Fixed gas lift workstring for snubbing

Abstract

The present application relates to oil and gas field production mining equipment technical field, it is a kind of fixed gas lift working barrel for operating under pressure, including working barrel body, sleeve pressure operation valve, one-way valve head and piston assembly, working barrel body upper end left and right interval is provided with the flow-through channel and gas lift channel that pass through up and down, working barrel body lower part is provided with the flow-through hole that is connected with gas lift channel and flow-through channel.The present application is reasonable and compact, easy to use, by setting piston assembly, the pressure of liquid in annulus between the outside of working barrel body and the inside of wellbore can be changed to make piston assembly move downward, the communication and isolation of flow-through hole and annulus are realized by the change of piston assembly position, by such setting, the difficulty of installing rupture disc and plug for each working barrel body is reduced when working barrel body operates under pressure, the operation is simpler and safer, the operation efficiency is improved, the production cost is reduced, and the phenomenon of pollution wellbore can also be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas field production mining equipment, and is a fixed gas lift working barrel for snubbing operation. BACKGROUND

[0002] In oil and gas field production, a pipe string is often run in and out, in order to ensure operation safety, liquid needs to be injected to pressurize the well, and after well pressure is built up, damage to the reservoir cannot be repaired, which seriously affects the recovery of oil and gas resources.

[0003] Snubbing operation of running in and out of the pipe string can avoid damage to the reservoir, and has been widely used. However, when the pipe string with a gas lift valve is run in, according to the principle of the gas lift valve, the gas lift valve will open under the action of high pressure fluid in the wellbore, so that the high pressure fluid enters the inner cavity of the pipe string, and a leakage accident occurs. The current solution is to install a rupture disc on each level of the gas lift working barrel, the rupture disc reversely bears a pressure of 50 MPa or more, and normally bears a pressure difference of 7 to 15 MPa. Even if the gas lift valve opens during running in, effective sealing of the pipe string can be achieved, and by normal injection of liquid or gas, the rupture discs at all levels can be broken, and normal production of the oil and gas well can be realized. Since a set of rupture discs needs to be installed on each level of the gas lift valve working barrel, the cost is high. The rupture disc is made of ceramic material, which is easy to accumulate in the wellbore, causing risks to subsequent wireline operations. In addition, when the pipe string needs to be pulled out, a set of tubing internal plug needs to be installed on each level of the fixed gas lift valve working barrel, which makes the operation difficult, and the tool and operation cost is high. SUMMARY

[0004] The present application provides a fixed gas lift working barrel for snubbing operation, which overcomes the shortcomings of the prior art, and effectively solves the problems of difficult operation and high operation cost of the existing fixed working barrel.

[0005] The technical scheme of the present application is realized by the following measures: a fixed gas lift working barrel for snubbing operation, comprising a working barrel body, a sleeve pressure operation valve, a check valve head and a piston assembly, an upper and lower through flow passage and a gas lift passage are arranged on the upper end of the working barrel body in a spaced manner, a flow passage is arranged on the lower part of the working barrel body and communicates with the gas lift passage and the flow passage, a sleeve pressure operation valve is fixedly installed on the inner side of the upper part of the gas lift passage corresponding to the position above the flow passage, a check valve head is installed on the inner side of the middle part of the gas lift passage, and the upper end of the check valve head is in sealing contact with the outlet of the sleeve pressure operation valve, the inner side of the lower part of the gas lift passage and the outer side of the piston assembly are sealingly installed together, the upper end of the piston assembly abuts against the lower end of the check valve head, and the upper end of the check valve head can be connected to the flow passage and the outlet of the sleeve pressure operation valve after moving downward.

