Under-pressure tubular column tripping operation device and working method thereof

Abstract

The invention relates to the field of petroleum machinery, in particular to an under-pressure tubular column lifting operation device and a working method thereof.The operation device comprises a plurality of lifting oil cylinders, the lifting oil cylinders are installed in stand columns, and the upper ends and the lower ends of the stand columns are fixedly connected through an upper cross beam and a lower cross beam correspondingly; a lifting piston of the lifting oil cylinder supports the movable cross beam, a rotating device is installed in the center of the movable cross beam, a movable bearing slip is installed above the rotating device, and a movable anti-jacking slip is installed below the rotating device. The lower cross beam is sequentially provided with an annular blowout preventer, a fixed slip set, a safety slip set and a three-flashboard integrated blowout preventer from top to bottom. Three oil ports are adopted for cooperative control, a Z-shaped annular spraying piston, an arc-shaped rubber core and a built-in iron core framework structure are combined, a hydraulic system redundancy pressure stabilization mechanism, a safety protection mechanism and structural optimization are combined, the high-pressure working condition requirement in under-pressure operation is met, and dynamic sealing adjustment is achieved.

Description

Technical Field

[0001] This invention relates to the field of petroleum machinery, specifically to a live tubing lifting and lowering device, and also to a method for operating the live tubing lifting and lowering device. Background Technology

[0002] In oil and gas field maintenance operations, traditional well control techniques face significant technical bottlenecks. When dealing with pressurized oil and water wells, conventional operations require the injection of high-density kill fluid to increase the wellbore fluid column pressure, thereby suppressing formation pressure to achieve a zero-pressure state at the wellhead and ensuring the safety of open-hole operations. However, this process presents a triple contradiction: firstly, it requires a large investment of human and material resources; secondly, well control fluid penetration can easily cause formation pore blockage, leading to reservoir contamination and ultimately resulting in the dual risks of reduced production capacity and economic losses.

[0003] To address this industry pain point, the industry has developed an innovative live-line operation equipment system. Compared with traditional tubing operations, this device allows for direct operation while the well is under pressure, avoiding time losses and safety risks associated with depressurization and production stoppages, resulting in significant economic benefits and safety advantages. It is particularly suitable for complex operating environments such as high-pressure wells, accompanying gas wells, gas lift wells, and injection wells where depressurization is difficult or frequent production stoppages are not advisable. The core of this device lies in achieving "live-line" operation, that is, completing the tubing string tripping operation while the wellhead pressure is still present. This places high demands on the equipment's sealing performance, safety, and operational precision. Therefore, the device is typically equipped with a high-performance blowout preventer (BOP), a multi-stage sealing structure, a blowback prevention system, a hydraulic control unit, and a high-strength mechanical structure. The BOP is positioned above the wellhead, its main function being to provide a reliable seal during tubing string passage, preventing downhole oil and gas from escaping from the wellhead, while also possessing a certain pressure resistance. Some devices also have shearing and shut-off functions, allowing for rapid cutting of the tubing string and sealing of the wellhead in emergencies, ensuring the safety of personnel and equipment.

[0004] The existing pressurized tubing string lowering and lowering equipment still has the following problems that urgently need to be improved: 1. Annular blowout preventers (BOPs) can form an effective seal in a short time, effectively preventing high-pressure fluid from being ejected from the well and ensuring the safety of drilling operations. However, existing annular BOPs mainly use pressurized oil entering the lower oil chamber (closing the oil chamber) to push the annular blowout piston upwards rapidly. The rubber core is restricted by the top cap and cannot move upwards. Under the action of the inner conical surface of the annular blowout piston, it is forced to squeeze and compress towards the center of the wellbore, encircling the drill string. The rubber core deforms significantly during the sealing process, which places high demands on the performance of the rubber core. After long-term use, it is prone to fatigue damage, leading to seal failure. 2. When obstacles or blockages hinder the lowering of the drill string in the formation, the drill pipe needs to be ground and cleared. Existing live drilling rigs use a clamping slip structure, requiring a hydraulic lock to secure the drill pipe. The hydraulic lock and slips are rotary, with external hydraulic circuitry controlling the clamping and releasing of the drill pipe. When the slips need to clamp or release the drill pipe, the turntable must be stationary, and the hydraulic lock mechanism, connected to the rotary structure, must be inserted to actuate the slips. This process involves frequent insertion and removal of the external hydraulic circuitry, which can lead to insufficient clamping force and drill pipe loosening if leaks occur at the interface. Furthermore, it results in long downtimes and disrupts continuous operation. 3. The existing hydraulic circuit of the pressurized lifting and lowering column operation device is mainly integrated and managed by the hydraulic station, but the hydraulic circuit safety measures are insufficient, and the operation safety accident is prone to occur due to the defects of the oil circuit; at the same time, the handle needs to be operated frequently during operation, which is prone to misoperation. Summary of the Invention

