CN117108599A - Hydraulic power device for underground hydraulic cylinder of coal bed gas and hydraulic cylinder control method - Google Patents

Abstract

The application discloses a hydraulic power device for a hydraulic cylinder under a coal bed gas well and a control method thereof, wherein the hydraulic power device comprises: the device comprises an oil storage unit, a driving unit, a reversing unit and a pressure detection unit, wherein the driving unit receives a starting signal output by an on-well electronic control device and then converts hydraulic oil into pressure oil to be output; the reversing unit is communicated with the driving unit and is provided with a first oil outlet and a second oil outlet, and the pressure detection unit is arranged on the reversing unit and is electrically connected with the on-well electronic control equipment and is used for outputting a pressure signal after detecting the pressure value of the pressure oil; the on-well electric control equipment outputs a switching control signal to the reversing unit according to the pressure signal, and the reversing unit selects to correspondingly output the pressure oil output by the driving unit to the first piston chamber or the second piston chamber through the first oil outlet or the second oil outlet according to the switching control signal so as to drive the hydraulic cylinder to perform reversing operation.

Description

Hydraulic power device for underground hydraulic cylinder of coal bed gas and hydraulic cylinder control method

Technical Field

The application belongs to the technical field of coalbed methane exploitation, and particularly relates to a hydraulic power device for a hydraulic cylinder under a coalbed methane well and a hydraulic cylinder control method.

Background

Referring to fig. 1, fig. 1 is a schematic diagram of a coal bed methane downhole drainage device in the prior art. As shown in FIG. 1, the device comprises a hydraulic pump station 11 and a multi-core pipeline 12, wherein the multi-core pipeline 12 comprises two hydraulic oil pipes 121 and a drain pipe 122, and the drainage device adopts hydraulic oil to drive an underground hydraulic oil cylinder to do bidirectional reciprocating motion so as to drain underground water out of the ground through the drain pipe 122, thereby achieving the purpose of gas production. Hydraulic oil is provided by an aboveground hydraulic pump station 11 and is connected with an underground hydraulic oil cylinder through two hydraulic oil pipes 121, and the hydraulic oil enters the ground in two paths to drive the hydraulic oil cylinder to move. Thus, when the drainage and production equipment works, the underground hydraulic cylinder needs three pipes (two hydraulic oil pipes 121 and one drain pipe 122) to be connected with the underground hydraulic cylinder, and the underground hydraulic cylinder is connected with an underground hydraulic pump station to drain water. In actual use, three pipes are arranged in a thick rubber pipe to form a multi-core pipeline, and refer to fig. 2.

However, in practice, it is found that, because the weight of the multicore pipeline is very large, in order to prevent the risk of the pipeline falling rapidly due to the excessive gravity of the pipeline when the multicore pipeline is conveyed underground, the requirements on the ground facilities and the conveying equipment are very high, so that the facilities and the equipment on the ground are relatively huge, the manufacturing cost is correspondingly high, meanwhile, the existing hydraulic power device mostly adopts a motor as a reversing unit, namely, the hydraulic cylinder is driven to reverse by the forward and reverse rotation of the motor, so that the motor is excessively worn, and the production cost is correspondingly increased.

Accordingly, there is a need to develop a hydraulic power unit for a hydraulic cylinder in a coal bed methane well and a hydraulic cylinder control method that overcome the above-mentioned drawbacks.

Disclosure of Invention

In view of the above problems, the present application provides a hydraulic power device for a hydraulic cylinder under a coal bed gas well, comprising:

an oil storage unit which accommodates hydraulic oil;

the driving unit is electrically connected with the aboveground electric control equipment and converts the hydraulic oil into pressure oil to be output after receiving a starting signal output by the aboveground electric control equipment;

the reversing unit is communicated with the driving unit and is provided with a first oil outlet and a second oil outlet, and the reversing unit is correspondingly communicated with a first piston chamber and a second piston chamber of a hydraulic cylinder through the first oil outlet and the second oil outlet respectively;

the pressure detection unit is arranged on the reversing unit and is electrically connected with the well electric control equipment, and the pressure detection unit is used for outputting a pressure signal after detecting the pressure value of the pressure oil;

the above-well electric control equipment outputs a switching control signal to the reversing unit according to the pressure signal, and the reversing unit selects to correspondingly output the pressure oil output by the driving unit to the first piston chamber or the second piston chamber through the first oil outlet or the second oil outlet according to the switching control signal so as to drive the hydraulic cylinder to perform reversing operation.