[0006] The following is a further optimization or / and improvement of the above-mentioned technical scheme of the application:

[0007] The piston assembly can include a piston rod, a first shear pin, a second shear pin, a locking sleeve and a supporting sleeve, an inner ring table is fixed on the inner side of the gas lift passage corresponding to the position above the overflow hole, a sealing sleeve is sleeved on the inner ring table, the upper end of the piston rod abuts against the lower end of the single-way valve head and makes the upper end of the single-way valve head close the outlet of the sleeve-operated valve, a sealing ring table is fixed on the outer side of the lower end of the piston rod corresponding to the position below the overflow hole, the lower end of the sealing ring table is fixed with a push-pull rod in the center, the first shear pin is fixed and installed on the inner side of the right part of the gas lift passage corresponding to the position below the sealing ring table, the second shear pin is fixed and installed on the inner side of the gas lift passage corresponding to the position below the first shear pin, the supporting sleeve is fixed and installed on the inner side of the lower part of the gas lift passage corresponding to the position below the second shear pin, the inner side of the supporting sleeve is tapered from small to large, the locking sleeve is installed between the inner side of the supporting sleeve and the outer side of the push-pull rod, the upper outer side of the locking sleeve matches the inner side of the supporting sleeve, and the locking sleeve can prevent the push-pull rod from moving upward.

[0008] The piston assembly can further include a pressing sleeve, the pressing sleeve is screwed on the inner side of the gas lift passage corresponding to the position below the supporting sleeve, the upper inner side of the pressing sleeve is provided with a first connecting hole, a second connecting hole and a third connecting hole which are sequentially communicated from top to bottom, the inner diameter of the first connecting hole is not less than the inner diameter of the lower end of the supporting sleeve, the inner diameter of the second connecting hole is between the inner diameter of the first connecting hole and the outer diameter of the push-pull rod, and the projection of the third connecting hole on the horizontal plane is located on the projection of the second connecting hole on the horizontal plane.

[0009] The third connecting hole can be a regular polygon in cross section.

[0010] The outer side of the push-pull rod can be provided with a plurality of tapered locking ring tables which are spaced apart from top to bottom and large at the top and small at the bottom, and the inner side of the locking sleeve is provided with a plurality of tapered ring grooves which are spaced apart from top to bottom and match the locking ring tables.

[0011] The outer side of the piston rod corresponding to the position below the inner ring table can be fixed with a limiting ring table located above the sealing ring table.

[0012] At least two sealing elements can be uniformly distributed between the outer side of the piston rod and the inner side of the inner ring table and between the upper outer side of the sealing ring table and the inner side of the gas lift passage.

[0013] The single-way valve head can include a first valve head, a second valve head and an elastic reset member, the first valve head and the second valve head are symmetrically installed on the inner side of the gas lift passage corresponding to the position above the inner ring table, the elastic reset member is installed between the lower part of the first valve head and the lower part of the second valve head, the upper outer side of the first valve head is in the shape of a spherical cap, the upper outer side of the first valve head abuts against the inner side of the outlet of the sleeve-operated valve, and the lower end of the second valve head abuts against the upper end of the piston rod.

[0014] The application has reasonable and compact structure, is convenient to use, the piston assembly is arranged, the pressure of liquid in the annulus between the outside of the working barrel body and the wellbore is changed to make the piston assembly move downward, the communication and the isolation of the overflow hole and the annulus are realized through the change of the position of the piston assembly, through the arrangement, the difficulty of installing the rupture disc and the plug in each working barrel body is reduced when the working barrel body is operated under pressure, the operation is simpler and safer, the operation efficiency is improved, the production cost is reduced, and the phenomenon of polluting the wellbore is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0015] BRIEF DESCRIPTION OF DRAWINGS Figure 1 It is a schematic view of the front sectional structure of the embodiment one.

[0016] BRIEF DESCRIPTION OF DRAWINGS Figure 2 It is a schematic view of the enlarged structure at A in the embodiment one. Figure 1

[0017] The codes in the drawings are as follows: 1 is a working barrel body, 2 is a sleeve pressure operation valve, 3 is an overflow passage, 4 is a gas lift passage, 5 is an overflow hole, 6 is a piston rod, 7 is a first shear pin, 8 is a second shear pin, 9 is a locking sleeve, 10 is a supporting sleeve, 11 is an inner ring table, 12 is a sealing ring table, 13 is a push-pull rod, 14 is a compression sleeve, 15 is a first connecting hole, 16 is a second connecting hole, 17 is a third connecting hole, 18 is a locking ring table, 19 is a limiting ring table, 20 is a sealing element, 21 is a first valve head, 22 is a second valve head, and 23 is an elastic reset element. DETAILED DESCRIPTION

[0018] The application is not limited by the following embodiments, and the specific implementation manners can be determined according to the technical scheme of the application and the actual situation.