[0005] This section aims to outline certain aspects of embodiments of the present invention and briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, but such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] The primary objective of this invention is to overcome the problems existing in the prior art and provide a wellhead blowout preventer for live operations. This device can achieve live tubing string setup, meet the operational requirements under high-pressure well conditions, and ensure wellhead safety.

[0007] To solve the above technical problems, the present invention provides a pressurized lifting and lowering pipe column operation device, comprising multiple lifting cylinders 1, wherein the lifting cylinders 1 are installed inside the column 2, and the upper and lower ends of the column 2 are fixedly connected by an upper crossbeam 3 and a lower crossbeam 4, respectively. The lifting piston of the lifting cylinder 1 supports the movable crossbeam 13, and a rotating device 7 is installed at the center of the movable crossbeam 13. A movable load-bearing slip 5 is installed above the rotating device 7, and a movable anti-overhead slip 6 is installed below the rotating device 7. The lower crossbeam 4 is sequentially equipped with an annular blowout preventer 8, a fixed slip group 9, a safety slip group 10, and a three-gate integrated blowout preventer 12 from top to bottom.

[0008] Furthermore, the side of the safety slip assembly 10 is connected to a balance pressure relief valve assembly 11, which includes a balance valve and a pressure relief valve. The three-gate integrated blowout preventer 12 includes a lower semi-sealed gate blowout preventer 1201, a safety semi-sealed gate blowout preventer 1202, and a fully sealed gate blowout preventer 1203.

[0009] Furthermore, the annular blowout preventer 8 includes a lower housing 801, a middle housing 810, a top cover 802, a rubber core 803, a dustproof ring 804, and an annular blowout piston 805. The annular blowout piston 805 has a Z-shaped cross-section. The rubber core 803 is a cylindrical shape that is thicker at both ends and thinner in the middle. Its outer and inner surfaces are both arc-shaped curved surfaces with concave edges. The upper and lower ends of the rubber core 803 are connected to metal fixing plates 806. The upper and lower metal fixing plates 806 of the rubber core 803 abut against the annular blowout piston 805 and the top cover 802, respectively. There is a cavity between the outer surface of the rubber core 803 and the middle housing 810.

[0010] Furthermore, the bottom of the lower housing 801 is provided with a first oil port 807 that communicates with the bottom of the ring injection piston 805, and the upper side wall of the lower housing 801 is provided with a second oil port 808 that communicates with the upper part of the ring injection piston 805.

[0011] Furthermore, a third oil port 811 is provided in the middle of the middle housing 810, which communicates with the outer peripheral cavity of the rubber core 803.

[0012] Furthermore, during normal use, oil enters through the first oil port and exits through the second oil port, causing the ring-jet piston 805 to press the rubber core 803 upward; if the sealing is not achieved within the set time, hydraulic oil is injected through the third oil port.

[0013] Furthermore, an iron core is provided inside the rubber core 803. The iron core includes several sets of skeletons evenly distributed along the circumference of the rubber core 803. Each set of skeletons includes two hinged metal supports 809.

[0014] Furthermore, the two metal supports 809 are of the same length, and the ends of the metal supports 809 abut against the upper and lower metal fixing plates 806 respectively.

[0015] Furthermore, the cross-section of the metal fixing plate 806 is Z-shaped, and an arc groove is provided at the Z-shaped corner. The end of the metal support 809 has an arc-shaped profile, and the end of the metal support 809 abuts against the arc groove of the metal fixing plate 806.

[0016] Furthermore, the thickness of the middle part of the adhesive core 803 is greater than the thickness of the upper and lower ends of the adhesive core 803.

[0017] Furthermore, two seals are respectively provided between the metal fixing plate 806, the ring-jet piston 805, and the top cover 802.

