No abstract

Currently, the use of gas methods to increase oil recovery is underexplored. However, the experience of applying these methods, both in Russia and abroad, indicates their high technological and economic efficiency. The article takes the first step towards substantiating the use of gas methods in the conditions of operational facilities in Bashkortostan. The goal of the research was to carry out a forecast of the results of gas exposure on hard-to-recover and residual oil reserves in Bashkortostan fields. The objectives of the research were the creation and adaptation of mathematical models of oil displacement for the conditions of productive objects and the fulfillment of the forecast for an increase in the production of residual oil reserves in the fields. The studies were carried out using models of filtering processes of multicomponent mixtures, a three-dimensional formulation of the problem and complex boundary conditions of polygon objects. The completeness of the generation of residual reserves was calculated. As a result of the research, a mathematical model of gas exposure to hard-torecover and residual oil reserves was adapted to the geological and field conditions of the Volga-Urals, which allowed for a reduction in the volume of calculations. The article presents the results of mathematical modeling of the process of displacing oil from the porous medium of the reservoir rocks of the fields of the Republic of Bashkortostan through the use of gas exposure.

Justification of the effective chemical methods and technologies for oil production increase of highly rugged low-productive reservoirs is a relevant area of focus. The primary objective in this area is to justify the selection and planning of technologies of injection of chemical agents for field-geological factors of Tyumen deposits. Tyumen deposits are characterized by a high degree of heterogeneity of the structure and are represented by irregularly discontinuous interlensing of sandstones, aleurolites, clays and coals. High internal heterogeneity of the reservoir determines abnormally low permeability (on the average less than 6 mD) and weak pressure communication in the bed. Due to the complex geological structure there has been an intensive production decline, decreasing of injectivity and initially high water cut of production during well operation. In order to increase the production stimulation and injectivity at the operating wells, more than 50 exposure technologies have been tested. The main scope of work on wells with injectivity less than 120 m3/day is performed by injection of surfactant-containing and emulsion formulations. Factors determining the efficiency of applied technologies in Tyumen deposits were studied. It is necessary not only to consider and compare the achieved efficiency of certain technologies, but also to continue searching for new chemical formulations to increase oil production of highly-rugged low-productive reservoirs. The paper presented an algorithm for analyzing the results of operations conducted at the injection wells.

The article substantiates the conditions for effective water and gas impact on productive formations of the Upper Jurassic and Achimov deposits of the Vyintoy oil field: for the UJ formation, alternate injection of “wet” gas and water (gas injection for 3 months – water injection for 3 months) with a maximum intake capacity of gas injection wells of 15 thousand m3 per day with a total volume of gas agent injection of 20 % of the pore formation volume; for the Ach formation, continuous injection of “wet” gas with a maximum intake capacity of gas injection wells of 30 thousand m3 per day.