The hydraulic power device described above, wherein the driving unit includes:

the integrated block is provided with a first end face and a second end face which are oppositely arranged, and the oil storage unit is arranged on the first end face;

the hydraulic pump is arranged on the second end face of the integrated block and is communicated with the reversing unit;

the motor is arranged on the first end face and connected with the hydraulic pump, the motor drives the hydraulic pump to work according to the starting signal, and the hydraulic pump converts hydraulic oil in the oil storage unit into pressure oil and outputs the pressure oil to the reversing unit.

The hydraulic power device comprises a first end face, a first through hole, an X1 oil hole and a T1 oil hole, wherein the first through hole extends from the first end face to the second end face, the driving unit further comprises a connecting piece, the connecting piece is arranged in the first through hole, the motor is connected with the hydraulic pump through the connecting piece, and the oil storage unit is communicated with the X1 oil hole and the T1 oil hole;

the second end face is provided with a P1 oil hole, a T2 oil hole, a P2 oil hole and an X2 oil hole, the P1 oil hole and the T2 oil hole are communicated with the reversing unit, and the P2 oil hole and the X2 oil hole are communicated with the hydraulic pump;

after the hydraulic pump sucks hydraulic oil through the X2 oil hole and the X1 oil hole, the hydraulic pump outputs pressure oil to the reversing unit through the P2 oil hole and the P1 oil hole, and return oil of the reversing unit flows back to the oil storage unit through the T2 oil hole and the T1 oil hole.

The above-mentioned hydraulic power unit, wherein, the switching-over unit includes:

the valve seat is provided with two opposite side end surfaces, a P3 oil hole and a T3 oil hole are formed in one side end surface of the valve seat, an A1 oil hole, a B1 oil hole and a C oil hole are formed in the other side end surface of the valve seat, the T3 oil hole is communicated with the T2 oil hole, the P3 oil hole is communicated with the P1 oil hole, the pressure detection unit is arranged on the C oil hole, and the A1 oil hole and the B1 oil hole are correspondingly communicated with the first piston chamber and the second piston chamber;

the reversing valve is arranged on the top surface of the valve seat and is communicated with the valve seat, and the reversing valve is electrically connected with the uphole electric control equipment;

after the pressure oil flows into the reversing valve through the P3 oil hole, the reversing valve outputs the pressure oil to the A1 oil hole or the B1 oil hole according to the switching control signal, wherein the A1 oil hole and the B1 oil hole are the first oil outlet hole and the second oil outlet hole respectively.

The hydraulic power device comprises a valve seat, wherein a T4 oil hole, a P4 oil hole, an A2 oil hole and a B2 oil hole are formed in the top surface of the valve seat, a T5 oil hole, a P5 oil hole, an A3 oil hole and a B3 oil hole are formed in the bottom surface of the reversing valve, and the T4 oil hole, the P4 oil hole, the A2 oil hole and the B2 oil hole are in one-to-one corresponding alignment communication with the T5 oil hole, the P5 oil hole, the A3 oil hole and the B3 oil hole;

the pressure oil flows into the reversing valve through the P3 oil hole, the P4 oil hole and the P5 oil hole and then is output to the A1 oil hole through the A3 oil hole and the A2 oil hole, or is output to the B1 oil hole through the B3 oil hole and the B2 oil hole;

the return oil in the reversing valve flows back to the T2 oil hole through the T5 oil hole, the T4 oil hole and the T3 oil hole.

The hydraulic power device comprises a pressure detection unit, a P3 oil hole and a P4 oil hole, wherein the pressure detection unit is communicated with a connecting passage of the P3 oil hole and the P4 oil hole so as to collect the pressure value of hydraulic oil.

The above-mentioned hydraulic power unit, wherein, the switching-over unit still includes the overflow valve, set up on the disk seat P3 oilhole and still set up Y oilhole on the terminal surface of T3 oilhole, the overflow valve install in on the Y oilhole and electric connection in aboveground electrical control equipment, aboveground electrical control equipment is according to pressure signal monitoring hydraulic power unit's system pressure, when the pressure value exceeds a threshold value, aboveground electrical control equipment output pressure limiting signal extremely the overflow valve, the overflow valve is according to pressure limiting signal work.

The hydraulic power device is characterized in that the overflow valve is communicated with a connecting passage of the P3 oil hole and the P4 oil hole.

