Gas separating intake for progressing cavity pumps
AssigneeBaker Hughes Incorporated
InventorBruce Erwin Proctor
Life of this patent
Estimating the term…
Abstract
A downhole pump assembly is suspended by tubing in a well. The pump assembly has a separator attached below a progressing cavity pump with a flexible shaft to accommodate the concentric path of the shaft of the separator and the eccentric path of the rotor of the pump. Vanes on the shaft of the separator use centrifugal force to separate the heavier liquids from the lighter gases in the well fluids. The separator discharges the gas into the casing and the liquid to the pump. A motor drives both the separator and the pump. A gear reduction unit is located between the motor and the pump in order to reduce the rotational speed from the motor to the desired rotational speed of the rotor for the pump.
Claims12
A system for pumping fluid from a well, comprising:
- a downhole progressing cavity pump;
- a downhole gas separator located below the pump for separating gas from liquid well fluid and delivering the liquid well fluid to the pump;
- a motor for supplying power to drive the downhole pump and the gas separator;
- a flexible shaft having an end coupled with a rotor from the pump which rotates in an elliptical orbit with the rotor, and an opposite end coupled with a separator shaft which rotates in a concentric orbit with the separator shaft, the flexible shaft allowing for elliptical movements of a rotor within the pump;
- a gear assembly between the motor and the pump, which reduces the speed that the rotor rotates within the pump to less than the speed of the motor;
- and
- a housing enclosing the flexible shaft having a portion sealingly mounted around the outer circumference of a portion of the gas separator and another portion sealingly mounted around the outer circumference of a portion of the pump, thereby defining an annular region for communicating fluids from the gas separator to the pump.
A system for pumping fluids, comprising:
- a downhole progressing cavity pump, adapted to be suspended on a string of tubing, and having a helical rotor rotated inside a stationary stator;
- a downhole separator located below the pump, having a housing and a vane that is rotatable within the housing;
- a downhole motor having a drive shaft extending therefrom for rotating the rotor of the pump and the vane of the gas separator;
- a flexible shaft assembly located between the rotor of the pump and the motor allowing for elliptical movements of a the rotor of the pump;
- and
- a gear reduction unit located between the motor and the rotor which makes the rotational speed of the rotor less than the rotational speed of the drive shaft of the motor.
A method for pumping well fluids comprising:
- (a) securing a gas separator having a rotary member to a progressing cavity pump, and suspending the progressing cavity pump and gas separator in a well;
- (b) supplying power to a motor to rotate a rotor of the progressing cavity pump and the rotary member;
- (c) rotating the rotary member at a speed higher than the rotor of the pump and separating gas from liquid of the well fluid in the gas separator;
- (d) flowing the liquids separated from the gas in the well fluid into the progressing cavity pump;
- then (e) pumping the liquids to the surface with the progressing cavity pump.
Dependencies are inferred from the claim text.