Mineral analysis of complex reservoirs based on the results of interpretation of pulsed neutron gamma-ray spectroscopy logging

UDK: 550.8.05
DOI: 10.24887/0028-2448-2021-8-27-29
Key words: mineralogical composition, pulsed neutron gamma-ray spectrometric logging, inelastic scattering, radiation capture, weight concentration of an element, well log analysis, X-ray fluorescence analysis
Authors: G.R. Vakhitova (Bashkir State University, RF, Ufa), R.F. Sharafutdinov (Bashkir State University, RF, Ufa), A.R. Bikmetova (Bashkir State University, RF, Ufa)

Assessment of the mineralogical composition of rocks is very important for a detailed lithological description of the section. This is especially important when the section is represented by rocks with a complex geological structure, such as heterogeneous limestones and dolomites, or sandy-argillaceous rocks with a multicomponent composition. In addition, to assess the effect of clay content on porosity, it is necessary to know the type of clay and its mineralogical composition. X-ray fluorescence analysis (XRF) of core samples is a direct method for studying the composition of rocks. However, the core is not available in all wells, not in the entire depth interval; therefore, the mineralogical composition of rocks is estimated based on the recorded data of pulsed neutron gamma ray spectrometric logging. Interpretation of these data is a rather complicated process and consists of primary processing of the recorded spectra and interpretation itself. The primary processing of the recorded spectra is carried out according to a certain technology, and the interpretation itself is based on the well-known geochemical model of oxides.

This article presents the results of the work of Bashkir State University on the data of primary processing and interpretation of spectra recorded by the device AINK-PL provided by VNIIA named by N.L. Dukhov. A quantitative interpretation of well logging data has been performed. Comparison of the results obtained in the work with the data of core analysis showed good agreement in the quantitative assessment of the mineral composition of rocks.

References

1. Bubeev A.A., Velizhanin V.A., Loboda N.G., A method and an algorithm for the processing of the neutron gamma-ray spectrometry logging data obtained by an SNGK-89 tool (In Russ.), Karotazhnik, 2011, no. 8(206), pp. 55–72.

2. Velizhanin V.A., Bortasevich V.S., Loboda D.R. et al., Instruktsiya po provedeniyu impul'snogo spektrometricheskogo neytronnogo gamma-karotazha apparaturoy serii AIMS i obrabotke rezul'tatov (Instructions for carrying out pulsed spectrometric neutron gamma-ray logging with the AIMS series equipment and processing the results), Tver: Publ. of Neftegazgeofizika, 2004, 81 p.

3. Khomyakov A.S., Importozameshchayushchaya geofizicheskaya apparatura proizvodstva FGUP VNIIA: Vserossiyskiy nauchno-issledovatel'skiy institut avtomatiki im. N.L. Dukhova (Import-substituting geophysical equipment produced by VNIIA: Federal State Unitary Enterprise Dukhov Automatics Research Institute), 2019, 33 p., URL: http://oilandgasforum.ru/data/files/homyakov.pdf.

4. Oyinkansola Modupe Ajayi, Numerical simulation and interpretation of neutron-induced gamma ray spectroscopy measurements: PhD dissertation, Texas: The University of Texas at Austin, 2015, 333 p.

5. Aboud M., Badry R.A., Grau J., Herron S.L., High-definition spectroscopy – determining mineralogic, Oilfield Review, 2014, V.26(1), pp. 34-50.

6. Khisamutdinov A.I., Banzarov B.V., Fedorin M.A., Matematicheskoe modelirovanie nestatsionarnogo perenosa chastits v zadachakh impul'snogo neytronnogo gamma–karotazha (Mathematical modeling of non-stationary particle transport in the problems of pulsed neutron gamma-logging), Novosibirsk: Publ. of IPGG SB RAS, 2008, 54 p.

Assessment of the mineralogical composition of rocks is very important for a detailed lithological description of the section. This is especially important when the section is represented by rocks with a complex geological structure, such as heterogeneous limestones and dolomites, or sandy-argillaceous rocks with a multicomponent composition. In addition, to assess the effect of clay content on porosity, it is necessary to know the type of clay and its mineralogical composition. X-ray fluorescence analysis (XRF) of core samples is a direct method for studying the composition of rocks. However, the core is not available in all wells, not in the entire depth interval; therefore, the mineralogical composition of rocks is estimated based on the recorded data of pulsed neutron gamma ray spectrometric logging. Interpretation of these data is a rather complicated process and consists of primary processing of the recorded spectra and interpretation itself. The primary processing of the recorded spectra is carried out according to a certain technology, and the interpretation itself is based on the well-known geochemical model of oxides.

This article presents the results of the work of Bashkir State University on the data of primary processing and interpretation of spectra recorded by the device AINK-PL provided by VNIIA named by N.L. Dukhov. A quantitative interpretation of well logging data has been performed. Comparison of the results obtained in the work with the data of core analysis showed good agreement in the quantitative assessment of the mineral composition of rocks.

References

1. Bubeev A.A., Velizhanin V.A., Loboda N.G., A method and an algorithm for the processing of the neutron gamma-ray spectrometry logging data obtained by an SNGK-89 tool (In Russ.), Karotazhnik, 2011, no. 8(206), pp. 55–72.

2. Velizhanin V.A., Bortasevich V.S., Loboda D.R. et al., Instruktsiya po provedeniyu impul'snogo spektrometricheskogo neytronnogo gamma-karotazha apparaturoy serii AIMS i obrabotke rezul'tatov (Instructions for carrying out pulsed spectrometric neutron gamma-ray logging with the AIMS series equipment and processing the results), Tver: Publ. of Neftegazgeofizika, 2004, 81 p.

3. Khomyakov A.S., Importozameshchayushchaya geofizicheskaya apparatura proizvodstva FGUP VNIIA: Vserossiyskiy nauchno-issledovatel'skiy institut avtomatiki im. N.L. Dukhova (Import-substituting geophysical equipment produced by VNIIA: Federal State Unitary Enterprise Dukhov Automatics Research Institute), 2019, 33 p., URL: http://oilandgasforum.ru/data/files/homyakov.pdf.

4. Oyinkansola Modupe Ajayi, Numerical simulation and interpretation of neutron-induced gamma ray spectroscopy measurements: PhD dissertation, Texas: The University of Texas at Austin, 2015, 333 p.

5. Aboud M., Badry R.A., Grau J., Herron S.L., High-definition spectroscopy – determining mineralogic, Oilfield Review, 2014, V.26(1), pp. 34-50.

6. Khisamutdinov A.I., Banzarov B.V., Fedorin M.A., Matematicheskoe modelirovanie nestatsionarnogo perenosa chastits v zadachakh impul'snogo neytronnogo gamma–karotazha (Mathematical modeling of non-stationary particle transport in the problems of pulsed neutron gamma-logging), Novosibirsk: Publ. of IPGG SB RAS, 2008, 54 p.


Attention!
To buy the complete text of article (a format - PDF) or to read the material which is in open access only the authorized visitors of the website can. .

Mobile applications

Read our magazine on mobile devices

Загрузить в Google play

Press Releases

24.11.2021
23.11.2021
02.11.2021
Конкурс на соискание молодежной премии имени академика И.М. Губкина