemical contaminants during the hydration of calcium oxide and the formation of insoluble silicates that increase the efficiency of the DCR process (Dispersion by chemical reaction with alkali earth metals oxides). To provide ecological safety to the product of utilization three components were used in the decontamination composition: calcium oxide, spent silica-containing sorbents – diatomite filter powder enriched with plant wax substances, and silica gel. Silica-containing sorbent promotes the formation of insoluble calcium silicates, reducing the solubility of the capsules of the product of utilization. Possessing the residual properties of the sorbent it adsorbs the heavy metals and hydrocarbons contained in the oil sludge. The process is carried out by successive mixing oily waste preliminarily heated up to the temperature of 80-85°C with oil and fat industry wastes at a ratio of 1: (0.1-0.3) by weight and quicklime with water in the amount of 62-91% îf wastes until the formation of a homogeneous hydrophobic loose fine powder. Joint utilization of oil sludge and spent silica gel that's the waste of the natural gas preparation unit for transport, ensures minimal migration of harmful substances into the environment from waste products which are suitable for use in construction, in particular, as a complex organomineral additive in expanded clay and activated mineral powder in asphalt concrete mixtures.
1. State report “On the state and protection of the environment of the Russian Federation in 2015”, Moscow: Publ. of RF Ministry of Natural Resources; NIA-Priroda, 2016, 639 p.
3. Litvinova T.A., Ekologicheskie aspekty obezvrezhivaniya i utilizatsii uglevodorodsoderzhashchikh otkhodov neftegazovogo kompleksa (Environmental aspects of disposal and recycling of hydrocarbon containing wastes oil and gas industry): thesis of candidate of technical science, Krasnodar, 2011.
4. Litvinova T.A., Tsokur O.S., Kosulina T.P., Solution of the problem of oil-containing waste utilization with their involvement in resource cycle (In Russ.), Sovremennye problemy nauki i obrazovaniya, 2012, no. 6, p. 53.
5. Tsokur O.S., Litvinova T.A., Kosulina T.P., Primenenie nailuchshikh dostupnykh tekhnologiy dlya utilizatsii promyshlennykh otkhodov (The application of the best available technologies for the disposal of industrial waste), Proceedings of IV International Scientific Ecological Conference “Problemy rekul'tivatsii otkhodov byta, promyshlennogo i sel'skokhozyaystvennogo proizvodstva” (Problems of household, industrial and agricultural production waste reclamation), Krasnodar: Publ. of Kuban State Agrarian University, 2015, Part 1, pp. 728–732.
6. Mobil'nye avtomatizirovannye kompleksy (Mobile automated systems), URL: http://www.insteb.ru/articles/2.html.
7. Kosulina T.P., Antoniadi D.G., Tsokur O.S., Maksimovich V.G., Reducing the ecological hazards on the territory of oil deposites in Krasnodar region by utilization of oily waste using reagent method (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 12, pp. 158–160.
8. Litvinova T.A., Vinnikova T.V., Kosulina T.P., On reagent method of oil-slimes neutralization (In Russ.), Ekologiya i promyshlennost' Rossii, 2009, no. 10, pp. 40–43.
9. Kosulina T.P., Kononenko E.A., Increasing environmental safety of product recycling oil sludg (In Russ.), Politematicheskiy setevoy elektronnyy nauchnyy zhurnal Kubanskogo gosudarstvennogo agrarnogo universiteta, 2012, V. 78, URL: http://ej.kubagro.ru/2012/04/pdf/64.pdf.
10. Kosulina T.P., Tsokur O.S., Litvinova T.A., Use of detoxifying composition for utilization of oil sludge and spent sorbent ODM-2F (In Russ.), Ekologicheskiy vestnik nauchnykh tsentrov Chernomorskogo ekonomicheskogo sotrudnichestva, 2013, no, 3, pp. 77-84.
11. Tsokur O.S., Povyshenie resursosberezheniya utilizatsiey neftesoderzhashchikh otkhodov reagentnym sposobom s polucheniem ekologicheski bezopasnykh produktov (Increase of resource saving by utilization of oil-containing wastes by reagent method with obtaining environmentally safe products): thesis of candidate of technical science, Krasnodar, 2015.
12. Patent no. 2395466 RF, Method of decontaminating oily mud, Inventors: Kosulina T.P., Litvinova T.A.
13. Kosulina T.P., Al'varis Ya.A., Solntseva T.A., Research into oil and gas complex solid wastes and their usage as a secondary raw material. Part 1. The composition and structure of contaminants forming on the surface of silica gel in natural gas preparation for transport (In Russ.), Zashchita okruzhayushchey sredy v neftegazovom komplekse, 2008, no. 1, pp. 16–20.
14 Kosulina T.P., Solntseva T.A., Levashov A.S., Al'varis Ya.A., Research into oil and gas complex solid wastes and their usage as a secondary raw material. Part 3. About contaminants structure and danger class of exhausted silica gel – the waste of gas processing industry (In Russ.), Zashchita okruzhayushchey sredy v neftegazovom komplekse, 2009, no. 2, pp. 33–38.
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