CN108700059A - Rotary hydraulic pump with ESP motor - Google Patents

Abstract

A submersible pumping system (100) includes an electric motor (110) and a pump (108) driven by the electric motor. The pump (108) includes a rotatable shaft (122) driven by a motor, one or more piston assemblies (132) configured for linear reciprocating motion, and a mechanism for converting rotational movement of the shaft into linear reciprocating movement in the piston assemblies. In one aspect, the mechanism for translating rotational movement of the shaft includes a tilt disk assembly (134). In another aspect, the mechanism for translating rotational movement of the shaft includes a camshaft assembly.

Description

Rotary hydraulic pump with ESP motor

technical field

The present invention relates generally to the field of submersible pumping systems, and more particularly, but not exclusively, to rotary hydraulic pumps driven by submersible electric motors.

Background technique

Submersible pumping systems are frequently deployed in wells to recover petroleum fluids from subterranean reservoirs. Typically, a submersible pumping system includes a number of components including an electric motor coupled to one or more centrifugal pump assemblies. The production tubing is connected to the pump assembly to transport petroleum fluids from the subterranean reservoir to the above-ground storage facility. Pump assemblies often employ axially and centrifugally oriented multistage turbines.

However, in certain applications, the volume of fluid available to be produced from the well is insufficient to support the costs associated with conventional electrically powered submersible pumping systems. In the past, alternative lift systems were used to encourage production from "edge" wells. Surface-based sucker rod pumps and air driven plunger lift systems are used in small volume wells. Although widely adopted, these solutions may not be acceptable or desirable for a number of reasons. Therefore, a need exists for an improved submersible pumping system that is well suited for use in marginal wells.

Contents of the invention

In some embodiments, the invention includes a submersible pumping system having an electric motor and a pump driven by the electric motor. The pump includes a rotatable shaft driven by a motor, one or more piston assemblies configured for linear reciprocating motion, and means for converting rotational movement of the shaft into linear reciprocating motion in the piston assemblies.

In another aspect, embodiments of the invention include a pump that can be used within a submersible pumping system. The pump includes a cylinder block including a plurality of cylinders, a rotatable shaft, a swash plate assembly, and a plurality of piston assemblies. The swash plate assembly includes a drive plate connected to the rotatable shaft and configured to rotate with the shaft, and a rocker plate not configured to rotate with the shaft. Each of the plurality of piston assemblies includes a plunger configured for reciprocating linear movement in a corresponding one of the plurality of cylinders, and a piston rod connected to the plunger and the rocker plate.

In yet another aspect, embodiments of the invention include a pump usable within a submersible pumping system. A pump includes multiple manifolds and one or more cylinder banks. Each of the cylinder banks corresponds to a separate one of the plurality of manifolds. The pump also includes a plurality of cylinders within each of the cylinder banks, and each cylinder is in fluid communication with a corresponding manifold. The pump also includes a rotatable camshaft and multiple piston assemblies. Each piston assembly includes a piston and a connecting rod connecting the piston to the camshaft.

Description of drawings

Figure 1 depicts a submersible pumping system constructed in accordance with an embodiment of the present invention.

2 provides a cross-sectional view of the rotary hydraulic pump of the pumping system of FIG. 1 constructed in accordance with an embodiment.

FIG. 3 is a view of a downstream side of a cylinder block of the rotary hydraulic pump of FIG. 2 .

FIG. 4 is a view of an upstream side of a cylinder block of the rotary hydraulic pump of FIG. 2 .

Fig. 5 is a view of the downstream side of the inclined plate of the rotary hydraulic pump of Fig. 2 .

FIG. 6 is a view of the downstream side of the driver of the rotary hydraulic pump of FIG. 2 .

Figure 7 provides a cross-sectional view of a rotary hydraulic pump constructed in accordance with an alternative embodiment.

8 provides a side cross-sectional view of the rotary hydraulic pump of the pumping system of FIG. 1 constructed in accordance with an alternative embodiment.

FIG. 9 provides a top cross-sectional view of the rotary hydraulic pump of FIG. 8 .

