Novel automatic diverter valve and working method thereof

Abstract

The invention relates to a novel automatic diverter valve and a method. The valve group mainly solves the problem that an existing valve group cannot conduct forward well washing on the underground through an oil pipe. The device is characterized in that the lower shell is connected with an oil pipe; the upper shell is connected with a middle joint; the upper end of the middle joint is connected with an oil pipe; a bypass hole is laterally formed in the middle connector, an upper spigot is arranged on the upper portion of the middle connector, and an integrated valve element is arranged in a lower shell. The integrated valve element body comprises two check valves, and a liquid inlet is formed in the lower end of the structural check valve body. A check valve is arranged at an upper step of the structural check valve, and a cover plate is arranged at a groove formed in the upper end of the step of the structural check valve; and the upper port of the structural check valve is connected with a hollow sealing pipe. According to the diverter valve, communication during production of an underground development pipe column is guaranteed, well fluid in an oil pipe flows into an annular space of an oil sleeve through the bypass hole when a well is shut down, forward well washing is achieved through the bypass hole when measures are taken, and meanwhile the well fluid or well washing fluid can be prevented from flowing through underground oil extraction equipment when the oil extraction equipment is shut down or the well is washed.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum mechanical equipment, and in particular to a novel automatic diverter valve and a working method thereof. Background Art

[0002] In the mechanical oil production process, the existing technology is realized by a combination of a check valve and an oil unloading valve. The check valve is installed at the first oil pipe coupling on the development equipment, and the oil unloading valve is installed at the second oil pipe coupling.

[0003] During production, the high-pressure well fluid in the well pushes the check valve core upward, and the entire pipe string is connected for normal production; when shutting down, the check valve falls under the action of gravity, and the well fluid is sealed in the oil pipe. When the oil drain valve is in operation, a rod is thrown downward from the wellhead to smash the oil unloading valve (one-time), and the well fluid flows back to the bottom of the well through the oil unloading hole of the oil unloading valve.

[0004] The disadvantages of this combination of check valve and oil unloading valve are: first, after multiple starts and stops, solid particles in the well fluid will accumulate above the check valve, causing problems such as increased starting load and difficulty in starting the electric pump unit. Second, the oil unloading valve is connected to the bottom of the well once and can only be used during operations, and forward well washing cannot be achieved. Third, the single hole of the oil unloading valve is easily blocked by particles and the well fluid cannot be discharged normally. When the pipe string is pulled out, a large amount of well fluid will be carried to pollute the well site. Summary of the invention

[0005] The technical problem to be solved by the present invention is to solve the problems existing in the background technology, and to provide a new type of automatic diverter valve, which realizes the functions of the existing check valve and oil unloading valve combination, ensures the connectivity of the downhole development pipe string during production, realizes forward well washing during measures, and also prevents the well fluid or well washing fluid from flowing through the downhole oil production equipment when the oil production equipment is shut down or when washing the well. The present invention also provides a working method of the automatic diverter valve.

[0006] The present invention can solve the problem through the following technical solution: the new automatic diverter valve comprises a housing, the housing is divided into an upper housing and a lower housing; the lower housing is connected to the oil pipe through a thread; the upper housing is threadedly connected to the middle joint; the upper end of the middle joint is connected to the oil pipe through a thread; The middle joint has two bypass holes on the side, and an upper stop is provided at the center of the middle joint above the bypass hole; an integrated valve core is installed in the housing below the upper stop of the middle joint; The integrated valve core body includes two check valves, namely a lower structural check valve and an upper check valve. A liquid inlet is provided at the lower end of the structural check valve body; a check valve is provided on the upper step of the structural check valve, a groove is provided on the upper end of the step of the structural check valve, a cover plate is installed on the groove, and the upper end port of the structural check valve is threadedly connected to a hollow sealing tube; an elastic member is installed on the outside of the hollow sealing tube.

