Restricting the use of gas enhanced oil recovery methods for low-permeability reservoirs, including pressures exceeding 40-60 MPa, is caused by high capital costs for increasing the injection pressure of the displacing agent. The paper proposes a solution aimed at improving the efficiency of the development of low-permeability oil deposits in multilayer oil and gas fields by using gas or gas condensate deposits of this field as a source of the injected agent. Oil and gas deposits must intersect in plan. The solution does not imply the use of equipment for increasing the gas pressure during injection into the oil reservoir, but provides for the use of equipment to control and regulate the pressure and flow rate of the injected agent. For the considered conditions of the Achimov deposits with abnormally high pressure, the proposed method of developing a low-permeability oil reservoir of a multilayer oil and gas condensate field is implemented in two stages. At the first stage, the oil reservoir is developed by depletion by one of the known systems of horizontal wells with multi-stage hydraulic fracturing. At the second stage, some of the wells are perforated at a depth of gas or gas condensate formation and downhole equipment is installed for simultaneous separate production and compressorless gas injection. Simulation of the proposed method was carried out in the compositional simulator GEM (CMG) to reproduce the process of miscible displacement of oil by hydrocarbon gas. As a result of a series of multivariate calculations of technological development indicators, restrictions on the bottomhole pressure of injection wells were obtained, which ensure the achievement of the maximum recovery factor under the given conditions. The estimation of the minimum ratio of gas volume of a gas reservoir to the volume of oil of an oil reservoir for the implementation of the method is carried out.
1. Soin D.A., Skorobogatov V.A., Kovaleva E.D., Peculiarities of estimating potential hydrocarbon resources of Achim and Lower-Middle- Jurassic deposits at northern regions of Western Siberia (In Russ.), Vesti gazovoy nauki, 2016, no. 1 (25), pp. 16–22.
2. Messoyakhaneftegaz nachal polnomasshtabnuyu razrabotku achimovskikh zalezhey (Messoyakhaneftegaz begins full-scale development of the Achimov deposits), Neftegaz.RU, URL: https://neftegaz.ru/news/dobycha/499621-messoyakhaneftegaz-nachal-polnomasshtabnuyu-razrabotku-achim...
3. Lake L.W., Enhanced oil recovery, Prentice Hall, Cop., 1989, 550 p.
4. Boyko V.S., Razrabotka i ekspluatatsiya neftyanykh mestorozhdeniy (Development and operation of oil fields), Moscow: Nedra Publ., 1990, 427 p.
5. Nazarova L.N., Karpov S.N., Evaluation of efficiency of gas injection technology in low-permeable multiplayer objects (In Russ.), Territoriya neftegaz, 2019, no. 9, pp. 58–63.
6. Patent RU 1239276 SU, Method of sustaining formations pressure in oil reservoir, Inventor: Aliev A.I.
7. Patent RU 2295632 C1, Method for well drilling and development of multihorizon hydrocarbon field characterized by non-uniform geological conditions of productive bed attitudes, Inventors: Vitjazev O.L., Dorofeev A.A., Medvedskij R.I., Popov A.P., Rjazanov A.N., Khajrullin B.J., Khudajnatov E.J.
8. Patent SU 1678110 A1, Method of developing oil and gas-condensate pool with oil and gas condensate beds situated one over the other, Inventors: Stepanova G.S., Skripka V.G., Konyshev B.I., Zhustarev V.V., Mordukhaev M.Kh., Mosina A.A.
9. Vafin T.R., Sovershenstvovanie tekhnologiy vodogazovogo vozdeystviya na plast na nestatsionarnom rezhime (Improvement of technologies for water-gas stimulation of the reservoir in a non-stationary mode): thesis of candidate of technical science, Bugul'ma, 2016.
10. Patent RU 2737043 C1, Method for development of oil reservoir of multi-layer oil and gas condensate deposit, Inventors: Pyatibratov P.V., Kalinin D.S.
11. Krasnoborov S.V., Byakov A.V., Evaluation of injection agent selection for Achimovsky deposits development in Western Siberia with hard to recover oil and abnormally high formation pressure (In Russ.), Burenie i neft', 2014, no. 9, pp. 44–46.