Detailed ways

Figure 1 shows an elevational view of a pumping system 100 attached to a production tubing 102, according to an exemplary embodiment of the invention. The pumping system 100 and production tubing 102 are disposed in a well 104 drilled for the production of fluids such as water or oil. As used herein, the term "petroleum" refers broadly to all mineral hydrocarbons, such as crude oil, gas, and combinations of oil and gas. A production tubing 102 connects the pumping system 100 to a wellhead 106 located at the surface.

Pumping system 100 includes pump 108 , motor 110 and seal section 112 . Although the pumping system 100 is primarily designed to pump petroleum products, it will be appreciated that the present invention can also be used to move other fluids. It will also be appreciated that although each of the components of pumping system 100 are primarily disclosed in submersible applications, some or all of these components may also be used in surface pumping operations.

As used in this disclosure, the terms “upstream” and “downstream” will be understood to refer to relative positions within pumping system 100 as defined by the movement of fluid through pumping system 100 from wellbore 104 to wellhead 106 . The term "longitudinal" will be understood to mean along a central axis extending through pumping system 100; the term "radial" will be understood to mean along a direction perpendicular to the longitudinal axis; Rotational position or movement of the longitudinal axis.

The motor 110 is a submersible electric motor that receives power via a power cable 114 from a surface based facility. When electrical power is supplied to the motor 110 , the motor converts the electrical power into rotational motion, which is transmitted along a shaft (not shown in FIG. 1 ) to the pump 108 . In some embodiments, the motor 110 is a three-phase motor controlled by a variable speed drive 116 located at the surface. Variable speed drive 116 selectively controls the speed, torque, and other operating characteristics of motor 110 .

Seal section 112 is positioned above motor 110 and below pump 108 . Seal section 112 shields motor 110 from mechanical thrust generated by pump 108 and isolates motor 110 from drilling fluid in pump 108 . Seal section 112 may also be used to accommodate expansion and contraction of lubricant within motor 110 during installation and operation of pumping system 100 . In some embodiments, sealing section 112 is incorporated within motor 110 or within pump 108 .

Unlike prior art electrically powered submersible pumping systems, pump 108 is a rotary hydraulic pump driven by motor 110 . Pump 108 converts the rotational motion produced by motor 110 into linear motion that drives a reciprocating piston within pump 108 . Although a single pump 108 is depicted in FIG. 1 , it will be appreciated that the pump 108 may be used in combination with additional pumps and motors. For example, pump 108 may be used with other hydraulic rotary pumps to feed surface-based sucker rod pumps or to feed centrifugal pumps.

In the embodiment depicted in FIG. 2 , the pump 108 uses an inclined plate to convert the rotational movement of the motor 110 into reciprocating linear motion. In the cross-sectional view of pump 108 in FIG. 2 , pump 108 includes an upstream chamber 118 , a downstream chamber 120 and a pump shaft 122 . However, it will be appreciated that the scope of the exemplary embodiments is not limited to dual chamber designs. Pump 108 may alternatively include a single chamber or more than two chambers.

The pump 108 also includes a suction port 124 , a discharge port 126 and a housing 128 . Each of the internal components within pump 108 are housed within housing 128 . Fluid from well 104 enters pump 108 through suction 124 and is carried by upstream chamber 118 and downstream chamber 120 through discharge 126 to production tubing 102 . A pump shaft 122 is coupled from the motor 110 to an output shaft (not shown), either directly or through a series of interconnected shafts. The pump 108 may include one or more shaft seals that seal the shaft 122 as it passes through the upstream chamber 118 and the downstream chamber 120 .

Each of upstream chamber 118 and downstream chamber 120 includes a cylinder block 130 , one or more piston assemblies 132 and a swash plate assembly 134 . Swash plate assembly 134 includes a drive plate 136 and a rocker plate 138 . 5 and 6 show the upstream face of rocker plate 138 and the upstream face of drive plate 136 . Both the rocker plate 138 and the drive plate 136 may be formed as generally cylindrical members.

