The article is related to the commissioning of a new oil and gas production cluster of Rosneft Oil Company in the Irkutsk region. The Osinsky productive horizon of the Lower Cambrian in the Irkutsk cluster is one of the most promising for increasing the hydrocarbon resource base in the assets of Rosneft Oil Company. Layer B1, related to bioherm structures, consistently shows high filtration-capacity properties of rocks, due to the conditions of formation. Zones of crushing and fracturing are noted, which have arisen as a result of destruction and karst formation of productive deposits. The results presented are based on the analysis of laboratory core studies. The principles of identifying lithological units of the B1 productive layer by structural and genetic characteristics, post-sedimentation transformations, which influenced the formation of deposits with high filtration-capacity properties, are considered. For the first time, a fundamental model of the formation of rocks of the B1 formation on the territory of the Irkutsk cluster is presented. According to the results of the core study by the structural-genetic character in the B1 formation, the following rock units were identified: dome-shaped stromatolites, columnar stromatolites with globulosa structure, columnar stromatolites with lineolata-globulosa structure, flat stromatolites with lineolata-globulosa structure, flat stromatolites with globulosa structure, granular, microphytolitic, detrital carbonate rocks. The performed studies allow, in the difficult geological conditions of Eastern Siberia, as well as with high heterogeneity of carbonate reservoirs, it is justified to perform hydrodynamic modeling, to plan the development of deposits, and place production wells. The proposed model of the B1 reservoir will make it possible to select the optimal development system with the most complete extraction of hydrocarbons with maximum economic profitability.
References
1. Reitner J., Queric N.-V., Arp G., Advances in stromatolite geobiology: Lecture notes in Earth Sciences, Heidelberg: Springer, Berlin, Heidelberg, 2011, 559 p., DOI:10.1007/978-3-642-10415-2
2. Chernitskiy A.V., Geologicheskoe modelirovanie neftyanykh zalezhey massivnogo tipa v karbonatnykh treshchinovatykh kollektorakh (Geological modeling of oil deposits of massive type in carbonate fractured reservoirs), Moscow: Publ. of RMNTK “Nefteotdacha”, 2002, 254 p.
3. Maslov V.P., Atlas porodoobrazuyushchikh organizmov (izvestkovykh i kremnevykh) (Atlas of rock-forming organisms (calcareous and silicic)), Moscow: Nauka Publ., 1979, 271 p.
4. Maslov V.P., Stromatolity ikh genezis, metod izucheniya, svyaz' s fatsiyami i geologicheskoe znachenie na primere ordovika Sibirskoy platformy (Stromatolites, their genesis, method of study, connection with facies and geological significance on the example of the Ordovician of the Siberian Platform), Moscow: Publ. of USSR AS, 1960, 233 p.
5. Fortunatova N.K. et al., Atlas strukturnykh komponentov karbonatnykh porod (Atlas of the structural components of carbonate rocks), Moscow: Publ. of VNIGNI, 2005, 440 p.
6. Titorenko T.N., Anisimova S.A., Anisimov A.Yu., Paleontologiya dokembriya. Fitolity (stromatolity i mikrofitolity) (Paleontology of the Precambrian. Phytoliths (stromatolites and microphytoliths)), Irkutsk: Publ. of ISU, 2012, 117 p.
