WELL COMPLETION METHOD, EXPOSING PRODUCTIVE FORMATION, LOCATED IN ISOLATION FROM WATER-BEARING FORMATION Russian patent published in 2016 - IPC E21B43/11 E21B43/27 E21B43/22 E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: invention can be used for intensification of oil production from carbonate reservoirs. Method comprises selecting a productive formation, located in isolation from water-saturated formation. Opening thereof with a horizontal well far from water reservoir at a distance of more than 5 m from said formation. Running string of tubing string with starting clutches and with a funnel at its end. Funnel is placed in the range of the production string shoe. Flexible flush-joint pipe is lowered with a jet nozzle at end inside tubing string. Jet nozzle is introduced in horizontal uncased well and acid solution is placed at bottom hole, which is selected in volume equal to volume of annular space of well. Horizontal borehole is filled with aqueous solution of surfactant. Aqueous solution of surfactant is forced through flush-joint pipe into productive formation. At closed annular and tube space through annular space acid solution is flushed in well shaft, with flow rate providing for effect of water jet "cutting" rock, with stepped pressure rise and process exposure at each stage. Pressure from step to step is raised from 3 to 6 MPa. Process exposure at each stage is performed until pressure drops to 2 MPa. Well bore is washed, flexible flush-joint pipe is lifted from well, inert gas is pumped through annular space with extraction of liquid via tubing string. Killing fluid is pumped into well. Well is developed. Geophysical survey of horizontal shaft on flexible pipe is performed. “Inactive” intervals of horizontal shaft, having high permeability and porosity, are identified. Jet nozzle is installed at said intervals of horizontal shaft. Jet nozzle is directed at an angle to axis of horizontal shaft with thrust end of jet nozzle in wall of horizontal shaft. Acid solution circulates through flexible flush-joint pipe, jet nozzle and tubing string with creation of flow rate, providing effect of water jet "cutting" rock till recess in rock or channel and increase surface area exposure interval. Through annular space acid solution is flushed into formation. Soaking takes place so that acid solution could react with rock. Flexible flush-joint pipe with jet nozzle is lifted out of well. Inert gas is pumped through annular space with extraction of liquid via tubing string. Lifting speed is measured level of liquid in the well. Well is filled with killing fluid. Tubing string is lifted from well with starting clutches and funnel at its end. Downhole pumping equipment is lowered and the well in operation.

EFFECT: high efficiency of processing well.

1 cl, 1 ex