The hydraulic power device further comprises a housing, wherein the housing is provided with an accommodating space and two open ends communicated with the accommodating space, and the oil storage unit, the reversing unit and the pressure detection unit are arranged in the accommodating space.

The application also provides a hydraulic cylinder control method, which is applied to the hydraulic power device described in any one of the above, and comprises the following steps:

the hydraulic oil of the oil storage unit is converted into pressure oil by the driving unit according to a starting signal output by the on-well electronic control equipment and is output to the reversing unit;

the reversing unit correspondingly outputs the pressure oil to a first piston chamber or a second piston chamber of the hydraulic cylinder through a first oil outlet or a second oil outlet so as to drive the hydraulic cylinder to work;

the pressure value of the pressure oil is acquired in real time through a pressure detection unit, and then a pressure signal is output to the on-well electronic control equipment;

and outputting the switching control signal to the reversing unit through the aboveground electric control equipment according to the pressure signal, wherein the reversing unit selects to correspondingly output the pressure oil output by the driving unit to the second piston chamber or the first piston chamber through the second oil outlet or the first oil outlet according to the switching control signal so as to drive the hydraulic cylinder to perform reversing operation.

Compared with the prior art, the application has the following effects: according to the application, the driving unit, the oil storage unit and the reversing unit are arranged underground, and the underground hydraulic cylinder is directly driven to work after pressure oil is generated, so that the original technical problem is thoroughly solved; meanwhile, a hydraulic pump station is not required to be arranged on the well, two hydraulic oil pipes in the multi-core pipeline are omitted, correspondingly, two circuits are replaced, one circuit is used for the positive electrode and the negative electrode of the motor, and the other circuit is used for a signal circuit of the pressure sensor, so that the overall dimension of the multi-core pipeline is greatly reduced, the weight of the pipeline is reduced by more than 80%, and the load is well reduced for the well facilities and conveying equipment; meanwhile, the reversing valve drives the hydraulic cylinder to reverse, so that the abrasion of the motor is reduced, and the production cost is reduced.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a prior art coal bed methane downhole drainage and production apparatus;

FIG. 2 is a schematic diagram of a prior art multi-core pipe;

FIG. 3 is a schematic view of the hydraulic power unit of the present application;

FIG. 4 is an exploded view of a hydraulic power unit;

FIG. 5 is a schematic view of a structure of a first end face of an integrated block;

FIG. 6 is a schematic diagram of a structure of a second end face of the manifold block;

FIG. 7 is an oil circuit diagram of the interior of the valve seat;

FIG. 8 is a flow chart of a control method of the present application;

FIG. 9 is a position diagram of a hydraulic power unit of the present application;

fig. 10 is a schematic view of an oil hole of the reversing valve.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The exemplary embodiments of the present application and the descriptions thereof are intended to illustrate the present application, but not to limit the present application. In addition, the same or similar reference numerals are used for the same or similar parts in the drawings and the embodiments.

The terms "first," "second," "S1," "S2," …, and the like, as used herein, do not denote a particular order or sequence, nor are they intended to limit the application, but rather are merely intended to distinguish one element or operation from another in the same technical terms.

With respect to directional terms used herein, for example: upper, lower, left, right, front or rear, etc., are merely references to the directions of the drawings. Thus, directional terminology is used for purposes of illustration and is not intended to be limiting.

As used herein, the terms "comprising," "including," "having," "containing," and the like are intended to be inclusive and mean an inclusion, but not limited to.

As used herein, "and/or" includes any or all combinations of such things.

Reference herein to "a plurality" includes "two" and "more than two"; the term "plurality of sets" as used herein includes "two sets" and "more than two sets".

Certain words used to describe the application will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the application.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a hydraulic power device according to the present application. As shown in fig. 3, a hydraulic power device of the present application is used for controlling a hydraulic cylinder under a coalbed methane well, and the hydraulic power device includes: the hydraulic oil storage device comprises an oil storage unit 21, a driving unit 22, a reversing unit 23 and a pressure detection unit 24, wherein hydraulic oil is contained in the oil storage unit 21; the driving unit 22 is electrically connected to an electrical control device (not shown) on the well, and receives a start signal output by the electrical control device on the well, converts the hydraulic oil into pressure oil, and outputs the pressure oil; the reversing unit 23 is communicated with the driving unit 22, and the reversing unit 23 is provided with a first oil outlet and a second oil outlet and is correspondingly communicated with a first piston chamber and a second piston chamber of a hydraulic cylinder respectively through the first oil outlet and the second oil outlet; the pressure detection unit 24 is arranged on the reversing unit 23 and is electrically connected to the well electric control equipment, and the pressure detection unit 24 is used for detecting the pressure value of the pressure oil and then outputting a pressure signal; the above-well electronic control device outputs a switching control signal to the reversing unit 23 according to the pressure signal, and the reversing unit 23 selects to correspondingly output the pressure oil output by the driving unit 22 to the first piston chamber or the second piston chamber through the first oil outlet or the second oil outlet according to the switching control signal so as to drive the hydraulic cylinder to perform reversing operation.

