A fuel pump includes: an electric motor; a pump stage drivable by the electric motor; and a fuel pump housing configured to accommodate the electric motor and the pump stage. The fuel pump housing has a first housing part configured to accommodate the electric motor and a second housing part configured to accommodate the pump stage. One or both of the first housing part and the second housing part are made of a conductive plastic adapted to dissipate static charges to a ground potential.

A downhole drilling motor includes a motor housing having an inner bore and an outer surface. A power section includes a stator elastomer at least partially disposed within the inner bore of the motor housing. A bearing section includes an upper bearing at least partially disposed within the inner bore of the motor housing. The motor housing further includes an opening extending from the inner bore to the outer surface to provide a bypass fluid path for a fluid in the inner bore. The opening is disposed on the motor housing between a lower end of the stator elastomer and an upper end of the upper bearing. The bypass fluid path allows the downhole drilling motor to accommodate a higher flow rate of a fluid through the stator elastomer of the power section than through the upper bearing of the bearing section.

A device is provided for pumping fluid from a wellbore up to surface. The device includes a stator unit, a rotor unit run within the stator unit on a rod string, the rotor unit and the stator unit engaging with one another to form an annular space therebetween for passage of fluid. An upstream check valve on the rod string uphole of the rotor unit is moveable from an open position in which fluid is passable through the annular space, and a closed position in which fluid passage through the annular space is prevented. A hollow rod section extends through the rod string in fluid communication with the annular space both downstream and upstream of the upstream check valve, for entry of fluid into a downhole end of the hollow rod section, passage of fluid upstream therefrom and exit of fluids from an uphole end of the hollow rod section, back into the annular space. A method is further provided for pumping fluid from a wellbore after shutdown.

A flow-through assembly for use in a downhole drilling string includes a Moineau-type motor, means for selectively activating the motor such as a ball catch component that selectively causes drilling fluid to enter into or bypass the motor, and a rotating variable choke assembly that is driven by a rotor of the motor. The choke assembly varies the flow rate of drilling fluid as rotation causes ports of the choke assembly to enter into and out of alignment with each other. In one embodiment, the choke assembly comprises a faceted rotary component including bypass ports on the facets of the component. In another embodiment, the choke assembly comprises a tapered rotary component that rotates in a complementarily tapered stationary component.

One example of a gerotor pump includes an inner rotor comprising multiple teeth, the inner rotor configured to rotate about a first longitudinal gerotor pump axis. The gerotor pump also includes a hollow outer rotor including an outer surface and an inner surface having substantially identical contours, the inner surface configured to engage with the multiple teeth and to rotate about a second longitudinal gerotor pump axis. The pump includes a pump housing within which the inner rotor and the outer rotor are disposed, wherein the outer surface of the outer rotor defines gaps between the pump housing and the outer rotor.

A technique facilitates efficient well production in relatively low volume applications, e.g. applications after well pressure and volume taper off for a given well. According to an embodiment, use of an electric submersible progressive cavity pump is enabled in harsh, high temperature downhole environments. A pump stator facilitates long-term use in such harsh environments by providing a composite structure having an outer housing and a thermoset resin layer located within the outer housing and secured to the outer housing. The thermoset resin layer is constructed with an internal surface having an internal thread design. Additionally, an elastomeric layer is located within the thermoset resin layer and has a shape which follows the internal thread. In this manner, the elastomeric layer is able to provide an interior surface generally matching the shape of the internal thread of the thermoset resin layer and arranged for interaction with a corresponding pump rotor.

A method for controlling a permanent magnet (PM) synchronous motor in an ESP application is provided. A load angle of the PM motor is estimated. A voltage adjustment value is determined for the PM motor based at least on the estimated load angle of the PM motor. A voltage to be applied to the PM motor is determined based on the voltage adjustment value.

A fluid pump includes a pump element in communication with an inlet and an outlet. Rotation of the pump element generates a suction at the inlet and pressure at the outlet. The suction and pressure cooperate to move a fluid through a fluid path. An accessory fluid path is in communication with the inlet and outlet. The accessory fluid path includes a thermistor in communication with the accessory fluid path. The thermistor monitors a temperature of the fluid within the accessory fluid path.

A method for controlling a permanent magnet (PM) synchronous motor in an ESP application is provided. A load angle of the PM motor is estimated. A voltage adjustment value is determined for the PM motor based at least on the estimated load angle of the PM motor. A voltage to be applied to the PM motor is determined based on the voltage adjustment value.

A stator for use in a positive displacement motor or a progressing cavity pump. The stator comprises an elastomer mix preferably including rubber and a fiber reinforcement. The fiber reinforcement includes a plurality of fibers. The elastomer mix is formed into a stator via an injection molding process. The injection molding process includes a shear flow step in which shear flow is induced in the elastomer mix while the elastomer mix is in an uncured state. The shear flow modifies the orientation of the fibers into an advantageous modified fiber orientation. Shear flow is induced preferably via differential rotation of injection mold assembly elements during the injection molding process. Methods of manufacturing the stator are also disclosed.