CYCLIC METHOD FOR OIL RESERVOIR DEVELOPMENT Russian patent published in 2007 - IPC E21B43/20 

FIELD: enhanced recovery methods for obtaining hydrocarbons, particularly to develop oil-gas-water reservoirs beginning from any hydrocarbon production stage.

SUBSTANCE: cyclic method involves executing several cycles, wherein each cycle includes reservoir energy depletion regime at which product is extracted by means of production wells, and forced energy increase regime at which water is injected in productive reservoir through injection wells to recover liquid volume and energy in the reservoir. Product extraction in reservoir energy depletion regime is carried out with predetermined degree of water content in each cycle, namely with 30-95%, wherein the water content degree is obtained by reservoir drawdown rate exceeding critical one and corresponding to water-free oil production, as well as for a time before oil output reduction beginning. Duration of forced energy increase regime is equal or shorter than that of reservoir energy depletion regime so that injected water volume does not exceed produced liquid volume and volumetric water injection rate in productive reservoir, which leads hydraulic fracturing thereof.

EFFECT: increased oil recovery stage and prevention of oil reservoir separation.

6 cl, 1 dwg