In recent years, fields with hard-to-recover oil reserves have been actively developed. This is facilitated, among other things, by government support in the form of tax benefits. However, in order to get these benefits, oil reserves must meet the criteria of being classified as hard-to-recover. One of the criteria according to the order of the Ministry of Natural Resources and Environment of the Russian Federation from 15.05.2014 № 218 "On approval of the Procedure for determination of permeability and effective oil saturated thickness of the reservoir for hydrocarbon deposits" hard-to-recover reserves include deposits characterized by permeability of less than 2·10-3 mcm2. In order to substantiate the permeability coefficient for a deposit, petrophysical dependence of permeability on porosity is plotted based on the results of core testing. In case of small or unrepresentative core samples, the investigated samples may not cover all variations of physical and lithological characteristics across the formation. In this connection, the value of permeability coefficient of the deposit can be overestimated and there is no possibility to get tax benefits. The work presents a methodology that will allow evaluation of the possibility of substantiating preferential permeability in low-permeability formations with non-representative sampling, while conducting additional core studies.
This approach is based on the estimation of the refined petrophysical relationship of permeability and porosity taking into account the distribution of porosity coefficient based on well logging data. Application of the method will allow identification of low-permeability deposits with the potential to receive tax benefits after additional core studies.
References
1. Order of the Ministry of Natural Resources and Environment of the Russian Federation No. 218 dated 15.05.2014 “Ob utverzhdenii Poryadka opredeleniya pokazateley pronitsaemosti i effektivnoy neftenasyshchennoy tolshchiny plasta po zalezhi uglevodorodnogo syr'ya” (On approval of the Procedure for determining the permeability indicators and effective oil-saturated thickness of a formation for a hydrocarbon deposit).
2. Order of the Ministry of Natural Resources and Environment of the Russian Federation No. 824 dated 02.11.2021 “Ob utverzhdenii stratigraficheskikh kharakteristik (sistema, otdel, gorizont, plast) zalezhey uglevodorodnogo syr'ya dlya tseley ikh otneseniya k bazhenovskim, abalakskim‚ khadumskim, domanikovym produktivnym otlozheniyam, a takzhe produktivnym otlozheniyam tyumenskoy svity v sootvetstvii s dannymi gosudarstvennogo balansa zapasov poleznykh iskopaemykh” (On approval of stratigraphic characteristics (system, series, horizon, layer) of hydrocarbon deposits for the purposes of classifying them as Bazhenov, Abalak, Khadum, Domanik productive deposits, as well as productive deposits of the Tyumen suite in accordance with data from the state balance of mineral reserves).
3. Patrakov D.P., Plitkina Yu.A., Glebov A.S., Development experience of low permeable reservoirs of Tyumen suite of Krasnoleninskoye field RN-Nyaganneftegas JSC (In Russ.), Neftyanaya provintsiya, 2019, no. 2, pp. 72–100.
4. Valiullin R.A., Vakhitova G.R., Tokareva D.S., Shaybekova G.F., Justification of the atitude to the hard-to-remove reserves of the Middle Jurassic sediments of the Tyumen formation of the Sredne-Ugutsky oilfield (In Russ.), Geologiya. Izvestiya otdeleniya nauk o zemle i prirodnykh resursov, 2021, no. 28, pp. 3–11.
5. Bobyleva A.Z., Gosudarstvennoe antikrizisnoe upravlenie v neftyanoy otrasli (State anti-crisis management in the oil industry), Moscow: Yurayt Publ., 2018, 326 p.
6. Shchekaturova I.Sh., Kolomasova S.A., Antonov M.S., Kuz'michev O.B., On the economic feasibility of developing fields with hard-to-recover oil reserves (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 2, pp. 18–21, DOI: https://doi.org/10.24887/0028-2448-2021-2-18-21
7. Boldyrev E.S., Nikulochkina D.A., Khafizova L.K., Gareev R.R., Management of oil and gas field development using tax incentives (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 8, pp. 6–10, DOI: https://doi.org/10.24887/0028-2448-2020-8-6-10
8. D'yachkov G.S., Comparative analysis of tax regimes effectiveness in oil production (In Russ.), Uchet. Analiz. Audit, 2022, no. 9(3), pp. 39–51,
DOI: https://doi.org/10.26794/2408-9303-2022-9-3-39-51 UDK 336.201.3(045)
9. Order of the Ministry of Natural Resources and Environment of the Russian Federation No. 867 dated 12.12.2022 “Ob utverzhdenii stratigraficheskikh kharakteristik (sistema, otdel, gorizont, plast) zalezhey uglevodorodnogo syr'ya dlya tseley ikh otneseniya k bazhenovskim, abalakskim, khadumskim, domanikovym, achimovskim produktivnym otlozheniyam v sootvetstvii s dannymi gosudarstvennogo balansa zapasov poleznykh iskopaemykh” (On approval of stratigraphic characteristics (system, series, horizon, layer) of hydrocarbon deposits for the purposes of classifying them as Bazhenov, Abalak, Khadum, Domanik, Achimov productive deposits in accordance with data from the state balance of mineral reserves).