[0019] In the application, the relative position relationship of each component is described according to the layout mode of the drawings in the description, for example, the position relationship of front, back, top, bottom, left and right is determined according to the layout direction of the drawings in the description. Figure 1

[0020] The application will be further described below in combination with the embodiments and the drawings:

[0021] Embodiment one: as shown in the drawings, Figure 1 , 2 ​​As shown, the fixed gas lift working barrel for pressure operation includes a working barrel body 1, a casing pressure operation valve 2, a check valve head and a piston assembly. The upper and lower through-flow passages 3 and gas lift passages 4 are arranged at the upper end of the working barrel body 1. The casing pressure operation valve 2 is fixedly installed at the upper part of the gas lift passage 4 corresponding to the position above the through-flow hole 5. The check valve head is installed at the middle part of the gas lift passage 4 and is in sealing contact with the outlet of the casing pressure operation valve 2. The piston assembly is sealingly installed at the lower part of the gas lift passage 4. The upper end of the piston assembly is in abutment with the lower end of the check valve head. The check valve head can be connected with the through-flow hole 5 and the outlet of the casing pressure operation valve 2 after moving downward.

[0022] According to the requirement, the casing pressure operation valve 2 is a known technology. The upper part of the casing pressure operation valve 2 has an inlet. The right part of the gas lift passage 4 corresponding to the position above the check valve head has an upward opening notch. In this way, the liquid between the working barrel body 1 and the annulus of the wellbore can quickly enter the through-flow passage 3 through the inlet of the casing pressure operation valve 2. The casing pressure operation valve 2 is convenient to disassemble and assemble.

[0023] In use, the working barrel body 1 is lowered into the wellbore after being closed at the lower end by the piston assembly. At this time, the upper end of the check valve head is in sealing contact with the outlet of the casing pressure operation valve 2. The piston assembly is sealingly installed at the lower part of the gas lift passage 4. In this way, the through-flow hole 5 and the annulus are separated. When the normal gas lift operation is performed, the working barrel body 1 is pressurized. The high-pressure fluid acts on the piston assembly through the through-flow hole 5, so that the piston assembly moves downward. The high-pressure gas in the annulus acts on the upper end of the check valve head, so that the upper end of the check valve head moves downward to open the outlet of the casing pressure operation valve 2. In this way, the outlet of the casing pressure operation valve 2 and the through-flow hole 5 are connected, that is, the through-flow hole 5 and the annulus are connected. When the working barrel body 1 is lifted, the working barrel body 1 is continuously pressurized, so that the piston assembly continuously moves downward. At this time, the gas in the annulus acts on the lower end of the check valve head through the outlet of the casing pressure operation valve 2, so that the lower end of the check valve head moves to be in sealing contact with the gas lift passage 4 above the through-flow hole 5. In this way, the through-flow hole 5 and the annulus are separated, so that the working barrel body 1 is lifted. Through the above arrangement, the piston assembly can move downward by changing the pressure of the liquid in the annulus between the outside of the working barrel body and the inside of the wellbore. The through-flow hole and the annulus are connected and separated by the change of the position of the piston assembly. The difficulty of installing the rupture disc and the plug in each working barrel body 1 is reduced when the working barrel body 1 is operated under pressure. The operation is more simple and safe. The operation efficiency is improved. The production cost is reduced. The phenomenon of polluting the wellbore can be avoided.

[0024] According to the actual requirement, the fixed gas lift working barrel for pressure operation can be further optimized or / and improved.

[0025] Embodiment two: as the optimization of the above embodiment, as shown in the accompanying drawings Figure 1 , 2 The piston assembly includes a piston rod 6, a first shear pin 7, a second shear pin 8, a locking sleeve 9, and a support sleeve 10. An inner ring table 11 is fixed on the inner side of the gas lift passage 4 corresponding to the position above the overflow hole 5. The piston rod 6 is sealed and sleeved in the inner ring table 11. The upper end of the piston rod 6 abuts against the lower end of the valve head of the one-way valve, and the upper end of the one-way valve head closes the outlet of the pressure-operated valve 2. A sealing ring table 12 is fixed on the outer side of the lower end of the piston rod 6 corresponding to the position below the overflow hole 5, and is in sealing contact with the inner side of the gas lift passage 4. A push-pull rod 13 is fixed on the lower end of the sealing ring table 12. The first shear pin 7 is fixed and installed on the right inner side of the gas lift passage 4 corresponding to the position below the sealing ring table 12. The second shear pin 8 is fixed and installed on the inner side of the gas lift passage 4 corresponding to the position below the first shear pin 7. The support sleeve 10 is fixed and installed on the lower inner side of the gas lift passage 4 corresponding to the position below the second shear pin 8. The inner side of the support sleeve 10 is tapered from small to large. The locking sleeve 9 is installed between the inner side of the support sleeve 10 and the outer side of the push-pull rod 13. The outer side of the upper part of the locking sleeve 9 matches the inner side of the support sleeve 10, and the locking sleeve 9 can prevent the push-pull rod 13 from moving upward.