[0007] Furthermore, the elastic member outside the hollow sealing tube is a return spring; the lower end of the return spring abuts against the upper end surface of the structural check valve, and the upper end abuts against the lower end surface of the middle joint.

[0008] Furthermore, the upper end of the one-flow valve is a cylindrical main body, and the middle part of the lower end is arranged as a tapered tip which is larger at the top and smaller at the bottom.

[0009] Furthermore, the cover plate is provided with a plurality of liquid holes.

[0010] Furthermore, the distance between the check valve and the cover plate is 20-30 mm.

[0011] The upper end of the hollow sealing tube is sleeved with two upper and lower spacer rings, and the spacing between the spacer rings is greater than the diameter of the bypass hole; when the hollow sealing tube moves up to the upper stop, the spacer rings are respectively located between the hollow sealing tube and the upper and lower bypass holes.

[0012] The present invention also provides a novel working method of an automatic diverter valve, comprising the following steps: Step 1: When the electric pump is started, the well fluid is pressurized by the electric pump and flows upward through the oil pipe into the lower housing. Since the lower housing and the integrated valve core are closed by the structural check valve, the well fluid pushes the integrated valve core to move upward. During the upward movement of the integrated valve core, the well fluid enters the integrated valve core, pushes the upper check valve upward, flows into the oil pipe connected to the automatic diverter valve through the middle cavity, and then lifts it to the ground. Step 2: When the electric pump is turned off, the upper check valve on the integrated valve core drops down, blocking the well fluid in the oil pipe from flowing back into the electric pump. Under the gravity of the well fluid and the integrated valve core, the integrated valve core moves down to the initial position to allow the check valve to work and perform secondary sealing to prevent the well fluid in the upper oil pipe from flowing back. After the integrated valve core moves down, the bypass port of the middle joint opens, and the well fluid flows from the oil pipe into the annular space, balancing the internal and external pressures.

[0013] Compared with the above background technology, the present invention has the following beneficial effects: 1. The integrated valve core design can automatically adjust the working state of the automatic diverter valve according to the changes in downhole working conditions, ensuring multiple connections and closures between the submersible electric pump unit and the oil pipe, and more flexible development and measures.

[0014] 2. It solves the problem of forward well washing, prevents wet pipe operation from polluting the well site during pumping, and can also perform well pressure circulation on gas-bearing wells.

[0015] 3. The integrated valve core simplifies the check valve design and ensures the stability of the connection during operation; the double-layer check valve structure, the upper check valve can provide gravity reset to ensure that the well fluid in the oil pipe will not flow back into the pump; the combination of mechanical seal, structural seal and radial seal ensures the effectiveness of the seal under multiple opening and closing conditions, avoids liquid leakage and ensures the efficient operation of the development system; the dual structure combining gravity reset and mechanical reset also realizes the righting function, ensuring that the internal integrated valve core falls back to the sealing position in the center when the well is shut down.

[0016] 4. The bypass hole adopts radial and axial multiple sealing design to prevent the loss of high-pressure well fluid through the oil unloading hole and ensure the overall development efficiency.

[0017] 5. Two upper and lower spacer rings are sleeved on the upper end of the hollow sealing tube, and the spacing between the spacer rings is greater than the diameter of the bypass hole; when the hollow sealing tube moves up to the upper stop, the spacer rings are respectively located between the hollow sealing tube and the upper and lower bypass holes to avoid lateral leakage and play a contact sealing role.

[0018] The invention combines the advantages of a check valve and an oil unloading valve, and adopts a double valve structure to adjust the connection mode between the pipe column and the bottom of the well. The original one-time mechanical destruction is adjusted to an integrated valve core, and the working state is adjusted according to the change of well fluid pressure caused by the working conditions, so that the well fluid or well washing fluid does not flow through the downhole oil production equipment, and the positive well washing function can also be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Attached Figure 1 is a schematic diagram of the device for closing an oil well according to the present invention; Attached Figure 2 is a schematic diagram of the device of the present invention during oil well production; Attached Figure 3 is a schematic diagram of a housing of the device of the present invention; Attached Figure 4 is a schematic diagram of the middle joint of the device of the present invention; Attached Figure 5 It is a schematic diagram of the integrated valve core of the device of the present invention.