In this embodiment, the oil storage unit is a preferred oil storage bag, which is a storage device for hydraulic oil, and is fixed on the driving unit 22 through a bolt connection, and two oil holes are formed at the bottom of the oil storage bag and are respectively communicated with the driving unit 22, wherein one of the two oil holes is used for supplying the hydraulic oil in the oil storage bag to the two oil holes, and the other oil hole is used for recovering the return oil of the reversing unit 23.

Further, referring to fig. 4, fig. 4 is an exploded view of the hydraulic power unit. As shown in fig. 4, the driving unit 22 includes: the integrated block 221, the hydraulic pump 222 and the motor 223, the integrated block 221 has a first end surface S1 and a second end surface S2 which are oppositely arranged, and the oil storage unit 21 is installed on the first end surface S1; the hydraulic pump 222 is installed on the second end surface S2 of the integrated block 221 and is communicated with the reversing unit 23; the motor 223 is installed on the first end surface S1 and is connected to the hydraulic pump 222, the motor 223 drives the hydraulic pump 222 to work according to the start signal, and the hydraulic pump 222 converts the hydraulic oil in the oil storage unit into the pressure oil and outputs the pressure oil to the reversing unit 23.

Specifically, the motor 223 is a source power of the whole device, is fixed at one end of the integrated block 221, is driven to rotate by two power lines introduced from the well, the hydraulic pump 222 is a pressure oil generating device, is fixed at the other end of the integrated block 221, is coaxial with the motor 223, and works under the driving of the motor to output pressure oil.

Referring to fig. 5-6, fig. 5 is a schematic structural diagram of a first end face of the integrated block; fig. 6 is a schematic structural view of the second end face of the integrated block. As shown in fig. 5 to 6, the integrated block 221 is an important component of the whole device, and has a circular structure, one end of which is fixed with a motor 223 and the other end is fixed with a hydraulic pump 222, and the two are kept coaxial, and the two are connected inside the integrated block 221. The inside of the integrated block 221 is crisscrossed with hydraulic oil ways, which are used for connecting the oil storage unit 21 and the hydraulic pump 222 on the one hand, so that the hydraulic oil in the oil storage unit 21 is continuously supplied to the hydraulic pump 222; the other side is used for outputting the pressure oil generated by the hydraulic pump 222 to the reversing unit 23 and simultaneously conveying the return oil of the reversing unit 23 back to the oil storage unit 21. Two notches Q are formed on the excircle of the integrated block, one notch Q is used for a hydraulic pump water pipe to pass through, so that water pumped and discharged by the hydraulic cylinder is conveniently conveyed to the well; the other for the passage of the line for powering the solenoid of the reversing unit 23 while transmitting the signal of the pressure detection unit 24 to the uphole equipment.

Specifically, the first end surface S1 is provided with a first through hole K1, an X1 oil hole and a T1 oil hole, the first through hole K1 extends from the first end surface S1 to the second end surface S2, the driving unit 22 further includes a connecting piece 224, the connecting piece 224 is disposed in the first through hole K1, the motor 223 is connected to the hydraulic pump 222 through the connecting piece 224, and the oil storage unit 21 is communicated with the X1 oil hole and the T1 oil hole; the second end surface S2 is provided with a P1 oil hole, a T2 oil hole, a P2 oil hole and an X2 oil hole, the P1 oil hole and the T2 oil hole are communicated with the reversing unit 23, and the P2 oil hole and the X2 oil hole are communicated with the hydraulic pump 222; after the hydraulic pump 222 sucks the hydraulic oil through the X2 oil hole and the X1 oil hole, the hydraulic oil is output to the reversing unit 23 through the P2 oil hole and the P1 oil hole, and return oil of the reversing unit 23 flows back to the oil storage unit 21 through the T2 oil hole and the T1 oil hole. Wherein, two oilholes in the bottom of oil storage bag communicate X1 oilhole and T1 oilhole respectively. In the present embodiment, the connection member 224 is a coupling, which is a preferred embodiment, to connect the motor 223 and the hydraulic pump 222.

