OIL PRODUCTION METHOD AND DEVICE Russian patent published in 2008 - IPC E21B43/00 

FIELD: oil industry, particularly methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells.

SUBSTANCE: method involves installing downhole hydraulic piston motor of reciprocating type and downhole pump fixedly connected thereto in casing pipe by means of packer, wherein downhole pump is operated with the use of working fluid flow. Working fluid is circulated in closed loop to eliminate working fluid losses and to prevent mixing thereof with produced reservoir fluid. Reservoir fluid is supplied to well head through paired concentric flow string. Downhole hydraulic piston motor of reciprocating type is operated from well head. Device comprises downhole hydraulic piston motor of reciprocating type and downhole pump fixedly connected with each other and installed in casing pipe by means of packer. Downhole hydraulic piston motor and downhole pump are installed on paired concentric flow string having inner chamber isolated one from another with medium separation means. Hollow shaft passes through medium separation means. Hollow shaft communicates dowhhole pump with inner cavity of flow string having lesser diameter through inner channel. Downhole hydraulic piston motor of reciprocating type uses closed working fluid circulation loop to prevent working fluid mixing with produced reservoir fluid.

EFFECT: elimination of tubing string abrasion, simplified structure and decreased paraffin generation.

3 cl, 3 dwg