Presence of sand, paraffin, H2S, hydrates and salts in producing wells usually lead to complications and frequent remedial works related thereto during operation of oil, gas-oil and gas condensate fields. Such complications during offshore wells operations are worsen and dragged due to metocean conditions, which often prevent smooth and well-timed normalizing of well performance. Sea conditions require thorough attention to preventive measures on asphaltene sediments control in well and oil-field equipment. Presence of resins and asphaltenes lead to wax crystallisation. Existence of sand, clay particles and other solids within the oil contributes to asphaltene sediments hardening, often acting as the centres of paraffin crystallisation.
The article covers the experience of asphaltene sediments control during oil production at White Tiger field. White Tiger field oil is highly paraffinic, with high content of resins and asphaltenes. That creates a number of serious challenges. One of the main factors that complicate the well operation, is the asphaltene sediments deposition on the surface of the downhole equipment, which leads to a reduced workover interval and decreased operational efficiency of the production well stock. The available field data obtained from White Tiger wells performance with applied wire-line operations, indicate the most intense paraffin deposition in the tubing from 1000 m to the well head. Paraffin crystals generate from 1500 m, while at 1000 m paraffins are deposited in a high volume.
References
1. Veliev M.M., Zung L.V., Determination of physical and chemical characteristics of asphalt-tar-wax depositions in flow tubing (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2014, no. 2(96), pp. 88–96.
2. Zung L.V., Veliev M.M., Asphaltene deposits removing and scale prevention (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2014, no. 3 (97), pp. 45–54.
3. Nasyrov A.M., Sposoby bor'by s otlozheniyami parafina (Ways to deal with deposits of paraffin), Moscow: Publ. of VNIIOENG, 1991, 44 p.
4. Nguen T.K., Nguen T.V., Akhmadeev A.G., Veliev M.M., Prevention of deposition and removal of deposits existing in the well tubing and in the process equipment (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2011, no. 2(84), pp. 30–39.