Referring back to FIG. 2 , the drive plate 136 is coupled to the pump shaft 122 in a non-perpendicular orientation. In this manner, rotation of pump shaft 122 causes the upstream and downstream edges of drive plate 136 to rotate about shaft 122 within upstream chamber 118 and downstream chamber 120 at opposite times. In some embodiments, drive plate 136 is coupled to pump shaft 122 at a fixed angle. In other embodiments, the angular setting of the connection between drive plate 136 and pump shaft 122 may be adjusted during use.

The rocker plate 138 is not configured for rotation with the pump shaft 22 and remains rotationally fixed relative to the cylinder block 130 and housing 128 . In some embodiments, the upstream face of the rocker plate 138 is in sliding contact with the downstream face of the drive plate 136 . In other embodiments, pump 108 includes bearings between rocker plate 138 and drive plate 136 to reduce friction between the two components.

The rocker plate 138 includes a center bearing 140 and a piston rod notch 142 . Center bearing 140 allows rocker plate 138 to tilt in response to rotation of adjacent drive plate 136 . Thus, as drive plate 136 rotates with pump shaft 122 , the varying rotational position of the downstream edge of drive plate 136 causes rocker plate 138 to tilt in a rolling fashion while maintaining radial alignment with cylinder block 130 and housing 128 . Center bearing 140 may include a ball bearing, lip seal, or other bearing that allows rocker plate 138 to tilt in a longitudinal manner while remaining rotationally stationary.

Referring now to FIGS. 2 , 3 and 4 , cylinder block 130 is secured within housing 128 . The cylinder block 130 includes a plurality of cylinders 144 , a suction port 146 and a one-way valve 148 . In the exemplary embodiment depicted in FIGS. 3 and 4 , cylinder block 130 includes six cylinders 144 , six suction ports 146 , six suction valves 148 , and six discharge valves 150 . However, it will be appreciated that the cylinder block 130 may include a different number of cylinders 144 , suction ports 146 and one-way valves 148 .

The piston assembly 132 includes a piston rod 152 and a plunger 154 . In the embodiment depicted in FIG. 3 , the pump 108 includes six piston assemblies 132 . However, it will be appreciated that fewer or greater numbers of piston assemblies 132 may also be used. The proximal end of each piston rod 152 is secured within a corresponding one of the piston rod notches 142 in the rocker plate 138 . The distal end of each of the piston rods 152 is attached to a plunger 154 . Each plunger 154 resides within a corresponding one of the cylinders 144 .

In the embodiment depicted in FIG. 3 , the suction port 146 extends to the upstream side of the cylinder block 130 . A suction valve 148 in the suction port 146 allows fluid to enter the suction port 146 from the upstream side of the cylinder block 130 but prevents fluid from passing back from the upstream side of the cylinder block 130 . A corresponding drain valve 150 allows fluid to exit the cylinder 144 but prevents fluid from entering the cylinder 144 .

In an alternative embodiment depicted in FIG. 7 , the suction port 146 extends through the downstream side of the single cylinder block 130 . A suction valve 148 within the suction port 146 allows fluid to enter the suction port 146 from the downstream side of the cylinder block 130 but prevents fluid from passing back from the suction port 146 . A corresponding drain valve 150 allows fluid to exit the cylinder 144 but prevents fluid from entering the cylinder 144 . In the embodiment depicted in FIG. 7 , it may be desirable to attach exhaust pipe 156 to each of cylinders 144 to prevent recirculation of fluid through cylinder block 130 .

During operation, motor 110 turns pump shaft 122 , which in turn rotates drive plate 136 . As drive plate 136 rotates, it imparts reciprocating longitudinal motion to rocker plate 136 . For each full rotation of drive plate 136 , rocker plate 138 undergoes a complete cycle of reciprocating linear motion. The linear reciprocating motion of the rocker plate 138 is transmitted to the plunger 154 through the piston rod 152 . Piston rod 152 forces plunger 154 to move back and forth within cylinder 144 .

As plunger 154 moves in an upstream direction, fluid is drawn into the cylinder through suction port 146 and suction valve 148 . As plunger 154 continues to reciprocate and move in the downstream direction, suction valve 148 closes and fluid is forced out of cylinder 144 through discharge valve 150 . In this manner, the stroke of piston assembly 132 is controlled by the longitudinal distance between the upstream and downstream edges of rocker plate 138 . The rate at which piston assembly 132 reciprocates within cylinder block 130 is controlled by the rotational speeds of motor 110 and pump shaft 122 .

