Paleotectonic reconstructions of formation conditions of gorskoye extra-heavy oil field

Abstract

The interest in hard-to-recover hydrocarbon reserves has recently increased significantly, which is primarily due to the need to maintain the level of oil production in the late stage of development. Since all relatively large oil fields in Republic of Tatarstan have been identified and developed, in the last decade, the process of exploration extra-heavy oil deposits, whose reserves are enormous, has been rapidly developing. The object of the study is extra-heavy oil reservoir of the Kamyshla Beds of the Kazanian Stage, confined to the Gorskoye field, located in the marginal part of the Eastern side of the Melekess depression, near its junction with the western slope of the South Tatar arch. At the same time, the location of the field within the outer side zone of the Ust-Cheremshan trough of the Kama-Kinel trough system pre-determined the significant influence of sedimentation processes on its for-mation. In order to establish the genesis, time of formation of the trap and Gorskoye extra-heavy oil deposit, the authors constructed a series of struc-tural maps, carried out studies by methods of isopachic triangle and graph of structure growth. Paleotectonic reconstructions of the studied territory at various stages of ontogenesis allowed us to establish that the core of the Gorsky structure is an organogenic structure of Late Frasnian age, the growth of which was resumed repeatedly until the Early Kazanian age. The formation of the Gorskoye extra-heavy deposit occurred in the Late Permian age, and as a result of tectonic movements of the Alpine stage of tectogen-esis, the deposit finally formed and began to collapse.