In accordance with at least one aspect of this disclosure, a variable displacement pump system can include, a variable displacement pump disposed in a main line and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump is disposed in the main line between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.

A wellbore pumping system (10) has at least one jet pump (18, 20) disposed in a tubular string (12) inserted into a subsurface wellbore (II). An intake of the jet pump is in fluid communication with a subsurface reservoir. A discharge of the jet pump is in fluid communication with an interior of a tubular string extending to the surface. A fluid bypass (24, 26) fluidly connects the inlet and discharge of the jet pump. The fluid bypass in some embodiments is operable to enable fluid flow when a differential pressure of fluid pumped into the tubular string from the surface exceeds a predetermined pressure. Another aspect includes a pump system having two separately operable jet pumps in tandem in a wellbore tubular string.

A discharge valve assembly configured to control fluid flow out of a chamber of a pump fluid end of a pump, wherein the discharge valve assembly comprises a controllable holding system (CHS), wherein the CHS is controllable to hold the discharge valve assembly in an open configuration.

The present invention relates to a liquid metering device (1) for metering pumps which is formed by a main longitudinal conduit (2) with a first and second opposite ends (2.1, 2.2) comprising a fluid inlet (3) at the first end (2.1) located perpendicular thereto, a first outlet (4) at the second end (2.2), and a first connection (5) to backpressure control means (6), a second connection (7) to safety means (8), acting in parallel and in an independent manner, and a second overpressure outlet (9), arranged in one and the same connecting section (10), and where said connecting section (10) has an inclined wall (11) allowing the fluid to exit through the first outlet (4) for a fluid pressure equal to or greater than a fixed backpressure value and the fluid to exit through the second outlet (9) for a pressure greater than a fixed value.

The present invention relates to a liquid metering device (1) for metering pumps which is formed by a main longitudinal conduit (2) with a first and second opposite ends (2.1, 2.2) comprising a fluid inlet (3) at the first end (2.1) located perpendicular thereto, a first outlet (4) at the second end (2.2), and a first connection (5) to backpressure control means (6), a second connection (7) to safety means (8), acting in parallel and in an independent manner, and a second overpressure outlet (9), arranged in one and the same connecting section (10), and where said connecting section (10) has an inclined wall (11) allowing the fluid to exit through the first outlet (4) for a fluid pressure equal to or greater than a fixed backpressure value and the fluid to exit through the second outlet (9) for a pressure greater than a fixed value.

A wellbore pumping system (10) has at least one jet pump (18, 20) disposed in a tubular string (12) inserted into a subsurface wellbore (II). An intake of the jet pump is in fluid communication with a subsurface reservoir. A discharge of the jet pump is in fluid communication with an interior of a tubular string extending to the surface. A fluid bypass (24, 26) fluidly connects the inlet and discharge of the jet pump. The fluid bypass in some embodiments is operable to enable fluid flow when a differential pressure of fluid pumped into the tubular string from the surface exceeds a predetermined pressure. Another aspect includes a pump system having two separately operable jet pumps in tandem in a wellbore tubular string.

A hydraulic system that has a hydraulic pump connected to and in communication with a hydraulic motor, at least one hydraulic cylinder, or both by a first conduit and a second conduit (i.e., a high side and a low side). The hydraulic system has a bypass valve connected to and in communication with the first conduit and the second conduit. The bypass valve has a preset pressure that is above a minimum low side pressure. When a shock load occurs in the hydraulic system and a related drop in pressure on the low side occurs, the bypass valve opens when the preset pressure is passed thereby preventing the pressure from dropping to the minimum low side pressure. The hydraulic system thereby avoids a low loop event that could cause damage to the hydraulic system without the presence of larger charge pumps or accumulators.

A reciprocating low-speed heavy-load hydraulic pump with a variable action area comprises a plurality of hydraulic cylinder units (3) and moving members (1, 2). Two ends of the hydraulic cylinder units (3) are separately connected with the moving members (1, 2) via mechanical structures. The moving members (1, 2) move relative to each other. The hydraulic cylinder unit (3) consists of a hydraulic cylinder (4), a reversing valve (5) and a one-way valve (6). The hydraulic cylinder (4), the reversing valve (5) and the one-way valve (6) are connected with each other via hydraulic pipelines. Based on different magnitudes of driving force, the hydraulic pump can proactively configure and form different combinations of hydraulic cylinder units, and further adjust the size of an equivalent action area. Therefore, even if the magnitude of the driving force changes, it can be ensured that the hydraulic pump consisting of hydraulic cylinder units outputs oil liquid with a relatively stable pressure for use by a subsequently connected system. The reciprocating low-speed heavy-load hydraulic pump with a variable action area is advantageous in high conversion efficiency, a simple system structure and good working stability.

A system includes a variable displacement pump (VDP) in fluid communication with an inlet line and with an outlet line. The VDP includes a variable displacement mechanism configured to vary pressure to the outlet line. A bypass valve (BPV) includes a BPV inlet in fluid communication with the outlet line, and a BPV outlet in fluid communication with a bypass line that feeds into the inlet line upstream of the VDP. A minimum pressure shutoff valve (MPSOV) is connected in fluid communication with the outlet line, configured to block flow through the outlet line for shutoff. The MPSOV is connected in fluid communication with the BPV for triggering recirculation through the BPV.

In accordance with at least one aspect of this disclosure, a variable displacement pump system can include, a variable displacement pump disposed in a main line and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump is disposed in the main line between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.