CN-122014579-A - Hydraulic drive downhole motor pump assembly and gas production system

CN122014579ACN 122014579 ACN122014579 ACN 122014579ACN-122014579-A

Abstract

The invention aims to provide a hydraulic drive downhole motor pump assembly and a gas production system, wherein the proximal end of a plunger assembly is positioned in a pipe cavity of an inner pipe of an upper double-layer pipe column and is in sliding sealing connection with the inner pipe of the upper double-layer pipe column, the distal end of the plunger assembly penetrates through a joint assembly and is positioned in the inner pipe of a lower double-layer pipe column and is positioned at the proximal end of a fixed valve, the joint assembly is in sliding sealing connection with the plunger assembly, the proximal end of the joint assembly and the inner pipe of the upper double-layer pipe column are enclosed to form a compression cavity, the inner pipe of the upper double-layer pipe column is provided with a diversion hole communicated with a gap between the compression cavity and the inner pipe and the outer pipe of the upper double-layer pipe column, the inner pipe of the upper double-layer pipe column is communicated with the inner cavity of the plunger assembly, and a one-way valve assembly is positioned in the cavity and/or at the end of the plunger assembly. The invention can solve the problems of drainage and gas production of deep and large-displacement wells, and simultaneously solves the problems of low exploitation efficiency, high cost, low reliability and low service life of the conventional jet pump.

Inventors

GUO DENGMING
XIA ZHENHUA

Assignees

湖北明艳机械制造有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260319

Claims (10)

1. The hydraulic drive downhole motor pump assembly is characterized by comprising an upper double-layer pipe column, a plunger assembly, a joint assembly, a one-way valve assembly, a lower double-layer pipe column and a fixed valve; The distal end of the upper double-layer pipe column is connected with the proximal end of the joint assembly respectively, the proximal end of the lower double-layer pipe column is connected with the joint assembly, and the fixed valve is connected with the distal end of the inner pipe of the lower double-layer pipe column; the proximal end of the plunger assembly is positioned in the lumen of the inner pipe of the upper double-layer pipe column and is in sliding sealing connection with the inner pipe of the upper double-layer pipe column, the distal end of the plunger assembly penetrates through the joint assembly and is positioned in the inner pipe of the lower double-layer pipe column and is in sliding sealing connection with the joint assembly and the plunger assembly; the plunger assembly, the proximal end of the joint assembly and the inner pipe of the upper double-layer pipe column are enclosed to form a compression cavity, and the inner pipe of the upper double-layer pipe column is provided with a diversion hole communicated with the compression cavity and a gap between the inner pipe and the outer pipe of the upper double-layer pipe column; The inner pipe of the upper double-layer pipe column is communicated with the inner cavity of the plunger assembly, the one-way valve assembly is arranged on the plunger assembly, and the one-way valve assembly is positioned in the pipe cavity and/or the end head of the plunger assembly.
2. The fluid driven downhole motor pump assembly of claim 1, wherein the plunger assembly is slidably connected to the inner tube of the lower double-layer tubing string, an auxiliary chamber is formed between the joint assembly, the plunger assembly and the inner tube of the lower double-layer tubing string, a communication hole is formed in a chamber wall of the auxiliary chamber, one end of the communication hole is communicated with the auxiliary chamber, the other end of the communication hole is communicated with the inner chamber of the plunger assembly, and/or is communicated with a gap between the inner tube of the lower double-layer tubing string and the outer tube of the lower double-layer tubing string.
3. The hydraulically driven downhole motor pump assembly of claim 2, wherein the plunger assembly comprises a motor plunger, a hollow pull rod plunger and a pump plunger connected in sequence from top to bottom, the motor plunger is in sliding sealing connection with the inner tube of the upper double-layer tubing string, the proximal end of the hollow pull rod plunger is positioned in the lumen of the inner tube of the upper double-layer tubing string, the distal end of the hollow pull rod plunger passes through the joint assembly and is positioned in the inner tube of the lower double-layer tubing string, the hollow pull rod plunger portion is in sliding sealing connection with the joint assembly, the pump plunger is positioned in the inner tube of the lower double-layer tubing string, the pump plunger is in sliding sealing connection with the inner tube of the lower double-layer tubing string, the auxiliary cavity is formed by the joint assembly, the pump plunger, the hollow pull rod plunger and the inner tube of the lower double-layer tubing string, and the other end of the communication hole is communicated with the inner cavity of the hollow pull rod plunger.
4. A hydraulically driven downhole motor pump assembly as recited in claim 3, wherein the one-way valve assembly comprises a drain valve located between the motor plunger and the hollow pull rod plunger and a traveling valve block located on the pump plunger.
5. The hydraulically driven downhole motor pump assembly as recited in claim 4, wherein the traveling block comprises an upper traveling valve and a lower traveling valve, the upper traveling valve being located between the proximal end of the pump plunger and the hollow pull rod plunger, the lower traveling valve being located at the distal end of the pump plunger.
6. A hydraulically driven downhole motor pump assembly as recited in claim 4 or 5, wherein a lower bumper is provided at a distal end of the motor plunger and a lower bumper cavity is provided at a proximal end of the adapter assembly that mates with the lower bumper.
7. A hydraulically driven downhole motor pump assembly as recited in claim 4 or 5, further comprising a nipple, an nipple assembly and an outer nipple, the nipple assembly disposed within the lumen of the outer nipple with an annular lumen formed therebetween, a proximal end of the nipple connecting the nipple assembly and the outer nipple, a distal end of the nipple connecting the inner and outer tubes of the upper double-layer tubing string and communicating a gap between the inner and outer tubes of the upper double-layer tubing string with the inner tube of the nipple assembly and communicating a gap between the nipple assembly and the outer nipple with the lumen of the inner tube of the upper double-layer tubing string.
8. The hydrodynamically driven downhole motor pump assembly of claim 7, wherein the nipple assembly comprises a setting nipple and a setting nipple, the setting nipple being connected to the setting nipple and the setting nipple being connected to the shunt nipple.
9. The fluid driven downhole motor pump assembly as recited in claim 7, wherein said diverter sub is provided with an upper buffer chamber at a distal end thereof and said motor plunger is provided with an upper buffer at a proximal end thereof that mates with said upper buffer chamber.
10. A gas production system comprising a surface power system and a hydraulically driven downhole motor pump assembly as claimed in any one of claims 1 to 9, the surface power system providing power fluid to the hydraulically driven downhole motor pump assembly.

