Downhole circulation pump.

摘要

A positive displacement pump for circulating fluids downhole comprises a rotor (70) which transmits torque from an upper drill string section to a tool (l9) attached to the lower end of the pump via a connecting means (52). Bow springs (90) prevent a stator portion (32) of the pump from rotating in the wellbore. Fluid is counterflowed up the interior of the drill string by the positive displacement pump through a check valve (l2) into a settling chamber (l4). Cuttings or other solids settle out of the fluid and the fluid is then pumped out through one or more discharge ports to the lowermost end of the drill string.