DEVICE FOR RESTORATION OF PRODUCTIVITY OF PRODUCING WELLS AND INJECTIVITY OF INJECTION WELLS Russian patent published in 2002 - IPC

FIELD: oil producing industry. SUBSTANCE: device includes a tubing string with a removable choke suspended from hoisting mechanism traveling system. Pumping-out unit of reciprocating action has a movable member with pressure valve connected to lower part of tubing string. Fixed member of suction valve of pumping-out unit is located in upper part of liner. Liner lower part has inlet holes. Stop limits motion of the movable member of pumping-out unit with respect to fixed member. A limiter of down motion of the movable member is placed in liner lower part. Device has a packer, plug, rod which are located on liner between inlet holes and fixed member of pumping-out unit. Liner in points of location of the packer and plug with the rod has a sealed telescopic connection with shear pins and possibility of limited axial motion in which the rod is engageable with the plug and packer assumes working position. A pusher is located above the suction valve and rigidly connected to it with its base and is engageable with the pressure valve in lower point of motion of the movable member of the pumping-out unit. The plug is installed on the liner below its inlet holes. The movable member of the pumping-out unit is made in the form of a cylinder with a case, and fixed member is made in the form of a piston. The device may be provided with a sand valve installed in the tubing string between a removable choke and the movable member of the pumping-out unit and may have gas-discharge holes on the liner located under the packer. EFFECT: higher efficiency of treatment of bottom-hole formation zone and prolonged service life of device. 3 cl, 1 dwg, 1 ex