The driving unit 22 further includes two pipe joints 225 and two bent pipes 226, the two pipe joints 225 are respectively installed on the P2 oil hole and the T2 oil hole, and the two pipe joints 225 are respectively communicated with the P3 oil hole and the T3 oil hole of the reversing unit 23 through the two bent pipes 226, wherein the bent pipes are made of stainless steel pipes.

In this embodiment, the integrated block 2 is further provided with process holes G1 and G2, and the process holes G1 and G2 are penetrated from top to bottom and are used for communicating with the oil holes on the two end surfaces S1 and S2. When the system works, hydraulic oil in the oil storage bag 4 flows into the X2 oil hole through the X1 oil hole and the G1 process hole, and then enters the hydraulic pump. The pressure oil generated by the hydraulic pump flows into the P1 oil hole through the P2 oil hole and the G2 process hole, then flows into the valve seat through the pipe joint and the bent pipe, and provides the pressure oil for the valve seat.

Still further, referring to fig. 7, fig. 7 is an oil path diagram of the valve seat. As shown in fig. 7 in combination with fig. 5, the reversing unit 23 includes: the valve seat 231 and the reversing valve 232, the valve seat 231 has two opposite side end faces S3 and S4, a P3 oil hole and a T3 oil hole are formed in one side end face S3, an A1 oil hole, a B1 oil hole and a C oil hole are formed in the other side end face S4, the T3 oil hole is communicated with the T2 oil hole, the P3 oil hole is communicated with the P1 oil hole, the pressure detecting unit 24 is mounted on the C oil hole, and the A1 oil hole and the B1 oil hole are correspondingly communicated with the first piston chamber and the second piston chamber; the reversing valve 232 is arranged on the top surface S5 of the valve seat 231 and is communicated with the valve seat 231, and the reversing valve 232 is electrically connected to the well electric control equipment; after the pressure oil flows into the reversing valve 232 through the P3 oil hole, the reversing valve 232 outputs the pressure oil to the A1 oil hole or the B1 oil hole according to the switching control signal, where the A1 oil hole and the B1 oil hole are the first oil outlet hole and the second oil outlet hole respectively;

the top surface S5 of the valve seat 231 is provided with a T4 oil hole, a P4 oil hole, an A2 oil hole and a B2 oil hole, as shown in fig. 10, the bottom surface of the reversing valve 232 is provided with a T5 oil hole, a P5 oil hole, an A3 oil hole and a B3 oil hole, and the T4 oil hole, the P4 oil hole, the A2 oil hole and the B2 oil hole are in one-to-one correspondence and are in alignment communication and sealing connection with the T5 oil hole, the P5 oil hole, the A3 oil hole and the B3 oil hole; the pressure oil flows into the reversing valve 232 through the P3 oil hole, the P4 oil hole and the P5 oil hole, and then is output to the A1 oil hole through the A3 oil hole and the A2 oil hole, or is output to the B1 oil hole through the B3 oil hole and the B2 oil hole; the return oil in the reversing valve 232 flows back to the T2 oil hole through the T5 oil hole, the T4 oil hole, and the T3 oil hole.

In this embodiment, the valve seat 231 further includes four process holes G3, G4, G5, G6, and G7, which are respectively disposed on the bottom surface S6 and the top surface S5 of the valve seat, the P3 port is communicated with P4 through the G6 process hole, the T3 port is communicated with T1 through the G4 process hole, the Y port is provided with the overflow valve 233, the bottom is communicated with G7, the A1 port is communicated with A2 through the G6 process hole, the B1 port is communicated with B2 through the G5 process hole, the C port is provided with the pressure sensor 10, and the bottom is communicated with G7. An oil discharge port is arranged in the middle of the overflow valve and is communicated with the T3 port through a G3 process hole. The pipe bending device comprises a P3 port and a T3 port, wherein the pipe bending device is communicated with a P2 port and a T2 port of the integrated block, and the A1 port and the B1 port are communicated with a first piston chamber and a second piston chamber of the hydraulic cylinder through hoses, and are connected with the external pipe joint 5. When the two electromagnetic coils of the reversing valve are electrified and disconnected, the oil way circulation of 'P2→A1, B1→T2' or 'P2→B1, A1→T2' can be realized. Thus, the pressure oil generated by the hydraulic pump can be transmitted to the hydraulic cylinder to drive the hydraulic cylinder to act, so as to perform water pumping and draining work.

