OIL FORMATION TREATMENT METHOD Russian patent published in 2007 - IPC E21B43/16 

FIELD: oil extractive industry, namely, methods for processing heterogeneous oil deposits with usage of adjustment of filtration flow directions and increase of washing properties of agent being forced in.

SUBSTANCE: method includes successive forcing of gas and buffers of water-gas mixture through two force wells. Forcing is performed in two stages. At first stage, gas is simultaneously forced into both force wells until beginning of stable increase of gas factor of at least one extractive well of stock. At second stage, cyclic alternating forcing of buffers of water-gas mixture is performed, while each cycle is started with forcing in of buffer, consisting of water with surfactant and gas, with gas content 2-3 times exceeding gas content of mixture of basic-optimal composition, into force well with greater pickup, and buffer, consisting of water and gas, with base gas content of 25% in thermobaric conditions of deposit being studied, into force well with lesser pickup. After that water buffers are forced into force wells in volumes, equal to 5% of volume of pores of treatment area of each well. Force well for forcing in buffer of mixture with greater gas content and force well for forcing in a buffer of mixture with lesser gas content are selected when forcing in the water buffer. Used as surfactant are nonionic surfactants of ОН-10 and АФ9-12 types with content of water-gas mixture in water phase being forced in ranging from 0,1 to 5% of mass %.

EFFECT: increased oil recovery due to increased coefficients of displacement and area of effect of displacement.

2 cl, 1 ex