Methods and apparatus for utilizing a valve with a pump rotor passage with a downhole production string, the pump rotor being on a rotatable rod with a bobbin moving along the rod between a position for opening the passage to fluid flow, when the bobbin is not seated on a shuttle seat, and a position for closing the passage to fluid flow, when the bobbin is seated on the shuttle seat. The pump rotor and rod are removable through the passage while leaving the pump stator in place upstream of the valve.

A suction cover for a reciprocating pump assembly includes a plug configured to be at least partially received within an access port of a fluid cylinder of the reciprocating pump assembly. The plug includes at least one key configured to be received through a keyhole of the access port such that the at least one key extends within a keyway of the access port when the plug is at least partially received within the access port. The plug is configured to be rotated within the access port between an unlocked position wherein the at least one key is aligned with the keyhole and a locked position that prevents the plug from backing out of the access port.

The disclosure provides a formation fluid pumping method and pump, and a wellbore system that in one example includes wellbore surface equipment connected to a downhole tool including a formation fluid container having a fluid input port and a fluid output port, and a moveable piston inside the formation fluid container having two fluid chambers positioned to alternately pump a quantity of formation fluid in the formation fluid container from the fluid input port to the fluid output port. The wellbore system further includes a mechanical piston actuator having a rotary portion attached to the formation fluid container and a linear portion attached to the moveable piston, and a brushless direct current motor coupled to the rotary portion of the mechanical piston actuator and controlled to alternately rotate the rotary portion of the mechanical piston actuator in opposite directions to pump the quantity of formation fluid.

Systems and methods for monitoring, detecting, and/or intervening with respect to cavitation and pulsation events during hydraulic fracturing operations may include a supervisory controller. The supervisory controller may be configured to receive pump signals indicative of one or more of pump discharge pressure, pump suction pressure, pump speed, or pump vibration associated with operation of the hydraulic fracturing pump. The supervisory controller also may be configured to receive blender signals indicative of one or more of blender flow rate or blender discharge pressure. Based on one or more of these signals, the supervisory controller may be configured to detect a cavitation event and/or a pulsation event. The supervisory controller may be configured to generate a cavitation notification signal indicative of detection of cavitation associated with operation of the hydraulic fracturing pump, and/or a pulsation notification signal indicative of detection of pulsation associated with operation of the hydraulic fracturing pump.

An apparatus according to which a power end of a reciprocating pump assembly includes a block having bores formed therethrough, and crossheads disposed in the bores and adapted to reciprocate therein. A lubrication pump is in fluid communication with the bores. The pump is operable to pump lubrication fluid into each of the bores so that the crossheads are lubricated as they reciprocate within their respective bores. In another aspect, a power end includes a crosshead block and a power frame connected thereto, the frame including rib plates and supporting the crosshead block. In yet another aspect, a method includes casting a crosshead block; fabricating rib plates; connecting the rib plates to form a frame; and connecting the cast crosshead block to the frame. In some embodiments, the power ends may be used in oilfield operations such as, for example, the cementing, acidizing, or fracturing of a subterranean wellbore.

An apparatus according to which a power end of a reciprocating pump assembly includes a block having bores formed therethrough, and crossheads disposed in the bores and adapted to reciprocate therein. A lubrication pump is in fluid communication with the bores. The pump is operable to pump lubrication fluid into each of the bores so that the crossheads are lubricated as they reciprocate within their respective bores. In another aspect, a power end includes a crosshead block and a power frame connected thereto, the frame including rib plates and supporting the crosshead block. In yet another aspect, a method includes casting a crosshead block; fabricating rib plates; connecting the rib plates to form a frame; and connecting the cast crosshead block to the frame. In some embodiments, the power ends may be used in oilfield operations such as, for example, the cementing, acidizing, or fracturing of a subterranean wellbore.

A power end assembly includes a crankshaft section, a crosshead section, and a connector section coupled together by one, two, or more sets of stay rods. The power end may include one or more support plates that are coupled to the crankshaft section and/or crosshead section. The crosshead section includes a plurality of individual crosshead frames. The connector section may include a plurality of individual connector plates or may be a unitary connector plate. The power end is configured to be coupled to a fluid end assembly by coupling the fluid end assembly to the connector plates.

Methods for operating a decoupled long stroke pump to pump treatment fluid to a wellbore are provided. The decoupled long stroke pump has relatively long stroke plungers that can be powered by hydraulics, linear electric motors, mechanical long stroke mechanisms, linear actuators, or any other device that can provide a linear force to the plungers. Such long stroke pumps have the suction and discharge strokes decoupled such that an absolute linear flow rate without pressure pulses on the suction or discharge can be produced. Any desired flow profile of the treatment fluid can be produced via the decoupled long stroke pump.

A system and method for controlling a pump in a drilling system, of which the method includes determining a plurality of baseline behaviors for one or more valves of the pump, determining a plurality of in-use behaviors for the one or more valves of the pump. Each of the plurality of in-use behaviors are determined based on one or more measurements from one or more sensors. The method also includes comparing the in-use behaviors and the baseline behaviors, and forecasting, based on the comparison of the in-use behaviors and the baseline behaviors, a remaining useful life of the at least one of the one or more valves.

Methods and apparatus for utilizing a valve with a pump rotor passage with a downhole production string, the pump rotor being on a rotatable rod with a bobbin moving along the rod between a position for opening the passage to fluid flow, when the bobbin is not seated on a shuttle seat, and a position for closing the passage to fluid flow, when the bobbin is seated on the shuttle seat. The pump rotor and rod are removable through the passage while leaving the pump stator in place upstream of the valve.