OIL WELL PUMP Russian patent published in 2004 - IPC

FIELD: oil and gas producing industry. SUBSTANCE: invention in designed for use in assemblies for testing of wells in process of drilling without lifting drill stem. Proposed oil well pump contains cylindrical housing and rod with through axial channel placed in housing, housing and rod being intercoupled by disconnectable clutch. Said clutch is made in form of cam clutch and is provided with hydraulic lock in form of two oil-filled chambers with radial holes in rod arranged between rod and housing, and tubular spool installed in axial channel of rod on shear pin and provided with groove to intercommunicate radial holes of rod, and seat for drop valve to close axial channel of rod. Relief bearing is placed between housing and rod. Working member of pump is double-acting ring piston forming working chambers with housing and rod, with intake and pressure channels accommodating, respectively, suction and delivery valves. Intake channels of working chambers communicate with annulus. Pump is furnished with mechanical to convert rotation of rod into reciprocation of piston in form of bushing with endless screw groove coupled with rod by means of splined connection, and guide engaging with said screw groove and installed in housing form reciprocating. Guide is coupled with piston. To change pump for liquid pumping out mode after finishing pf drilling at washing pf bottom hole, valve is dropped inside drill stem. Said valve seats on seat of tubular spool to close its axial channel. After building of gauge pressure in drill steam, cams of cam clutch disengage, and rod can rotate relative to housing, said rotation being converted into reciprocation of piston. At upwards and downwards movement of piston, liquid is sucked in from axial channel of rod into working chamber wherefrom it is delivered into annulus at change of direction of piston movement. Owing to the fact that axial channel of rod is free till the moment of change over of pump into pumping out mode, and clutch is engaged provides transmission of torque to drilling bit, proposed pump can be used in testing assemblies without lifting drill stem. EFFECT: enlarged operating capabilities. 2 cl, 5 dwg