Theoretical features of improving the oil recovery efficiency from carbonate reservoirs in the Volga-Ural province

Abstract

Currently, the share of hard-to-recover oil reserves confined to carbonate reservoirs is more than 20% of the Volga-Urals hydrocarbon reserves. The use of traditional acid stimulation in conditions of a complex structure of carbonate reservoirs and low reservoir pressure is ineffective. In order to increase the efficiency of hydrochloric acid treatment, theoretical and experimental studies have been carried out aimed at increasing the efficiency of the work being carried out to stimulate the inflow to production wells that operate carbonate reservoirs. Filtration of the acid solution into low-permeability intervals of the carbonate reservoir involves the use of reverse counter-current capillary impregnation mechanisms. Analytical research methods made it possible to determine that the activation of the impregnation processes is carried out under conditions of nonstationarity of the pressure parameters of the reservoir system. Numerical modeling of the exposure process allowed to optimize the exposure parameters.

Tectonic aspects of super-viscous oil deposits formation and placement within the Volga-Ural anteclise

“…In accordance with existing ideas [1][2][3][4][5], the beginning of the platform stage of the anteclise development is corresponded to the Vendian. It includes the following four tectonic cycles: Baikalian, Caledonian, Hercynian and Alpine, each of which is divided into separate stages corresponding to the times of new structural level reconstruction.…”