[0020] In the figure: 1. housing; 2. middle joint; 21. bypass hole; 22. upper stop; 3. integrated valve core; 31. liquid inlet; 32. check valve; 33. cover plate; 34. return spring; 35. hollow sealing tube; 36. structural check valve. Specific implementation method: The present invention will be further described below in conjunction with the accompanying drawings: As attached Figure 1 , Figure 3As shown, the new automatic diverter valve includes a housing 1; the housing 1 is divided into an upper housing and a lower housing; the lower housing is connected to the oil pipe through a thread; the upper housing is threadedly connected to the middle joint 2; the upper end of the middle joint 2 is connected to the oil pipe through a thread.

[0022] like Figure 4 As shown, the middle joint 2 has two bypass holes 21 on the side, and an upper stop 22 is provided at the center of the middle joint 2 above the bypass hole 21; an integrated valve core 3 is installed in the lower shell 1 below the upper stop 22 of the middle joint, and the bottom of the integrated valve core 3 is placed at the lower step of the inner cavity of the shell 1.

[0023] like Figure 5 As shown, the integrated valve core body includes two check valves, namely a structural check valve 36 at the bottom and a check valve 32 at the top, the structural check valve 36 body having a liquid inlet 31 at the bottom; the structural check valve 36 has a check valve 32 at the upper step, the upper end of the check valve 32 is a cylindrical body, and the middle of the lower end is a tapered tip that is larger at the top and smaller at the bottom; the upper end of the step of the structural check valve 3 is provided with a groove, and a cover plate 33 is installed at the groove, and a plurality of liquid holes are opened on the cover plate 33; the upper end port of the structural check valve 36 is threadedly connected to a hollow sealing tube 35; a reset spring 34 is installed on the outside of the hollow sealing tube 35; the lower end of the reset spring 34 abuts against the upper end face of the structural check valve 36, and the upper end abuts against the lower end face of the middle joint 2.

[0024] The distance between the check valve 32 and the cover plate is 20-30 mm, which is convenient for the well fluid to flush the cover plate. After the cover plate is lifted, the liquid can flow out from the side of the cover plate. The inner cavity of the structural check valve 36 and the check valve 32 are both tapered reducers.

[0025] The upper end of the hollow sealing tube is sleeved with two upper and lower spacer rings, and the spacing between the spacer rings is greater than the diameter of the bypass hole; when the hollow sealing tube moves up to the upper stop, the spacer rings are respectively located between the hollow sealing tube and the upper and lower bypass holes.

[0026] The housing of the new automatic diverter valve is connected to the oil pipe through the lower thread, and contains an integrated valve core part, which provides connection and support for the entire diverter valve; the middle joint connects the lower housing and the oil pipe, and provides a limit and bypass hole for the integrated valve core when it is working. The integrated valve core is the main working part of the automatic diverter valve, which is divided into a structural check valve at the lower end. After the lower end falls into place, the lateral bypass port is closed by the inner wall of the lower housing and opens after the upper end moves up; the upper check valve, which opens and closes the liquid flow channel through the integrated valve core moving up and down under the push of the liquid; the cover plate limits the valve core of the upper check valve.

[0027] The working process of the new automatic diverter valve is: 1. When the electric pump is started, the well fluid is pressurized by the electric pump and flows upward through the oil pipe into the lower housing. Since the lower housing and the integrated valve core are closed by the structural check valve, the well fluid pushes the integrated valve core to move upward; during the upward movement of the integrated valve core, the inner diameter of the lower housing becomes larger and the structural check valve fails. The well fluid enters the integrated valve core, pushing the upper check valve upward, and flows into the oil pipe connected to the automatic diverter valve through the middle cavity, and then lifts it to the ground.