[0026] According to the requirements, the piston rod 6 is stepped from small to large. The first shear pin 7 is made of copper, which can prevent the upper part of the piston rod 6 from moving downward and separating from the inner ring table 11 due to external force during transportation or well drilling, so that the inner ring table 11 communicates with the overflow hole 5, causing plugging failure. The second shear pin 8 is made of steel, which can ensure that the sealing ring table 12 does not move downward during normal production. The inner side of the support sleeve 10 is tapered from small to large. The outer side of the locking sleeve 9 matches the inner side of the support sleeve 10. During use, the inner tapered surface of the support sleeve 10 and the outer tapered surface of the locking sleeve 9 cooperate with each other. When the push-pull rod 13 moves downward, it drives the locking sleeve 9 to move downward, so that the lower end of the locking sleeve 9 expands radially, allowing the push-pull rod 13 to move downward smoothly. When the push-pull rod 13 moves upward, the lower end of the locking sleeve 9 contracts under the action of the inner tapered surface of the support sleeve 10, which can prevent the push-pull rod 13 from continuing to move upward. The locking sleeve 9 reliably fixes the push-pull rod 13, and can position the sealing ring table 12.

[0027] In the pipe string into the well stage, the piston rod 6 is in the high position, the upper outer side of the piston rod 6 is in sealing contact with the inner ring table 11, and the upper outer side of the sealing ring table 12 is in sealing contact with the inner side of the gas lift channel 4, so that the flow hole 5 can be blocked. In the normal production stage, the piston rod 6 moves downward to the middle position, and there is a gap between the upper part of the piston rod 6 and the inner ring table 11, and the upper end of the piston rod 6 contacts the lower end of the check valve head to prevent the check valve head from moving downward, so that the inner side of the inner ring table 11 is in communication with the flow hole 5, and the gas in the working barrel body 1 and the annulus of the wellbore flows out of the sleeve pressure operating valve 2 outlet through the sleeve pressure operating valve 2 inlet, and the gas acts on the upper part of the check valve head to open the sleeve pressure operating valve 2 outlet, at this time the lower part of the check valve head is lifted by the upper part of the piston rod 6, and the gas flows into the flow channel 3 through the gap between the inner side of the inner ring table 11 and the piston rod 6 and the flow hole 5. In the pipe string pulling out stage, the sealing ring table 12 continues to move downward to the low position, and the upper end of the piston rod 6 moves downward to the inner side of the lower part of the inner ring table 11, at this time the lower part of the check valve head moves downward under the action of the gas in the working barrel body 1 and the annulus of the wellbore, and is in sealing contact with the inner side of the upper part of the inner ring table 11, realizing the blocking operation of the flow hole 5.

[0028] Start the production stage preparation, inject clean water into the flow channel 3, when the pressure reaches 7 to 9 MPa, the sealing ring table 12 cuts off the first shear pin 7 and moves downward, at the same time, the push-pull rod 13 moves downward to drive the locking sleeve 9 to move downward, the lower end of the locking sleeve 9 expands radially, the sealing ring table 12 moves quickly to the second shear pin 8 and stops, the piston rod 6 is in the middle position, the gas in the working barrel body 1 and the annulus of the wellbore flows out of the sleeve pressure operating valve 2 outlet through the sleeve pressure operating valve 2 inlet, and then flows into the flow channel 3 through the gap between the inner side of the inner ring table 11 and the piston rod 6 and the flow hole 5, that is, the gas lift operation production can be carried out.

