FIELD: oil production.
SUBSTANCE: inventions group relates to oil production, in particular to downhole operations during the overhaul and current workover of wells, and can be used in operations of cleaning and restoring the bottom of wells. The method includes lowering into the well a device containing a screw downhole motor, a drilling tool and check valves. Next, the downhole motor is activated by supplying the working fluid under pressure through the internal cavities of the tubing and the device. When the first check valve is closed by the blocking element in the motor shaft channel, a direct circulation of the working fluid is created to the plug being drilled through the screw pair of the motor, the second check valve and the through hole of the drilling tool. The engine and the drilling tool are started. Next, the drilled plug is destroyed. Then, by supplying working fluid under pressure to the annulus, reverse circulation of the fluid with particles of the drilled plug is created to the wellhead through the internal cavities of the drilling tool, downhole motor shaft and tubing. Under the action of reverse circulation, the blocking element of the second check valve blocks the access of liquid to the screw pair of the downhole motor, and the blocking element of the first check valve opens the internal cavity of the downhole motor shaft for fluid flow through the tubing. Then the cycle of destruction and backwashing is repeated or the device is removed from the well.
EFFECT: well cleaning operation is optimized by eliminating the use of external influence when changing the direction of the circulating fluid, especially if it is necessary to repeatedly influence the plug within one trip.
4 cl, 3 dwg.
