METHOD OF DEVELOPMENT OF LOW-PERMEABLE OIL DEPOSITS Russian patent published in 2018 - IPC E21B43/16 E21B43/26 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil field development, in particular, to oil production in low-permeability reservoirs. According to the method, a directional and/or horizontal well system is drilled. Offshoots are perforated. Formation is multiply hydraulically fractured to form a system of cracks. Proppant is pumped into the formed system of cracks through injection and exploitation wells. Oxygen-containing agent is then pumped through injection wells to create a high temperature oxidation zone. Wherein before injection of the oxygen-containing agent through injection wells, a rim in form of a condensate wide spread of light hydrocarbons containing at least 80 % of light hydrocarbons from C3 to C6 inclusive is pumped. After injection of said rim, the injection wells are washed with nitrogen in a volume of at least 2.5 volumes of the borehole to remove light hydrocarbons. Mixture of oxygen and nitrogen with an oxygen concentration of 10–40 mol.% is used as the oxygen-containing agent. Volumes of the oxygen-containing agent and the rim in form of a condensate wide spread of light hydrocarbons are selected according to the condition of maximum mixability of the system consisting of oil-in-place, light hydrocarbons and inert gas – a product of in-situ transformation of the oxygen-containing agent.

EFFECT: oil recovery is increased due to the decreased filtration resistance to fluid movement.

1 cl, 6 dwg