Parameters of the carbonate rocks of the oil deposits of 301, 302 and 303 of Romashkinskoye field were estimated on 69 core samples. Modelling of reservoir conditions during deposits development was carried out using IFES-1 facility (Republic of Bashkortostan, Oktyabrsky, VNIIGIS). We estimated true resistivity, P-wave velocity and the porosity before loading the sample and after load removal. Samples were placed in a chamber and the measurements were made under conditions close to the reservoir ones. Loading configuration intended constant confining pressure (rock pressure) and changes in pore (reservoir) pressure. At each stage of reservoir pressure changing it has been given a certain period (30 min) to complete the transition process. Two months after the measurement (after full restoration of elasto-mechanical properties) we determined gas permeability of samples again. Porosity of Vereckiann rocks was 3–20 %, of Bashkirian - 1.5–21 %, of Protvinskian – 0.2–23 %.
We considered two variants of the technology-related loading: soft and hard. In the soft mode pore (reservoir) pressure reduced from maximum (6.56–7.15 MPa) to an average value (2.24–4.0 MPa) and then restore to maximum. In the hard mode pressure reduced from maximum pore (reservoir) pressure to average value, decreased to minimum (1.0–0.2 MPa) and then restored to maximum.
We determined that rocks parameters had not significantly changed under soft mode of technology-related loading. Under hard mode of loading porosity decreased, true resistivity and P-wave velocity grew up.
Comparative analysis shows that for the majority of collector of the Vereiskian and Bashkirian productive horizons gas permeability is characterized by reduction of porosity. In case of Protvinskian high fractured rocks gas permeability increases sometimes.
1. Gubaydullin A.A., Musin K.M., Nurtdinova G.N. et al., Differentsiatsiya slozhnopostroennykh karbonatnykh kollektorov bashkirskogo yarusa po dannym analiza kerna (Differentiation of complex carbonate reservoirs of Bashkirian stage according core analysis), Proceedings of International conference, Kazan', 8–10 September 2003, pp. 609–612.
2. Gubaydullin F.A., Ibatullin R.R., Kandaurova G.F., Vliyanie tekhnogennykh faktorov i fiziko-khimicheskie metody vozdeystviya na kollektorskie svoystva karbonatnykh kollektorov (Influence of technogenic factors and physicochemical methods of influence on reservoir properties of carbonate reservoirs), Proceedings of International conference, Kazan', 8-10 September 2003, pp. 218–227.
3. Gubaidullin F., Gubaidullin A.A., Firsov S.V., Osipov P.V., Influence of physicochemical methods of influence on the filtration-capacitive properties of carbonate reservoir rocks (In Russ.), Proceedings of the XVII Mendeleev Congress on General and Applied Chemistry, Kazan, September 21–26, 2003.
4. Gubaydullin F. A., Krupin S.V., Firsov S.V., Development of the foundations for the regulation of the filtration characteristics of porous media with deteriorated reservoir properties during technological work to increase oil production (In Russ.), Proceedings of the XVII Mendeleev Congress on General and Applied Chemistry, Kazan, September 21–26, 2003.
5. Iktisanov V.A., Opredelenie fil'tratsionnykh parametrov plastov i reologicheskikh svoystv dispersnykh sistem pri razrabotke neftyanykh mestorozhdeniy (Determination of filtration parameters of reservoirs and rheological properties of disperse systems in the development of oil fields), Moscow: Publ. of VNIIOENG, 2001, 212 p.
6. Sitdikova L.M., Izotov V.G., Bruzhes L.N. et al., Material composition of the Upper Jurassic horizon of Tevlinsko-Russkinsky field (West Siberian oil and gas province) (In Russ.), Proceedings of International Multidisciplinary Scientific GeoConference, SGEM, 2016, V. 1, Book 1, pp. 369–376.
7. Kayukova G.P., Kosachev I.P., Plotnikova I.N. et al., Oil generation potential of the Permian deposits of Tatarstan based on the content, structure and thermal stability of organic matter in rocks (In Russ.), Proceedings of International Multidisciplinary Scientific GeoConference, SGEM, 2016, V. 1, Book 1, pp. 453–460.
8. Sidorova E.U., Sitdikova L.M., Izotov V.G., Onishchenko Y.V., Leading material complexes of the crystalline basement of the Tatar arch (East of the Russian plate) in the formation of weathering crust (In Russ.), Proceedings of International Multidisciplinary Scientific GeoConference, SGEM, 2016, V. 1, Book 1, pp. 321–328.
9. Mukhamatdinov I.I., Aliev F.A., Sitnov S.A. et al., Study of rheological behavior of systems ''polymer solution - rocks'' (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 11, pp. 121–123.
10. Runyan R.P., Nonparametric statistics: A contemporary approach, Massachusetts, USA: Addison-Wessley Publishing Company, 1977.