In this embodiment, the reversing unit 23 further includes 4 pipe joints 234 respectively installed on the P3 oil hole, the T3 oil hole, the A1 oil hole and the B1 oil hole, and the two bent pipes 226 are respectively connected to the P3 oil hole, the T3 oil hole, and the A1 oil hole and the B1 oil hole through the pipe joints 234, and are respectively connected to the first piston chamber and the second piston chamber through the two pipe joints 234.

In this embodiment, the pressure detecting unit 24 is used as a preferred embodiment, and the pressure sensor is connected to the connection paths of the P3 oil hole and the P4 oil hole to collect the pressure value of the hydraulic oil, specifically, the pressure sensor is used to monitor the pressure value of the hydraulic oil in real time, determine the position of the piston of the hydraulic cylinder by determining the pressure change, and further control the on/off of two electromagnetic coils on the reversing valve 232, so that the pressure oil is continuously delivered to the A1 oil hole or the B1 oil hole of the valve seat, thereby realizing the continuous reciprocating motion of the piston of the hydraulic cylinder and achieving the purpose of draining water.

Still further, the reversing unit 23 further includes an overflow valve 233, the valve seat 231 is provided with the P3 oil hole and the end face of the T3 oil hole is further provided with a Y oil hole, the overflow valve 233 is installed on the Y oil hole and is electrically connected to the above-well electric control device, the above-well electric control device monitors the system pressure of the hydraulic power device according to the pressure signal, when the pressure value exceeds a threshold value, the above-well electric control device outputs a pressure limiting signal to the overflow valve 233, and the overflow valve 233 works according to the pressure limiting signal, thereby effectively controlling the highest pressure of the pressure oil and protecting the whole device. In this embodiment, the relief valve 233 is connected to the connection path between the P3 oil hole and the P4 oil hole.

In an embodiment of the application, the relief valve is a cartridge-type relief valve.

Further, the hydraulic power device further includes a housing 25 having an accommodating space and two open ends communicating with the accommodating space, and the oil storage unit 21, the driving unit 22, the reversing unit 23 and the pressure detecting unit 24 are installed in the accommodating space. In this embodiment, the housing 25 is made of aluminum pipe and has protection and connection functions. After the parts are assembled and tested to be qualified, the parts are integrally installed into the shell 25 for protection, meanwhile, the shell 25 also plays a role of connection transition, one end of the shell is connected with a multi-core pipeline, and the other end of the shell is connected with a hydraulic cylinder.

Referring to fig. 8, fig. 8 is a flowchart of a control method according to the present application. As shown in fig. 8, a hydraulic cylinder control method of the present application is applied to the hydraulic power unit described in any one of the above, and includes:

step S1: the hydraulic oil of the oil storage unit is converted into pressure oil by the driving unit according to a starting signal output by the on-well electronic control equipment and is output to the reversing unit;

step S2: the reversing unit correspondingly outputs the pressure oil to a first piston chamber or a second piston chamber of the hydraulic cylinder through a first oil outlet or a second oil outlet so as to drive the hydraulic cylinder to work;

step S3: the pressure value of the pressure oil is acquired in real time through a pressure detection unit, and then a pressure signal is output to the on-well electronic control equipment;

step S4: and outputting the switching control signal to the reversing unit through the aboveground electric control equipment according to the pressure signal, wherein the reversing unit selects to correspondingly output the pressure oil output by the driving unit to the second piston chamber or the first piston chamber through the second oil outlet or the first oil outlet according to the switching control signal so as to drive the hydraulic cylinder to perform reversing operation.