[0018] Furthermore, a hydraulic station 14 is also provided, which is equipped with a gear pump 1401 and a plunger pump 1402. There are two gear pumps 1401 connected in parallel, one for high flow and relatively low pressure oil supply, and the other for low flow and relatively high pressure oil supply. The inlets of both gear pumps are connected to an oil tank, and the outlets are respectively connected to the pressure oil circuit P1. The outlet pipe of the plunger pump 1402 is connected to multiple accumulators 1403 and connected to the pressure oil circuits P2 and P3 through a pressure reducing valve group.

[0019] Furthermore, pressure oil circuit P1 is connected to port P of lifting directional valve Y1, port T of lifting directional valve Y1 is connected to the oil tank, port A of lifting directional valve Y1 is connected to the lower chamber of each lifting cylinder 1, and port B of lifting directional valve Y1 is connected to the upper chamber (rod chamber) of each lifting cylinder 1. Lifting directional valve Y1 is a three-position four-way directional valve with a neutral position function of type O. Pressure oil circuit P2 is connected to port P of lifting control valve Y2, port T of lifting control valve Y2 is connected to the oil tank. Lifting control valve Y2 is a three-position four-way directional valve with a neutral position function of type O. Port A of lifting control valve Y2 is connected to the left hydraulic control port of lifting directional valve Y1, and port B of lifting control valve Y2 is connected to the right hydraulic control port of lifting directional valve Y1.

[0020] Furthermore, a lifting cylinder balance valve H1 is installed between port B of the lifting directional valve Y1 and the rod chamber of each lifting cylinder 1. The hydraulic control port of the lifting cylinder balance valve H1 is connected to port A of the lifting directional valve Y1. When oil is introduced into the lower chamber of each lifting cylinder 1 and it is lifted upward, port P of the lifting control valve Y2 is connected to port A, and port B is connected to port T, causing the lifting directional valve Y1 to switch to the left position, so that port P of the lifting directional valve Y1 is connected to port A, and port B is connected to port T, and the lifting cylinder balance valve H1 is in a throttling and connected state. In the first position, the oil in the rod chamber of each lifting cylinder 1 is throttled by the lifting cylinder balance valve H1 and then returns to the oil tank through the B and T ports of the lifting directional valve Y1. When the rod chamber of each lifting cylinder 1 descends, the P port of the lifting control valve Y2 is connected to the B port, and the A port is connected to the T port, causing the lifting directional valve Y1 to switch to the right position, so that the P port of the lifting directional valve Y1 is connected to the B port, and the A port is connected to the T port. The lifting cylinder balance valve H1 is in an upward unidirectional and damped state, and the lower chamber of each lifting cylinder 1 returns oil directly to the oil tank.

[0021] Furthermore, the pressure oil circuit P3 is connected to the P port of the first annular injection directional valve Y7. The first annular injection directional valve Y7 is a three-position four-way directional valve with a neutral position function of type O. The T port of the first annular injection directional valve Y7 is connected to the oil tank. The A port of the first annular injection directional valve Y7 is connected to the first oil port 807 of the annular release valve 8 through the left path of the annular injection hydraulic lock ZD1. The B port of the first annular injection directional valve Y7 is connected to the second oil port 808 of the annular release valve 8 through the right path of the annular injection hydraulic lock ZD1.

[0022] Furthermore, the A port of the first annular injection directional valve Y7 is also connected to the P port of the second annular injection directional valve Y8, the T port of the second annular injection directional valve Y8 is connected to the oil tank, the second annular injection directional valve Y8 is a two-position three-way directional valve, and the A port of the second annular injection directional valve Y8 is connected to the third oil port 811 of the annular blower 8.

[0023] Furthermore, when the annular blower 8 needs to be sealed, firstly, the P port of the first annular blower reversing valve Y7 is connected to the A port, and the B port is connected to the T port. Oil enters through the first oil port 807 and exits through the second oil port 808. The annular blower piston 805 moves upward, and the rubber core 803 is squeezed to seal the outer circumference of the tubing. If the seal is not tight, the P port of the second annular blower reversing valve Y8 is connected to the A port, the third oil port 811 builds pressure, and the rubber core 803 further contracts inward to seal the outer circumference of the tubing.

[0024] Furthermore, when the annular blower 8 needs to be opened, firstly, the A port of the second annular blower reversing valve Y8 is connected to the T port, and the third oil port 811 first releases pressure; then, the P port of the first annular blower reversing valve Y7 is connected to the B port, and the A port is connected to the T port, the second oil port 808 receives oil, the first oil port 807 receives oil, the annular blower piston 805 descends, and the rubber core 803 returns to its original state.

