Abstract: A downhole well pump has a housing with a housing bore having an upper section, a lower section and an intermediate section with a larger inner diameter than inner diameters of the upper and lower sections. A plunger has an upper plunger portion in the upper section of the housing bore, a piston in the intermediate section of the housing bore, and a lower plunger portion in the lower section of the housing bore. A hydraulic pump at the surface alternately supplies hydraulic fluid pressure to the upper and lower sides of the piston to cause the plunger to move upward and downward. A standing valve in the housing admits well fluid into the housing during the lifting stroke. A travelling valve moves in unison with the plunger for discharging well fluid from the housing during the lifting stroke.

Abstract: An electrical submersible pumping system (ESP) for pumping fluids from a wellbore is made of segments, which include a motor, a seal section, a pump, and a shaft assembly connected to an output of the motor drives the pump. The motor, seal section, and pump are elongate members and coupled end to end to one another by housing connectors and shaft connectors. At least one of the housing connectors and shaft connectors have portions that are pivotable with other portions, so that adjacent segments of the ESP system can pivot with respect to one another. The housing connector can be a ball and socket assembly, where the ball fits within a spherically shaped chamber in the socket assembly. Opposing ends of the housing connector can mount to respective segments by threads or bolt flanges. The pivotal shaft connector may be a universal joint.

Abstract: An electrical submersible pump assembly has modules including a pump, a motor, and a seal section. A drive shaft assembly extends from the motor through each of the modules. A threaded connection between at least two of the modules includes a first adapter having external threads and a second adapter having a neck with an external load shoulder. A collar is rotatably carried and axially movable on the neck. The collar has internal threads and an internal load shoulder. A shoulder ring having two segments encircles the neck. The shoulder ring has a first surface in abutment with the external load shoulder and a second surface in abutment with the internal load shoulder. A resilient ring tits around an outer diameter of the shoulder ring for retaining the ring segments on the neck prior to the collar being in threaded engagement with the threads of the first adapter.

Abstract: An electrical submersible pumping system (ESP) for pumping fluids from a wellbore is made of segments, which include a motor, a seal section, a pump, and a shaft assembly connected to an output of the motor drives the pump. The motor, seal section, and pump are elongate members and coupled end to end to one another by housing connectors and shaft connectors. At least one of the housing connectors and shaft connectors have portions that are pivotable with other portions, so that adjacent segments of the ESP system can pivot with respect to one another. The housing connector can be a ball and socket assembly, where the ball fits within a spherically shaped chamber in the socket assembly. Opposing ends of the housing connector can mount to respective segments by threads or bolt flanges. The pivotal shaft connector may be a universal joint.