Specifically, when the hydraulic power device of the hydraulic cylinder under the coal bed gas well is used, one end of the hydraulic power device is connected with the multi-core pipeline, and the other end of the hydraulic power device is connected with the hydraulic cylinder, as shown in fig. 9. The water pipe in the multicore pipeline passes through the notch on the integrated block in the hydraulic power device and is connected with the water outlet on the hydraulic cylinder, and is used for conveying the water pumped and discharged by the hydraulic cylinder to the well. The power line in the multi-core pipeline is directly connected with the motor to supply power to the motor. The control circuit and the signal circuit pass through another notch on the integrated block and are respectively connected with the electromagnetic coil and the pressure sensor on the reversing valve, and are used for controlling the reversing valve to reverse and transmitting signals detected by the pressure sensor back to the on-well electronic control equipment. After the assembly is completed according to fig. 3, the assembly is put into a coal bed gas well by using an aboveground injection device, after the assembly reaches a preset position, various circuits in a multicore pipeline are communicated with an aboveground electric control device, a motor is powered, the motor rotates to drive a hydraulic pump to generate pressure oil, any electromagnetic coil of a reversing valve is electrified, the pressure oil enters a hydraulic cylinder through the reversing valve to drive a piston of the hydraulic cylinder to move for pumping and draining water, after the unidirectional movement of the piston is finished, the pressure sensor transmits a pressure signal back to the aboveground electric control device, after the equipment receives a high-pressure signal, the device switches a control signal to electrify another coil of the reversing valve, the pressure oil enters another cavity of the hydraulic cylinder after the reversing valve reverses, the hydraulic cylinder piston is driven to reversely move for pumping and draining water, after the reversing movement of the piston is finished, the system pressure rises, the pressure sensor transmits the pressure signal back to the aboveground electric control device, and after the device receives the high-pressure signal, the control signal is electrified to another coil of the reversing valve, and the hydraulic cylinder is driven to reverse, so that the circulating reciprocating pumping and draining water action is realized.

In summary, the application has the following advantages: according to the application, the driving unit, the oil storage unit and the reversing unit are arranged underground, and the underground hydraulic cylinder is directly driven to work after pressure oil is generated, so that the original technical problem is thoroughly solved; meanwhile, a hydraulic pump station is not required to be arranged on the well, two hydraulic oil pipes in the multi-core pipeline are omitted, correspondingly, two circuits are replaced, one circuit is used for the positive electrode and the negative electrode of the motor, and the other circuit is used for a signal circuit of the pressure sensor, so that the overall dimension of the multi-core pipeline is greatly reduced, the weight of the pipeline is reduced by more than 80%, and the load is well reduced for the well facilities and conveying equipment; meanwhile, the reversing valve drives the hydraulic cylinder to reverse, so that the abrasion of the motor is reduced, and the production cost is reduced.

Although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. A hydraulic power unit for a hydraulic cylinder in a coal bed methane well, comprising:

an oil storage unit which accommodates hydraulic oil;

the driving unit is electrically connected with the aboveground electric control equipment and converts the hydraulic oil into pressure oil to be output after receiving a starting signal output by the aboveground electric control equipment;

the reversing unit is communicated with the driving unit and is provided with a first oil outlet and a second oil outlet, and the reversing unit is correspondingly communicated with a first piston chamber and a second piston chamber of a hydraulic cylinder through the first oil outlet and the second oil outlet respectively;

the pressure detection unit is arranged on the reversing unit and is electrically connected with the well electric control equipment, and the pressure detection unit is used for outputting a pressure signal after detecting the pressure value of the pressure oil;

the above-well electric control equipment outputs a switching control signal to the reversing unit according to the pressure signal, and the reversing unit selects to correspondingly output the pressure oil output by the driving unit to the first piston chamber or the second piston chamber through the first oil outlet or the second oil outlet according to the switching control signal so as to drive the hydraulic cylinder to perform reversing operation.

2. The hydraulic power unit of claim 1, wherein the drive unit comprises:

the integrated block is provided with a first end face and a second end face which are oppositely arranged, and the oil storage unit is arranged on the first end face;

the hydraulic pump is arranged on the second end face of the integrated block and is communicated with the reversing unit;

the motor is arranged on the first end face and connected with the hydraulic pump, the motor drives the hydraulic pump to work according to the starting signal, and the hydraulic pump converts hydraulic oil in the oil storage unit into pressure oil and outputs the pressure oil to the reversing unit.

3. The hydraulic power unit according to claim 2, wherein a first through hole, an X1 oil hole and a T1 oil hole are formed in the first end face, the first through hole extends from the first end face to the second end face, the driving unit further includes a connecting member provided in the first through hole, the motor is connected to the hydraulic pump through the connecting member, and the oil storage unit is communicated with the X1 oil hole and the T1 oil hole;

the second end face is provided with a P1 oil hole, a T2 oil hole, a P2 oil hole and an X2 oil hole, the P1 oil hole and the T2 oil hole are communicated with the reversing unit, and the P2 oil hole and the X2 oil hole are communicated with the hydraulic pump;

after the hydraulic pump sucks hydraulic oil through the X2 oil hole and the X1 oil hole, the hydraulic pump outputs pressure oil to the reversing unit through the P2 oil hole and the P1 oil hole, and return oil of the reversing unit flows back to the oil storage unit through the T2 oil hole and the T1 oil hole.