Turning to FIG. 8 , therein is shown a cross-sectional view of a pump 108 constructed in accordance with another embodiment. In the embodiment depicted in FIG. 8 , the pump 108 uses a central camshaft 158 to drive one or more series of pistons 160 within a bank of cylinders 162 . The cylinder 162 is connected to a manifold 164 that extends the length of the pump 108 . In an exemplary embodiment, the pump 108 includes 2, 4, 6 or 8 banks of cylinders 162, a manifold 164 and a series of pistons 160, as depicted in the top cross-sectional view of FIG. 108 are equally distributed.

The camshaft 158 includes a plurality of radially offset protrusions 166, and the connecting rod 168 is fixed to the plurality of radially offset protrusions 166 for rotation. Camshaft 158 is coupled directly or indirectly to an output shaft from motor 110 such that operation of motor 110 causes camshaft 158 to rotate at a desired speed. It will be appreciated that the piston 160 , camshaft 158 and connecting rod 168 may include additional features known in the art not shown or described including, for example, toggle pins, piston seal rings, and piston skirts. Each set of pistons 160 and connecting rods 168 may be referred to collectively as a "piston assembly" within the description of this embodiment.

Each of manifolds 164 includes an inlet 170 and an outlet 172 and one or more check valves 174 . Inlet 170 is connected to pump suction 124 and outlet 172 is connected to discharge 126 . In the embodiment depicted in FIG. 8 , each manifold 164 includes a separate check valve between adjacent pistons 160 . Check valve 174 prevents fluid from moving upstream in the direction from outlet 172 to inlet 170 . In this manner, check valve 174 divides manifold 164 into individual stages 176 that are associated with each of piston 160 and cylinder 162 .

During operation, camshaft 158 rotates and causes piston 160 to move in a reciprocating linear motion according to well known mechanics. As the piston 160 is retracted from the manifold 164 , a temporary pressure reduction occurs within the portion of the manifold 164 adjacent to the cylinder 162 from which the piston 160 is retracted. The pressure reduction creates suction that draws fluid from the adjacent upstream stage 176 into the stage 176 through the interposed check valve 174 .

During the compression stroke, piston 160 moves through cylinder 162 toward manifold 164 , thereby reducing the volume of cylinder 162 and the open portion of stage 176 . As pressure increases in stage 176 adjacent piston 160 in the compression stroke, fluid is vented through check valve 174 to the adjacent downstream stage. The configuration and timing of the camshaft 158 can be optimized to produce a suction-compression cycle within each stage 176 that is partially or fully offset between adjacent stages 176, which provides a sequential step of fluid passage through the manifold 164. into the mobile.

In an alternative embodiment, piston 160 is configured to extend into manifold 164 . In another embodiment, check valve 174 is omitted, and advancement of fluid through manifold 164 passes to maintain piston 160 in a closed position within manifold 164 to act as a stop against reverse movement of fluid toward inlet 170 made possible. As an alternative to camshaft 158 and connecting rod 168, the timing of piston 160 may be controlled using a lobed cam and rocker arm. In this manner, piston 160 creates a rolling progressive chamber within manifold 164 that pushes fluid downstream through pump 108 .

Thus, in each of the embodiments disclosed herein, the pump 108 provides a positive displacement linear reciprocating pump powered by the rotating shaft of a conventional submersible motor 110 . The pump 108 will find particular utility in smaller volume pump operations and in the well 104 giving fluids with large gas fractions. The pump 108 is also well suited for deployment in deviated (non-vertical) wells 104 because the pump 108 can be configured to be shorter than conventional multistage centrifugal pumps.

It will be appreciated that while numerous features and advantages of various embodiments of the invention are set forth in the foregoing description, along with details of structure and function of various embodiments of the invention, this disclosure is illustrative only and does not vary To the full extent indicated by the broad ordinary meaning of the terms expressed in the appended claims, especially in matters of construction and arrangement of parts within the principles of the invention. Those skilled in the art will recognize that the teachings of the present invention may be applied to other systems without departing from the scope and spirit of the present invention.

