METHOD FOR LOW-PERMEABLE PRODUCTIVE FORMATION TREATMENT Russian patent published in 2006 - IPC E21B43/16 E21B43/27 

FIELD: oil field development, particularly to stimulate oil production from low-permeable formation by formation treatment with acid.

SUBSTANCE: method involves lowering flow string provided with hydraulic pulsator in well so that flow string reaches productive formation zone; injecting calculated volume of acid in well via the flow string; forcing acid in productive formation to be treated under pressure; creating hydraulic pulses with the use of hydraulic pulsator and flushing well. Before flow string provided with hydraulic pulsator lowering in well orifice is created in pulsator wall. Check valve is installed in the orifice so that the check valve may be opened from flow string interior to provide acid injection in well. Then flow string is lowered in well up to productive formation bottom. After acid injection flow string and hydraulic pulsator are lifted to acid column top and reverse liquid circulation is performed with the use of the same pump along with pressure application to acid column. Acid is simultaneously subjected to hydraulic pulse application. Formation injectivity is controlled along with continuous circulation performing. Acid penetration intensity may be estimated from circulation liquid rate reduction in displacement tank of the pump.

EFFECT: increased efficiency of formation treatment and increased oil production from well.

3 cl, 2 dwg