[0029] When the pipe string is pulled out, the pressure is increased to 10 to 12 MPa, the sealing ring table 12 cuts off the second shear pin 8, and the second shear pin 8 falls into the screen pipe installed at the lower end of the working barrel body 1, and then the pressure is stopped. After the sealing ring table 12 cuts off the second shear pin 8, it continues to move downward, and the sealing ring table 12 is in the low position, and the upper end of the piston rod 6 is located inside the inner ring table 11, at this time the outer side of the working barrel body 1 and the gas in the annulus of the wellbore act on the lower end of the check valve head through the sleeve pressure operating valve 2 outlet, so that the lower part of the check valve head moves downward and is in sealing contact with the inner side of the inner ring table 11, at this time the flow hole 5 is closed and the pipe string can be pulled out smoothly.

[0030] When the push-pull rod 13 drives the locking sleeve 9 to move upward, the locking sleeve 9 moves upward by 4-6 mm, the outer side of the locking sleeve 9 contacts the inner side of the supporting sleeve 10, and the piston rod 6 is in the middle position. At this time, the lower end of the locking sleeve 9 is contracted under the action of the conical surface in the supporting sleeve 10, which prevents the push-pull rod 13 from continuing to move upward, so that the locking sleeve 9 reliably fixes the push-pull rod 13, and can position the sealing ring table 12.

[0031] Example three: as an optimization of the above-mentioned examples, as shown in the accompanying drawings Figure 1 、 2 The piston assembly further comprises a compression sleeve 14. The compression sleeve 14 is screwed to the inner side of the gas lift passage 4 corresponding to the lower end position of the supporting sleeve 10. The upper end of the compression sleeve 14 is provided with a first connecting hole 15, a second connecting hole 16 and a third connecting hole 17, which are sequentially connected from top to bottom. The inner diameter of the first connecting hole 15 is not less than the inner diameter of the lower end of the supporting sleeve 10. The inner diameter of the second connecting hole 16 is between the inner diameter of the first connecting hole 15 and the outer diameter of the push-pull rod 13. The projection of the third connecting hole 17 on the horizontal plane is located in the projection of the second connecting hole 16 on the horizontal plane. In use, the stepped surface of the first connecting hole 15 and the second connecting hole 16 can limit the locking sleeve 9 to prevent it from falling downward. The second connecting hole 16 can guide the push-pull rod 13 and prevent the locking sleeve 9 from falling.

[0032] Example four: as an optimization of the above-mentioned examples, as shown in the accompanying drawings Figure 1 、 2 The cross section of the third connecting hole 17 is a regular polygon. According to requirements, the cross section of the third connecting hole 17 is a regular hexagon. In use, the compression sleeve 14 is convenient to disassemble and assemble through such a setting.

[0033] Example five: as an optimization of the above-mentioned examples, as shown in the accompanying drawings Figure 1 、 2 The outer side of the push-pull rod 13 is provided with a plurality of tapered locking ring tables 18 with large upper and small lower, and the inner side of the locking sleeve 9 is provided with a plurality of tapered ring grooves with large upper and small lower matched with the locking ring tables 18.

[0034] According to the requirements, the locking sleeve 9 is made of spring steel, which is known to exist. During use, the locking ring platform 18 on the outside of the push-pull rod 13 cooperates with the conical ring groove. When the push-pull rod 13 moves downward, it can drive the locking sleeve 9 to move downward. When the lower end of the locking sleeve 9 moves to the stepped surface of the first connecting hole 15 and the second connecting hole 16, the push-pull rod 13 continues to move downward, which can cause the lower end of the locking sleeve 9 to open radially. After the push-pull rod 13 continues to move downward, it can contact the upper end of the second shear pin 8. When the pressure on the upper end of the sealing ring platform 12 increases, it can cut the second shear pin 8, which facilitates the switching of the position of the sealing ring platform 12. This drives the piston rod 6 to move downward, which causes the valve head of the single-flow valve to seal the inner ring platform 11, thereby disconnecting the flow hole 5 and the outlet of the sleeve pressure operating valve 2. With the setting of the conical ring groove, after the outer side of the locking sleeve 9 contacts the inner side of the support sleeve 10, the locking sleeve 9 radially contracts, which allows the locking ring platform 18 and the conical ring groove to cooperate and prevent the push-pull rod 13 from moving upward.

