METHOD OF INCREASING OIL RECOVERY AT FACILITIES WITH FORMED FORMATION PRESSURE MAINTENANCE SYSTEM Russian patent published in 2024 - IPC E21B43/16 

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry, in particular to the field of development of oil deposits at a later stage of development, and can be used in development of oil deposits with terrigenous reservoir, separated by clay impermeable or clay-covered low-permeable bridge. Method of increasing oil recovery at facilities with a formed formation pressure maintenance system, opened by injection wells and at least two production wells, includes determining filtration-capacitive characteristics of productive formations, pumping of working agent through injection wells and extraction of liquid through production wells. Additionally, residual recoverable oil reserves are determined for the deposit section and the compartmentalization factor for the production facility; at the later stage of development, the deposit section drilled according to the design grid of wells is selected, where withdrawals are carried out by means of mechanized production from production wells with residual recoverable oil reserves in the deposit section of not less than 3,000 t with extraction of recoverable reserves of not more than 90%, average value of the compartmentalization factor for the production section of the deposit is not less than 1.25, the average formation pressure on the producers is less than 0.7 of the initial formation pressure in the section of the deposit, the average porosity of the productive deposits for the wells is from 0.12 to 0.26, with absolute permeability of productive interlayers, differing by more than 1.2 times, type of injected water – water of surface water sources with mineralization from 0.2 to 285 g/l, bottomhole pressure in injection wells is increased by at least 1.2 times from the average value of bottomhole pressure for the last month until formation pressure in the deposit area increases by 20 to 80% for 1-6 months, but not more than by 20% from initial formation pressure at deposit section, then, depression is increased in the bottomhole zone of producing wells by reducing bottomhole pressure to 40-50 atm for terrigenous Devonian and to 20-30 atm for terrigenous Carboniferous. Residual oil pillars, lenses, dead-end and stagnant zones, low-permeability interlayers are involved in development in non-uniform flooded formations by bringing the site into the above-mentioned operating mode, oil recovery is increased.

EFFECT: this method is a powerful stimulus for intensification of oil production and increase in oil recovery.

1 cl, 3 ex