The article presents the results of research on a number of post-sedimentation factors affecting the conversion of organic matter. Taking into account the additional tectonic impact on oil-producing rocks in the future will expand the boundaries of ideas about the oil and gas potential of some regions, as well as increase the volume of the Rosneft Сompany's resource base within its license areas and a number of territories of the Unallocated Fund of the Russian Federation. The authors explore the issues of the level of oil and gas formation and the degree of carbonification of dispersed organic matter using the example of the identified oil and gas content of the Preddonetsky trough and southern Sakhalin, and the features of the phase composition of hydrocarbons in open fields. The results can be used to assess the prospects for oil and gas discovery in areas initially classified as unpromising due to insufficient catagenetic maturity of parent rocks. In addition to the main and traditional factors of transformation of organic matter of sedimentary strata (temperature, pressure, and geological time), the influence of local dynamic stresses, compression energy, and local warming of rocks due to the influence of fault tectonics is considered. The existing volume of actual and experimental data indicates an increase in the stage of catagenesis in the zones of active tectonic dislocations, which is evident in the local increase in the reflectivity of vitrinite of coal inclusions.
Within the North-Donetsk trough and small intermountain depressions of southern Sakhalin, where the estimated oil and gas potential is quite limited, fault tectonics and heat and mass transfer of substances can become increasingly important and could influence the formation of local promising zones for the search for oil and/or gas accumulations. One of the factors indicating the possible influence of dynamic action in natural conditions (dynamocatagenesis) is an uneven catagenesis within large structural objects. In particular, increased catagenetic transformation is recorded in zones bordering on folded structures, and local manifestations of additional stress on generating strata are observed.
References
1. Gladenkov Yu.B., Bazhenova O.K., Grechin V.I. et al., Kaynozoy Sakhalina i ego neftegazonosnost' (Cenozoic of Sakhalin and its oil and gas potential), Moscow: Geos Publ., 2002, 226 p.
2. Kharakhinov V.V., Neftegazovaya geologiya Sakhalinskogo regiona (Petroleum geology of the Sakhalin region), Moscow: Nauchnyy mir Publ., 2010, 276 p.
3. Astakhov M.S., Melenevskiy V.N., Fomin A.N., Vliyanie raznomasshtabnykh tektonicheskikh dislokatsiy na preobrazovanie organicheskogo veshchestva ugley (Influence of different-scale tectonic dislocations on the transformation of organic matter in coal), Proceedings of 12th International Scientific and Practical Conference “Geomodel' – 2017”, Gelendzhik, 11 – 14 September 2017, 11 p.
4. Cherskiy N.V., Tsarev V.P., Soroko T.I., Kuznetsov O.L., Vliyanie tektono-seysmicheskikh protsessov na obrazovanie i nakoplenie uglevodorodov (Influence of tectonic-seismic processes on the formation and accumulation of hydrocarbons): edited by Trofimuk A.A., Novosibirsk: Nauka Publ., 1985, 224 p.
5. Lobusev A.V., Martynov V.G., Strakhov P.N., Novoe napravlenie k podkhodu podscheta zapasov nefti i gaza (A new direction to the approach to estimating oil and gas reserves), Proceedings of Gubkin University, 2011, no. 4, pp. 75–88.