Description

Hydraulic drive downhole motor pump assembly and gas production system Technical Field The invention relates to the technical field of underground motor pumps for deep coal bed gas exploitation, in particular to a hydraulic drive underground motor pump assembly and a gas production system. Background In deep coal bed gas (commonly known as gas) exploitation, a hydraulic drive downhole motor pump is a key downhole drainage device. The working principle is that high-pressure power liquid generated by a ground pump station is conveyed into the well through a pipeline to drive a hydraulic drive underground motor pump to work so as to extract water in a coal bed, thereby realizing drainage and gas production. The hydraulic drive downhole motor pump assembly in the prior art has the core defect that the power hydraulic pressure required for driving the hydraulic pump to work is too high. Along with the continuous increase of the coal bed gas exploitation depth, especially in deep exploitation scenes, in order to overcome huge hydrostatic pressure and pipeline on-way resistance brought by deep wells, the power hydraulic pressure supplied by the ground must be greatly lifted so as to ensure that the underground motor pump can work normally and achieve the required drainage and exploitation lift. However, this need for high pressure presents a series of problems: Surface equipment capabilities are limited-conventional surface power equipment (e.g., high pressure plunger pumps) have technical limitations in terms of output pressure. When the depth of production reaches a certain level, the required power hydraulic pressure exceeds the rated working pressure range of conventional equipment, resulting in expensive surface equipment or failure to meet the process requirements of deep production. The difficulty and cost of equipment manufacture increases dramatically, and in order to meet higher working pressure, high-power ground power equipment capable of bearing ultra-high pressure and a high-pressure manifold system matched with the equipment must be developed and manufactured. The method not only puts very high requirements on the strength and the tightness of materials and the processing technology of equipment, but also increases the manufacturing difficulty by times, and simultaneously greatly increases the equipment investment and the operation and maintenance cost. The reliability and the service life of the system are reduced, namely, the whole hydraulic driving system operates under the ultra-high pressure working condition, all parts (including a ground pump, a high-pressure pipeline, a downhole motor sealing element and the like) bear extremely high alternating stress, and fatigue damage, sealing failure and abnormal wear are easy to occur, so that the operation reliability and the service life of the whole system are obviously reduced, the equipment replacement and maintenance frequency is increased, and the continuity and the economy of coal bed gas exploitation are influenced. Disclosure of Invention The invention aims to provide a hydraulic drive underground motor pump assembly and a gas production system, which are used for solving the problems of low exploitation efficiency, high cost, low reliability and low service life of deep coal bed gas caused by overlarge pressure of power fluid required by the existing hydraulic drive underground motor pump assembly when the hydraulic drive underground motor pump assembly works. The invention provides a hydraulic drive downhole motor pump assembly, which comprises an upper double-layer pipe column, a plunger assembly, a joint assembly, a one-way valve assembly, a lower double-layer pipe column and a fixed valve, wherein the distal end of the upper double-layer pipe column is connected with the proximal end of the joint assembly respectively, the proximal end of the lower double-layer pipe column is connected with the joint assembly, the fixed valve is connected with the distal end of an inner pipe of the lower double-layer pipe column, the proximal end of the plunger assembly is positioned in a pipe cavity of the inner pipe of the upper double-layer pipe column and is in sliding sealing connection with the inner pipe of the upper double-layer pipe column, the distal end of the plunger assembly penetrates through the joint assembly and is positioned in the inner pipe of the lower double-layer pipe column and is positioned at the proximal end of the fixed valve, the joint assembly is in sliding sealing connection with the plunger assembly, the proximal end of the plunger assembly, the inner pipe of the joint assembly and the inner pipe of the upper double-layer pipe column enclose a compression cavity, the inner pipe of the upper double-layer pipe is provided with a diversion hole communicating a gap between the compression cavity and the inner pipe of the upper double-layer pipe column and the inner pipe, the one-way valve assembly is arranged in the pipe assem