[0028] 2. When the electric pump is turned off, the upper check valve on the integrated valve core falls down, blocking the well fluid in the oil pipe from flowing back into the electric pump. Under the gravity of the well fluid and the integrated valve core, the integrated valve core moves down to the initial position to structure the check valve to work and perform secondary sealing to prevent the well fluid from flowing back from the upper oil pipe. After the integrated valve core moves down, the bypass port of the middle joint opens, and the well fluid flows from the oil pipe into the annular space, balancing the internal and external pressures.

[0029] Example 1 The integrated diverter valve can automatically adjust the connection mode according to the change of downhole pressure. When the mechanical mining equipment is started, the mechanical mining equipment and the oil pipe are connected to achieve normal production; when there is no mechanical mining equipment, the oil pipe and the casing annulus are connected to facilitate users to perform forward well washing or self-flowing. In oil wells with self-flowing potential, self-flowing can be started first, and the mechanical mining equipment can be started for production when the formation pressure is insufficient. Compared with the previous mechanical check valve, the integrated check valve is more intelligent in operation, and users are more flexible and diverse in choosing oil well development methods.

[0030] like Figure 1 As shown in the figure, when the electric pump is started, the well fluid enters the lower housing through the oil pipe after being pressurized by the pump. The integrated valve core is pushed upward as a whole by the upper and lower pressure difference of the bottom structural check valve. The lateral liquid inlet of the bottom structural check valve gradually opens during the upward movement, and the well fluid enters the inside of the integrated valve core (hollow cavity) through the lateral liquid inlet. The well fluid continues to flow upward, pushing the upper check valve upward, and the internal channel of the automatic diverter valve is fully opened, connecting the upper and lower oil pipes to lift the well fluid from the bottom of the well to the ground to achieve normal production. When the integrated valve core moves upward to the upper sealing stop, the overall integrated valve core will stop moving upward. The pressure will decrease during the flow of high-pressure liquid, so a pressure difference will be formed between the upper and lower check valves of the bottom, so that the bottom check valve can be stabilized at the upper stop position. The pressure seal between the middle seal pipe and the upper stop, and the contact seal between the middle seal pipe and the middle joint prevent the well fluid from flowing into the annulus, ensuring the working efficiency of the unit.

[0031] In order to achieve the connection between the oil pipe and the bottom of the well, two bypass holes 21 are reserved on the middle joint, and the bypass holes 21 are opened and closed by moving the integrated valve core up and down. The opening and closing of the automatic bypass hole 21 is achieved by the downhole high-pressure well fluid, so it can be opened repeatedly, which can better cooperate with the single well development method.

[0032] like Figure 2 As shown, when the electric pump is shut down, high-pressure liquid cannot be provided underground, and the well fluid in the oil pipe begins to flow downward due to gravity. At this time, the upper check valve falls first, closing the connection between the oil pipe and the electric pump pipe to prevent the liquid and solid particles in the oil pipe from flowing back into the pump. This can prevent the accumulation of solid particles in the pump, and also prevent pump reversal and related problems caused by liquid reflux. After the upper check valve is closed, the gravity of the well fluid in the oil pipe completely acts on the integrated movable valve core, and the integrated movable valve core moves downward quickly with the help of the well fluid pressure and its own gravity, thereby closing the bottom structural check valve 36.