[0035] Example 6: As an optimization of the above examples, as shown in the appendix Figure 1 , 2 As shown, a limiting ring platform 19 is fixed to the outside of the piston rod 6 at the lower end of the inner ring platform 11, located above the sealing ring platform 12. During use, this arrangement ensures that when the sealing ring platform 12 moves upward, the upper end of the limiting ring platform 19 contacts the lower end of the inner ring platform 11. This prevents the upper end of the piston rod 6 from pressing against the check valve head and damaging it if the sealing ring platform 12 moves too far upward.

[0036] Example 7: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown, at least two seals 20 are evenly distributed vertically between the outer side of the piston rod 6 and the inner side of the inner ring platform 11, and between the upper outer side of the sealing ring platform 12 and the inner side of the air lift channel 4. Depending on the requirements, the seals 20 are existing known technologies, such as O-rings. The upper outer side of the piston rod 6 and the upper outer side of the sealing ring platform 12 are each provided with annular grooves that match the seals 20, and the seals 20 are installed within these grooves. During use, this arrangement reduces the machining accuracy and installation difficulty between the outer side of the piston rod 6 and the inner side of the inner ring platform 11, and between the upper outer side of the sealing ring platform 12 and the inner side of the air lift channel 4, thereby improving the sealing performance between the piston rod 6 and the inner side of the air lift channel 4, and ensuring the reliability of the piston rod 6's operation.

[0037] Example 8: As an optimization of the above examples, as shown in the appendix Figure 1 , 2As shown, the single-flow valve head comprises a first valve head 21, a second valve head 22 and an elastic reset member 23, the first valve head 21 and the second valve head 22 are symmetrically installed in the gas lift channel 4 above the position of the inner ring table 11, the elastic reset member 23 is installed between the lower part of the first valve head 21 and the lower part of the second valve head 22, the upper part of the first valve head 21 is in the shape of a spherical cap, the upper part of the first valve head 21 is in abutment with the inner side of the outlet of the sleeve pressure operating valve 2, and the lower end of the second valve head 22 is in abutment with the upper end of the piston rod 6.

[0038] According to the requirement, the elastic reset member 23 is a known technology, such as a compression spring, and the lower end of the second valve head 22 is located above the inner ring table 11. In use, the first valve head 21 is in abutment with the inner side of the outlet of the sleeve pressure operating valve 2 to close the sleeve pressure operating valve 2, and the lower end of the second valve head 22 is in abutment with the inner side of the inner ring table 11 to seal the inner ring table 11, thereby disconnecting the overflow hole 5 and the outlet of the sleeve pressure operating valve 2. By arranging the elastic reset member 23, the relative movement between the first valve head 21 and the second valve head 22 can be buffered, thereby reducing the failure rate.