[0025] Furthermore, the rotary device 7 includes an intermediate connecting seat 711, a rotary gear 705, and a lower bushing 706. The rotary gear 705 and the lower bushing 706 are mounted in the intermediate connecting seat 711 via bearings. The rotary gear 705 and the lower bushing 706 are fixedly connected and can rotate relative to the intermediate connecting seat 711. The movable load-bearing slip 5 and the movable anti-top slip 6 adopt a conical clamping structure. The intermediate connecting seat 711 is fixed to the movable crossbeam 13. The intermediate connecting seat 711 has a release oil inlet 701 and a release oil return port 704 on both sides. 1. The oil inlet pipe 702 is axially arranged inside the intermediate connecting seat 711. The oil inlet pipe 702 is connected to the upper first oil hole and the lower second oil hole on the inner side of the intermediate connecting seat 711. The chuck release oil return port 704 is connected to the oil return pipe 703 axially arranged inside the intermediate connecting seat 711. The oil return pipe 703 and the oil inlet pipe 702 are symmetrical about the center of the intermediate connecting seat 711. The oil return pipe 703 is connected to the upper third oil hole and the lower fourth oil hole on the inner side of the intermediate connecting seat 711. The cylindrical surface of the lower part of the rotary gear 705 is provided with a first groove and a second groove. The groove is connected to the first oil hole of the intermediate connecting seat 711, and the second groove is connected to the third oil hole of the intermediate connecting seat 711; an L-shaped upper oil inlet branch pipe 709 is provided inside one side of the rotary gear 705, and the upper oil inlet branch pipe 709 is connected to the first groove; an L-shaped upper oil return branch pipe 710 is provided inside the other side of the rotary gear 705, and the upper oil return branch pipe 710 is connected to the second groove; the rotary gear 705 is connected to the movable load-bearing slip 5, and the upper oil inlet branch pipe 709 and the upper oil return branch pipe 710 are connected to the slip seat of the movable load-bearing slip 5; on the cylindrical surface of the lower bushing 706 The lower bushing 706 has a third groove and a fourth groove. The third groove is connected to the second oil hole of the intermediate connecting seat 711, and the fourth groove is connected to the fourth oil hole of the intermediate connecting seat 711. An L-shaped lower oil inlet branch pipe 707 is provided inside one side of the lower bushing 706, and the lower oil inlet branch pipe 707 is connected to the third groove. An L-shaped lower oil return branch pipe 708 is provided inside the other side of the lower bushing 706, and the lower oil return branch pipe 708 is connected to the fourth groove. The lower bushing 706 is connected to the movable anti-top slip 6, and the lower oil inlet branch pipe 707 and the lower oil return branch pipe 708 are connected to the slip seat of the movable anti-top slip 6.

[0026] Furthermore, the inner hole of the intermediate connecting seat 711 is provided with a fifth groove, a sixth groove, a seventh groove, an eighth groove, a ninth groove, and a tenth groove, which are filled with sealing rings to prevent leakage of hydraulic oil used for clamping control. After the central connecting seat is installed and fitted with the rotary gear 705 and the lower bushing 706, the fifth groove is located above the second groove, the sixth groove is located between the second groove and the first groove, and the seventh groove is located below the first groove; the eighth groove is located above the third groove, the ninth groove is located between the third groove and the fourth groove, and the ninth groove is located below the fourth groove.

[0027] Furthermore, the pressure oil circuit P2 is connected to the P port of the movable slip directional valve Y3. The movable slip directional valve Y3 is a three-position four-way solenoid directional valve with a neutral position function of type O. The T port of the movable slip directional valve Y3 is connected to the oil tank. The A port of the movable slip directional valve Y3 is connected to the rodless chamber of the cylinder of the movable load-bearing slip 5 and the movable anti-jacking slip 6 through the left path of the movable slip hydraulic lock ZD2 and the second hydraulic control check valve Q2. The B port of the movable slip directional valve Y3 is connected to the rod chamber of the cylinder of the movable load-bearing slip 5 and the movable anti-jacking slip 6 through the right path of the movable slip hydraulic lock ZD2. The pressure oil circuit P2 is connected to the P port of the fixed slip directional valve Y4. The fixed slip directional valve Y4 is a three-position four-way solenoid directional valve with a neutral position function of type O. The T port of the fixed slip directional valve Y4 is connected to the oil tank. The A port of the fixed slip directional valve Y4 is connected to the rodless chamber of the cylinder of the fixed slip assembly 9 through the left path of the fixed slip hydraulic lock ZD3. The B port of the fixed slip directional valve Y4 is connected to the rod chamber of the cylinder of the fixed slip assembly 9 through the right path of the fixed slip hydraulic lock ZD3 and the first hydraulic control check valve Q1. The hydraulic control port of the first hydraulic control check valve Q1 is connected to the rodless chamber oil circuit of the movable load-bearing slip 5 and the movable anti-top slip 6. The hydraulic control port of the second hydraulic control check valve Q2 is connected to the rodless chamber oil circuit of the cylinder of the fixed slip assembly 9.

