ELECTRICALLY DRIVEN BOREHOLE PUMP WITH WORKING FLUID CIRCULATION (VERSIONS) Russian patent published in 2014 - IPC E21B43/00 

FIELD: engines and pumps.

SUBSTANCE: invention relates to borehole pump systems to be immersed in bed fluid. Particularly, this invention relates to recirculation of flow portion fed by borehole pump of pump system to the inlet of the latter. Proposed system is mounted in the well and comprises bottom pump with discharge and intake sides, circulation coupling connected with bottom pump discharge side. This system comprises top pump with discharge side and intake side communicated with bottom pump intake side via circulation coupling. Besides, this system comprises drive motor connected under bottom pump to actuate both pumps. Channel to feed fluid in said pump system is communicated with bottom and top pump inlets. It includes driven shaft extending from drive motor via bottom pump, circulation coupling and top pump. Circulation line inlet is communicated with circulation coupling and discharge channel intended for discharge of fluid from circulation line at motor assembly side. Channel extending through circulation coupling and has bottom part converging along radius downward. The shaft extends through said channel to make ring chamber between said shaft and channel. Note here that circulation coupling configuration allows directing of fluid portion from bottom pump discharge side to top pump intake side while remainder fluid portion is fed to circulation line.

EFFECT: higher reliability.

13 cl, 5 dwg