[0039] The above technical features constitute embodiments of the present application, which have strong adaptability and implementation effect, and unnecessary technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A fixed air lift working cylinder for live operation, characterized in that... The device includes a working cylinder body, a pressure-operating valve, a one-way valve head, and a piston assembly. The upper end of the working cylinder body is provided with a flow passage and an air lift passage that are connected vertically at intervals on the left and right sides. The lower part of the working cylinder body is provided with a flow hole that connects the air lift passage and the flow passage. A pressure-operating valve is fixedly installed on the inner side of the upper part of the air lift passage corresponding to the position above the flow hole. A one-way valve head with its upper end sealed to the outlet of the pressure-operating valve is installed on the inner side of the middle part of the air lift passage. The inner side of the lower part of the air lift passage and the outer side of the piston assembly are sealed together. The upper end of the piston assembly abuts against the lower end of the one-way valve head, and the upper end of the one-way valve head can connect the flow hole and the outlet of the pressure-operating valve after it moves downward. The piston assembly includes a piston rod, a first shear pin, a second shear pin, a locking sleeve, and a support sleeve. An inner ring platform is fixed to the inner side of the air lift channel above the flow orifice. The piston rod is sealed within the inner ring platform. The upper end of the piston rod abuts against the lower end of the one-way valve head, causing the upper end of the one-way valve head to close the outlet of the pressure operating valve. A sealing ring platform is fixed to the outer side of the lower end of the piston rod below the flow orifice, sealingly contacting the inner side of the air lift channel. A push-pull rod is fixed to the center of the lower end of the sealing ring platform. A first shear pin is fixed to the inner right side of the air lift channel below the sealing ring platform. A second shear pin is fixed to the inner side of the air lift channel below the first shear pin. A support sleeve is fixed to the inner lower part of the air lift channel below the second shear pin. The inner side of the support sleeve is tapered, wider at the bottom than the top. A locking sleeve is installed between the inner side of the support sleeve and the outer side of the push-pull rod. The upper outer side of the locking sleeve matches the inner side of the support sleeve, and the locking sleeve prevents the push-pull rod from moving upwards. The single-flow valve head includes a first valve head, a second valve head, and an elastic reset element. The first valve head and the second valve head are symmetrically installed in the air lift channel above the inner ring platform. An elastic reset element is installed between the lower part of the first valve head and the lower part of the second valve head. The outer side of the upper part of the first valve head is spherical and abuts against the inner side of the outlet of the sleeve pressure operating valve. The lower end of the second valve head abuts against the upper end of the piston rod. In the initial production preparation stage, clean water is injected into the flow channel. When the pressure reaches a certain value, the sealing ring platform cuts the first shear pin and moves downward. At the same time, the push-pull rod moves downward, which in turn drives the locking sleeve to move downward. After the lower end of the locking sleeve opens radially, the sealing ring platform quickly moves to the second shear pin and stops. When the tubing string is pulled out, the pressure is increased. After the sealing ring platform cuts the second shear pin, it moves downward. The sealing ring platform is in a low position, and the upper end of the piston rod is located inside the inner ring platform. At this time, the gas outside the working barrel body and the gas in the wellbore annulus act on the lower end of the one-way valve head through the outlet of the casing pressure operating valve, so that the lower part of the one-way valve head moves downward and makes sealing contact with the inner side of the inner ring platform.

2. The fixed air lift working cylinder for live operation according to claim 1, characterized in that... The piston assembly also includes a clamping sleeve, which is screwed into the inner side of the air lift channel at the lower end of the support sleeve. The upper inner side of the clamping sleeve is provided with a first connecting hole, a second connecting hole and a third connecting hole that are connected sequentially from top to bottom. The inner diameter of the first connecting hole is not less than the inner diameter of the lower end of the support sleeve. The inner diameter of the second connecting hole is between the inner diameter of the first connecting hole and the outer diameter of the push-pull rod. The projection of the third connecting hole on the horizontal plane is located at the projection of the second connecting hole on the horizontal plane.

3. The fixed air lift working cylinder for live operation according to claim 2, characterized in that... The cross-section of the third connecting hole is a regular polygon.

4. The fixed air lift working cylinder for live operation according to claim 1, 2, or 3, characterized in that... The outer side of the push-pull rod is provided with several tapered locking ring platforms that are larger at the top and smaller at the bottom, and the inner side of the locking sleeve is provided with several tapered ring grooves that match the locking ring platforms, which are larger at the top and smaller at the bottom.

5. The fixed air-lift working cylinder for live operation according to claim 1, 2, or 3, characterized in that... A limiting ring platform is fixed on the outside of the piston rod at the lower end of the inner ring platform, located above the sealing ring platform.

6. The fixed air-lift working cylinder for live operation according to claim 4, characterized in that... A limiting ring platform is fixed on the outside of the piston rod at the lower end of the inner ring platform, located above the sealing ring platform.

7. The fixed air-lift working cylinder for live operation according to claim 1, 2, 3, or 6, characterized in that... At least two seals are evenly distributed vertically between the outer side of the piston rod and the inner side of the inner ring platform, the upper outer side of the sealing ring platform, and the inner side of the air lift channel.

8. The fixed air lift working cylinder for live operation according to claim 4, characterized in that... At least two seals are evenly distributed vertically between the outer side of the piston rod and the inner side of the inner ring platform, the upper outer side of the sealing ring platform, and the inner side of the air lift channel.

9. The fixed air-lift working cylinder for live operation according to claim 5, characterized in that... At least two seals are evenly distributed vertically between the outer side of the piston rod and the inner side of the inner ring platform, the upper outer side of the sealing ring platform, and the inner side of the air lift channel.

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