[0033] In order to enhance the stability of equipment operation, a reset spring is added to the outside of the sealing tube to provide overall straightening during the falling process of the integrated valve core, and also provide a downward reset thrust. A two-way multiple sealing method is adopted at the bypass hole to prevent the leakage of high-pressure well fluid through the bypass hole and reduce the overall development efficiency. A composite material contact surface mechanical seal is used between the upper end face of the hollow sealing tube and the upper stop; at the same time, between the hollow sealing tube and the inner wall of the automatic diverter valve housing, two spacer rings are sleeved on the outer wall of the hollow sealing tube. When the hollow sealing tube moves up to the upper stop, the spacer rings are respectively located between the hollow sealing tube and the upper and lower bypass holes to avoid lateral leakage and play a contact sealing role.

Claims

1. A novel automatic diverter valve, comprising a housing (1), characterized in that: The housing (1) is divided into an upper housing and a lower housing; the lower housing is connected to the oil pipe via a thread; the upper housing is threadedly connected to the middle joint (2); the upper end of the middle joint (2) is connected to the oil pipe via a thread; The middle joint (2) has two bypass holes (21) formed on the side thereof, and an upper stopper (22) is provided at the center of the middle joint (2) above the bypass holes (21); an integrated valve core (3) is installed in the housing (1) below the upper stopper (22); The integrated valve core body comprises two check valves, namely a lower structural check valve (36) and an upper check valve (32). The lower end of the structural check valve (36) body is provided with a liquid inlet (31); the check valve (32) is disposed on a step portion of an upper portion of the structural check valve (36); a groove is disposed on an upper end of the step portion of the structural check valve (36), and a cover plate (33) is mounted on the groove.

2. The new automatic diverter valve according to claim 1 is characterized in that: The upper end port of the structural check valve (36) is threadedly connected to the hollow sealing tube (35).

3. The new automatic diverter valve according to claim 2 is characterized in that: An elastic member is installed outside the hollow sealing tube (35).

4. The new automatic diverter valve according to claim 3 is characterized in that: The elastic member is a return spring; the lower end of the return spring abuts against the upper end surface of the structural check valve, and the upper end abuts against the lower end surface of the middle joint.

5. The new automatic diverter valve according to claim 1 is characterized in that: The check valve (32) has a cylindrical main body at the upper end and a tapered tip at the middle of the lower end that is larger at the top and smaller at the bottom; the inner cavity of the check valve (32) has a tapered structure.

6. The new automatic diverter valve according to claim 1 is characterized in that: The cover plate (33) is provided with a plurality of liquid holes.

7. The new automatic diverter valve according to claim 6 is characterized in that: The distance between the check valve (32) and the cover plate is 20-30 mm.

8. The new automatic diverter valve according to claim 2 is characterized in that: A sealing gasket is arranged between the upper end surface and the upper stop of the hollow sealing tube.

9. The new automatic diverter valve according to claim 8 is characterized in that: The upper end of the hollow sealing tube is sleeved with two upper and lower spacer rings, and the spacing between the spacer rings is greater than the diameter of the bypass hole; when the hollow sealing tube moves up to the upper stop, the spacer rings are respectively located between the hollow sealing tube and the upper and lower bypass holes.

10. A method for operating the new automatic diverter valve according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: When the electric pump is started, the well fluid is pressurized by the electric pump and flows upward through the oil pipe into the lower housing; the lower housing and the integrated valve core are closed by a structural check valve, and the well fluid pushes the integrated valve core upward; During the upward movement of the integrated valve core, the well fluid enters the integrated valve core, pushes the check valve upward, flows into the oil pipe connected to the automatic diverter valve through the middle cavity of the automatic diverter valve, and then is lifted to the ground; Step 2: When the electric pump is turned off, the upper check valve on the integrated valve core drops down, sealing the well fluid in the oil pipe so that it cannot flow back into the electric pump. Under the gravity of the well fluid and the integrated valve core, the integrated valve core moves down to its initial position, and the structural check valve works to perform secondary sealing to prevent the well fluid in the upper oil pipe from flowing back. At the same time, after the integrated valve core moves down, the bypass port of the middle joint opens, and the well fluid flows from the oil pipe into the casing annulus through the bypass port, balancing the internal and external pressures.

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