[0028] Furthermore, when the rodless chamber of the cylinder of the fixed slip assembly 9 is pressurized, the second hydraulic check valve Q2 can be opened upwards, allowing pressurized oil to enter the cylinder rod chamber of the movable load-bearing slip 5 and the movable anti-jacking slip 6; only when the fixed slip assembly 9 is tightened can the movable load-bearing slip 5 and the movable anti-jacking slip 6 be released; only when the rodless chamber of the cylinder of the movable load-bearing slip 5 and the movable anti-jacking slip 6 is pressurized, can the first hydraulic check valve Q1 be opened upwards, allowing pressurized oil to enter the cylinder rod chamber of the fixed slip assembly 9; only when the movable load-bearing slip 5 and the movable anti-jacking slip 6 are tightened can the fixed slip assembly 9 be released.

[0029] Another objective of this invention is to overcome the problems existing in the prior art and provide a working method for a wellhead blowout preventer for live operations, which can realize live tubing string raising, meet the operational requirements under high-pressure well conditions, and ensure wellhead safety.

[0030] To solve the above technical problems, the working method of the pressurized lowering pipe string operation device of the present invention includes the following steps: S1. Close the movable load-bearing clamp 5, close the movable anti-top clamp 6, and clamp the upper part of the pipe column; S2. Close the annular blowout preventer 8, open the balance valve in the balance relief valve group 11 to introduce downhole pressure, so that the pressure in the upper and lower chambers of the lower half-sealed gate blowout preventer 1201 is equal; open the lower half-sealed gate blowout preventer 1201, open the fixed slip group 9, and loosen the lower part of the tubing string. S3, the lifting cylinder 1 moves upward, and the tubing passes through the rubber core 803 of the annular blowout preventer 8 and is lifted; S4. Close the lower half-sealed gate blowout preventer 1201 and close the balance valve in the balance relief valve group 11; S5. Close the fixed slip group 9 and clamp the already lifted pipe column; open the movable load-bearing slip 5 and the movable anti-overhead slip 6, and release the pipe column using the movable load-bearing slip 5 and the movable anti-overhead slip 6. S6. Lifting cylinder 1 descends to its minimum stroke to continue lifting the tubing column.

[0031] Furthermore, it also includes the following steps: S7. Repeat S1-S6 cycle until the connection of the two tubing columns rises below the rubber core 803 of the annular blowout preventer 8. To avoid damage to the rubber core of the annular blowout preventer 8 by the tubing column connection with a larger diameter, close the lower half-sealing gate blowout preventer 1201, open the pressure relief valve of the balance pressure relief valve group 11 to release the oil pressure, then open the annular blowout preventer 8, lift the hydraulic cylinder 1 upward, and the connection of the tubing column passes through the annular blowout preventer 8. S8. Close the annular blowout preventer 8, close the pressure relief valve of the balance pressure relief valve group 11, open the balance valve in the balance pressure relief valve group 11, introduce downhole pressure, so that the pressure in the upper and lower chambers of the lower half-sealed gate blowout preventer 1201 is equal; then open the lower half-sealed gate blowout preventer 1201 to avoid pressure shock to the lower half-sealed gate blowout preventer 1201. S9. Close the fixing slip group 9 to clamp the next section of the tubing; S10. Open the movable load-bearing slip 5 and the movable anti-top slip 6. Rotate the pipe column using hydraulic power clamps and place the dislodged pipe column into the pipe column conveyor using a hook for pipe column recovery. S11. Lifting cylinder 1 descends to its minimum stroke, closes the moving load-bearing slip 5, closes the moving anti-overhead slip 6, clamps the upper part of the next section of the pipe column, and begins lifting and lowering the next section of the pipe column. Repeat the above steps.