Claims (20)

1. A submersible pumping system comprising: electric motors; and A pump driven by the electric motor, wherein the pump comprises: a shaft driven by said motor configured for rotational movement; one or more piston assemblies configured for linear reciprocating movement; and Wherein the reciprocating piston is configured to linearly reciprocate in response to the rotational movement of the shaft. 2. The submersible pumping system of claim 1, wherein the pump further comprises a swash plate coupled to the reciprocating piston and the shaft, wherein the swash plate assembly The rotational movement is converted into the linear reciprocating motion of the reciprocating piston. 3. The submersible pumping system of claim 2, wherein the swash plate assembly further comprises: driver board; and Rocker plate. 4. The submersible pumping system of claim 3, wherein the drive plate is connected to the rotating shaft at a non-perpendicular angle. 5. The submersible pumping system of claim 4, wherein the rocker plate is adjacent to the drive plate. 6. The submersible pumping system of claim 5, wherein the rocker plate does not rotate with the shaft. 7. The submersible pumping system according to claim 6, wherein the rocker plate further comprises: center bearing; and One or more piston rod notches. 8. The submersible pumping system of claim 2, wherein the pump further comprises a cylinder block, and wherein the cylinder block comprises: one or more suction ports; a suction valve in each of the one or more suction ports; and A discharge valve in each of the one or more cylinders. 9. The submersible pumping system of claim 1, wherein said pump further comprises a camshaft assembly, wherein said camshaft assembly converts said rotational movement of said shaft into said reciprocating piston The linear reciprocating motion. 10. The submersible pumping system of claim 9, wherein the camshaft assembly comprises: camshaft; a plurality of lobes on the camshaft; and A plurality of connecting rods connected between the boss on the camshaft and the piston assembly. 11. The submersible pumping system of claim 10, wherein the pump includes a plurality of cylinders, wherein each of the piston assemblies reciprocates within a separate one of the plurality of cylinders. 12. The submersible pumping system of claim 11, wherein the pump further comprises a plurality of manifolds, wherein each of the plurality of cylinders intersects a manifold. 13. The submersible pumping system of claim 12, wherein the pump further comprises a plurality of check valves in each of the plurality of manifolds. 14. The submersible pumping system of claim 12, wherein said lobe on said camshaft has a stepped profile that causes said piston assembly to create said plurality of manifolds. Each of the inner progressive chambers reciprocates sequentially. 15. The submersible pumping system of claim 1, further comprising a sealing section positioned between the pump and the motor. 16. A pump usable within a submersible pumping system, the pump comprising: a cylinder block, wherein the cylinder block includes a plurality of cylinders; rotatable shaft; A swash plate assembly, wherein the swash plate assembly includes: a drive plate connected to the rotatable shaft and configured to rotate with the shaft; and a rocker plate not configured to rotate with the shaft; and A plurality of piston assemblies, wherein each of the plurality of piston assemblies includes: a plunger configured for reciprocating linear motion in a corresponding one of the plurality of cylinders; and A piston rod connected to the plunger and the rocker plate. 17. The pump of claim 16, wherein said cylinder block further comprises: Multiple suction ports; a suction valve in each of the plurality of suction ports; and A discharge valve in each of the plurality of cylinders. 18. A pump usable within a submersible pumping system, the pump comprising: multiple manifolds; a plurality of cylinder banks, wherein each of the plurality of cylinder banks corresponds to a separate one of the plurality of manifolds; a plurality of cylinders within each of the plurality of cylinder banks, wherein each of the plurality of cylinders is in fluid communication with a corresponding one of the plurality of manifolds; a rotatable camshaft; and A plurality of piston assemblies, wherein each of the piston assemblies includes: pistons, wherein each piston is located in a separate one of the plurality of cylinders; and a connecting rod, wherein the connecting rod connects the piston to the camshaft. 19. The pump of claim 18, further comprising a plurality of check valves in each of the plurality of manifolds. 20. The pump of claim 18, wherein said camshaft has a stepped profile that causes said piston assembly to reciprocate sequentially in a manner that creates progressive chambers within each of said plurality of manifolds .