4. A hydraulic power unit as claimed in claim 3, wherein the reversing unit comprises:

the valve seat is provided with two opposite side end surfaces, a P3 oil hole and a T3 oil hole are formed in one side end surface of the valve seat, an A1 oil hole, a B1 oil hole and a C oil hole are formed in the other side end surface of the valve seat, the T3 oil hole is communicated with the T2 oil hole, the P3 oil hole is communicated with the P1 oil hole, the pressure detection unit is arranged on the C oil hole, and the A1 oil hole and the B1 oil hole are correspondingly communicated with the first piston chamber and the second piston chamber;

the reversing valve is arranged on the top surface of the valve seat and is communicated with the valve seat, and the reversing valve is electrically connected with the uphole electric control equipment;

after the pressure oil flows into the reversing valve through the P3 oil hole, the reversing valve outputs the pressure oil to the A1 oil hole or the B1 oil hole according to the switching control signal, wherein the A1 oil hole and the B1 oil hole are the first oil outlet hole and the second oil outlet hole respectively.

5. The hydraulic power unit according to claim 4, wherein a T4 oil hole, a P4 oil hole, an A2 oil hole and a B2 oil hole are formed in the top surface of the valve seat, a T5 oil hole, a P5 oil hole, an A3 oil hole and a B3 oil hole are formed in the bottom surface of the reversing valve, and the T4 oil hole, the P4 oil hole, the A2 oil hole and the B2 oil hole are in one-to-one correspondence and are in alignment communication with the T5 oil hole, the P5 oil hole, the A3 oil hole and the B3 oil hole;

the pressure oil flows into the reversing valve through the P3 oil hole, the P4 oil hole and the P5 oil hole and then is output to the A1 oil hole through the A3 oil hole and the A2 oil hole, or is output to the B1 oil hole through the B3 oil hole and the B2 oil hole;

the return oil in the reversing valve flows back to the T2 oil hole through the T5 oil hole, the T4 oil hole and the T3 oil hole.

6. The hydraulic power unit according to claim 5, wherein the pressure detecting unit is connected to a connection path of the P3 oil hole and the P4 oil hole to collect a pressure value of the hydraulic oil.

7. The hydraulic power unit according to claim 5, wherein the reversing unit further comprises an overflow valve, the valve seat is provided with the P3 oil hole and the end face of the T3 oil hole is further provided with a Y oil hole, the overflow valve is arranged on the Y oil hole and is electrically connected to the on-well electronic control device, the on-well electronic control device monitors the system pressure of the hydraulic power unit according to the pressure signal, when the pressure value exceeds a threshold value, the on-well electronic control device outputs a pressure limiting signal to the overflow valve, and the overflow valve works according to the pressure limiting signal.

8. The hydraulic power unit according to claim 7, wherein the relief valve is connected to a connecting passage of the P3 oil hole and the P4 oil hole.

9. The hydraulic power unit according to claim 1, further comprising a housing having a receiving space and two open ends communicating with the receiving space, wherein the oil storage unit, the reversing unit, and the pressure detection unit are installed in the receiving space.

10. A hydraulic cylinder control method, characterized by being applied to the hydraulic power unit as recited in any one of the above claims 1 to 9, comprising:

the hydraulic oil of the oil storage unit is converted into pressure oil by the driving unit according to a starting signal output by the on-well electronic control equipment and is output to the reversing unit;

the reversing unit correspondingly outputs the pressure oil to a first piston chamber or a second piston chamber of the hydraulic cylinder through a first oil outlet or a second oil outlet so as to drive the hydraulic cylinder to work;

the pressure value of the pressure oil is acquired in real time through a pressure detection unit, and then a pressure signal is output to the on-well electronic control equipment;

and outputting the switching control signal to the reversing unit through the aboveground electric control equipment according to the pressure signal, wherein the reversing unit selects to correspondingly output the pressure oil output by the driving unit to the second piston chamber or the first piston chamber through the second oil outlet or the first oil outlet according to the switching control signal so as to drive the hydraulic cylinder to perform reversing operation.