[0032] Compared with existing technologies, this invention achieves the following beneficial effects: 1. This invention solves problems such as sealing failure, pressure fluctuation, and tubing runaway in traditional pressurized operations through dynamic sealing of the annular blowout preventer, redundant pressure stabilization of the hydraulic system, safety protection mechanisms, and structural optimization. Its modular design, collaborative control logic, and high adaptability significantly improve the safety and efficiency of well workover and oil testing operations in oil and gas fields, reduce blowout risks and maintenance costs, and have significant engineering application value; 2. This invention employs a three-port coordinated control system, combined with a Z-shaped ring-jet piston, an arc-shaped rubber core, and a built-in iron core skeleton structure, to achieve dynamic sealing adjustment. The rubber core contracts through hydraulic oil injection into the cavity, adapting to tools of different diameters and ensuring a stable sealing effect. The metal support skeleton enhances the compressive strength of the rubber core, preventing uneven deformation and extending its service life. 3. This invention employs a conical clamping structure for the movable load-bearing slips and movable anti-overhead slips, instead of the traditional clamping structure, which can lock the drill string. For applications requiring drill string rotation, a rotation device is provided. A hydraulic motor drives a rotary gear, which in turn rotates the movable load-bearing slips and movable anti-overhead slips, thereby rotating the drill pipe. When replacing or disassembling the drill pipe, there is no need for an external hydraulic circuit to drive the hydraulic locking mechanism as in traditional methods. Dynamic sealing can be achieved through the release oil inlet and release oil return port on the intermediate connecting seat, allowing for release without stopping the machine. 4. The hydraulic circuit of this invention is rationally designed and features safety redundancy. Hydraulic lock structures are installed on the inlet and return oil lines of the balance valve, pressure relief valve, annular blowout preventer, gate blowout preventer, fixed slip, and movable slip to achieve bidirectional locking of the hydraulic cylinder. A lifting cylinder balance valve is installed on the lifting cylinder to stabilize its speed and prevent excessive load from causing hydraulic cylinder runaway. In the control circuits of the third port and the first and second ports of the annular blowout preventer, a dual-pressure valve is installed after the second and first annular blowout reversing valves. The outlet of the dual-pressure valve is connected to the third port, ensuring that the backup third port only performs oil inlet sealing when the bottom annular blowout piston is lifted and if it is not sealed within a set time. An interlocking structure is installed between the oil lines of the movable load-bearing slip and the movable anti-top slip and the oil line of the fixed slip, ensuring that at least one of the fixed slip and the movable slip clamps the tubing, thus enhancing safety. 5. When using traditional methods to raise and lower tubing strings, a tubing string lifting clamp is required. Since the clamp is suspended by a wire rope, its lifting trajectory is unstable and prone to swaying, often damaging the tubing string. The pressurized tubing string raising and lowering device provided by this invention uses multiple lifting operations to raise and lower the entire tubing string. The hydraulic cylinder does not require a large stroke, resulting in a smaller height and footprint during transportation. Simultaneously, during lifting at the tubing string connection, the rubber core of the annular blowout preventer is opened for protection. This opening is achieved through a balanced pressure relief valve assembly, preventing pressure shocks from downhole high pressure to the lower half-sealed gate blowout preventer. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are for reference and illustration only and should not be used to limit the present invention. Wherein: Figure 1 This is a three-dimensional view of the pressure-lifting and lowering pipe column operation device of the present invention; Figure 2 This is a front sectional view of the pressurized lowering pipe column operation device of the present invention; Figure 3 for Figure 2A partially enlarged view of Embodiment 1 of the medium-ring blowout preventer; Figure 4 for Figure 2 A partially enlarged view of Embodiment 2 of the medium-ring blowout preventer; Figure 5 This is a schematic diagram of the hydraulic station; Figure 6 This is a schematic diagram of the hydraulic circuit for a gear pump. Figure 7 This is a schematic diagram of the hydraulic circuit of a plunger pump. Figure 8 This is a schematic diagram of the hydraulic piping connection for a ring-shaped blowout preventer. Figure 9 This is a schematic diagram of the pressure oil circuit P1. Figure 10 This is a schematic diagram of the pressure oil circuit P2. Figure 11 This is a schematic diagram of the pressure oil circuit P3. Figure 12 The front view of the connection between the movable load-bearing slip, the movable anti-top slip, and the rotating device; Figure 13 for Figure 12 A sectional view; Figure 14 for Figure 12 A three-dimensional image; Figure 15 A sectional view of the rotary device mounted on the moving crossbeam; In the diagram: 1. Lifting cylinder; 2. Column; 3. Upper crossbeam; 4. Lower crossbeam; 5. Movable load-bearing slip; 6. Movable anti-tipping slip; 7. Rotary device; 701. Clamp release oil inlet; 702. Main oil inlet pipe; 703. Main oil return pipe; 704. Clamp release oil return port; 705. Rotary gear; 706. Lower bushing; 707. Lower oil inlet branch pipe; 708. Lower oil return branch pipe; 709. Upper oil inlet branch pipe; 710. Upper oil return branch pipe; 711. Intermediate connecting seat; 8. Annular Blowout Preventer; 801. Lower Housing; 802. Top Cover; 803. Rubber Core; 804. Dust Ring; 805. Annular Blowout Piston; 806. Metal Fixing Plate; 807. First Oil Port; 808. Second Oil Port; 809. Metal Support; 810. Middle Housing; 811. Third Oil Port; 9. Fixed slip assembly; 10. Safety slip assembly; 11. Balanced pressure relief valve assembly; 12. Three-gate integrated blowout preventer; 1201. Lower semi-sealed gate blowout preventer; 1202. Safety semi-sealed gate blowout preventer; 1203. Fully sealed gate blowout preventer; 13. Move the crossbeam; 14. Hydraulic power unit; 1401. Gear pump; 1402. Piston pump; 1403. Accumulator; 15. Hydraulic motor; Y1, Lifting directional valve; Y2, Lifting control valve; Y3, Moving slip directional valve; Y4, Fixed slip directional valve; Y5, Balance directional valve; Y6, Pressure relief directional valve; Y7, First ring spray directional valve; Y8, Second ring spray directional valve; Y9, Lower half-sealing directional valve; Y10, Safety half-sealing directional valve; Y11, Full-sealing directional valve; H1, Lifting cylinder balance valve; ZD1, Ring spray hydraulic lock; ZD2, Moving slip hydraulic lock; ZD3, Fixed slip hydraulic lock; ZD4, Balance valve hydraulic lock; ZD5, Pressure relief valve hydraulic lock; ZD6, Lower semi-sealed hydraulic lock; ZD7, Safety semi-sealed hydraulic lock; ZD8, Fully sealed hydraulic lock; Q1, First hydraulic control check valve; Q2, Second hydraulic control check valve. Detailed Implementation

[0034] In the following description of the present invention, the terms "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not mean that the device must have a specific orientation.

[0035] To make the technical means, inventive features, achieved objectives, and effects of this invention easier to understand, the invention is further described below with reference to specific illustrations. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0036] like Figure 1 , Figure 2As shown, the wellhead blowout preventer for pressurized operations of the present invention includes four lifting cylinders 1, each of which is installed inside a column 2. The upper and lower ends of the column 2 are fixedly connected by an upper crossbeam 3 and a lower crossbeam 4, respectively. The lifting piston of the lifting cylinder 1 supports a movable crossbeam 13. A rotating device 7 is installed at the center of the movable crossbeam 13. A movable load-bearing slip 5 is installed above the rotating device 7, and a movable anti-overhead slip 6 is installed below the rotating device 7. The lower crossbeam 4 is installed from top to bottom with an annular blowout preventer 8, a fixed slip assembly 9, a safety slip assembly 10, and a three-gate integrated blowout preventer 12. A balance pressure relief valve assembly 11 is connected to the side of the safety slip assembly 10. The balance pressure relief valve assembly 11 includes a balance valve and a pressure relief valve. The three-gate integrated blowout preventer 12 includes a lower semi-sealed gate blowout preventer 1201, a safety semi-sealed gate blowout preventer 1202, and a fully sealed gate blowout preventer 1203.

[0037] like Figure 3 As shown, the annular blowout preventer 8 includes a lower housing 801, a middle housing 810, a top cover 802, a rubber core 803, a dust seal 804, and an annular blowout piston 805. The lower housing 801 and the middle housing 810 are connected by bolts, and the top cover 802 is installed on the upper port of the middle housing 810. The annular blowout piston 805 has a Z-shaped cross-section, and the rubber core 803 is a cylindrical shape that is thicker at both ends and thinner in the middle. Its outer and inner surfaces are both arc-shaped curved surfaces, and the arc edges are concave inward. Metal fixing plates 806 are connected to the upper and lower ends of the rubber core 803. The upper and lower metal fixing plates 806 of the rubber core 803 abut against the ring injection piston 805 and the top cover 802 respectively. There is a cavity between the outer side of the rubber core 803 and the middle housing 810. The lower housing 801 is provided with a first oil port 807 and a second oil port 808. The side wall of the middle housing 810 is provided with a third oil port 811. The first oil port 807 is connected to the bottom of the ring injection piston 805, the second oil port is connected to the upper part of the ring injection piston 805, and the third oil port 811 is connected to the cavity of the middle housing 810.

[0038] During live operation, hydraulic oil is injected into the first port 807 of the annular blowout preventer 8, and oil exits from the second port 808, pushing the annular blowout piston 805 upward and compressing the rubber core 803. The rubber core 803 contracts inward and seals against the outer circumference of the tubing string. The rubber core 803 is made of natural rubber and can also seal other shaped tools, including square drill rods, drill rods, drill rod joints, drill collars, casings, cables, etc. When dealing with tools of different diameters or in emergency situations, hydraulic oil can be injected appropriately into the first port 807 to raise the height of the annular blowout piston 805, and in conjunction with the hydraulic oil injected into the third port 811, to ensure that the rubber core 803 maintains tight contact with the outer wall of the tubing string, achieving live lifting and lowering.

[0039] In practical applications, such as Figure 4As shown, an iron core is provided inside the rubber core 803. The iron core includes several sets of skeletons evenly distributed along the circumference of the rubber core 803. Each set of skeletons includes two hinged metal supports 809. When the ring-jet piston 805 rises, the hinged joints of the metal supports 809 contract inward, providing a stronger contraction force and better realizing pressurized operation.

[0040] In practical applications, the two metal supports 809 are of the same length, and the ends of the metal supports 809 abut against the upper and lower metal fixing plates 806 respectively. The metal supports 809 and the metal fixing plates 806 abut against each other in a rigid contact, ensuring that the multiple sets of metal supports 809 on the circumference can bend synchronously when the ring injection piston 805 rises and falls, avoiding uneven deformation in various places.

[0041] In practical applications, the cross-section of the metal fixing plate 806 is Z-shaped, and an arc groove is provided at the Z-shaped corner. The end of the metal support 809 has an arc-shaped profile. The end of the metal support 809 abuts against the arc groove of the metal fixing plate 806. The arc groove plays a limiting role for the metal support 809, but does not restrict the free rotation of the metal support 809. Moreover, no additional assembly is required during installation, and the metal support 809 can rotate freely within a limited range.

[0042] In practical applications, the thickness of the middle part of the rubber core 803 is greater than the thickness of its top and bottom ends. Because the middle part of the rubber core 803 comes into contact with the tool and is prone to wear, sufficient rubber allowance is required.

[0043] In summary, the pressurized lifting and lowering of the tubing string of the present invention achieves dynamic sealing adjustment through the coordinated control of three oil injection ports and the annular blowout preventer 8.

[0044] like Figure 5 As shown, a hydraulic station 14 is also provided, which includes a diesel engine, a gear pump 1401, a plunger pump 1402, a pressure gauge control panel, a cooling fan, an accumulator 1403, control valves, oil pipelines, an oil tank, a diesel tank, and other components. The hydraulic station 14 uses a diesel engine as a power source. The gear pump 1401 is suitable for low-pressure delivery. Therefore, the outlet of the gear pump 1401 is connected to the rodless chamber of the lifting cylinder 1 through a hydraulic pipeline.

[0045] like Figure 6 As shown, there are two gear pumps 1401 connected in parallel. One is used for high flow rate and relatively low pressure oil supply, and the other is used for low flow rate and relatively high pressure oil supply. The inlets of both gear pumps 1401 are connected to the oil tank, and the outlets are connected to the pressure oil circuit P1 respectively.

[0046] like Figure 7As shown, this solution employs a plunger pump 1402. The reciprocating motion of the plunger in the plunger pump 1402 compresses and expands the liquid within the pump chamber, thereby achieving suction and discharge. When the plunger moves outward, the liquid within the pump chamber is compressed, causing the outlet valve to open and the liquid to flow out through the outlet. Conversely, when the plunger moves inward, the volume within the pump chamber expands, causing the inlet valve to open and the liquid to be drawn into the pump chamber. The plunger pump 1402 has advantages such as high operating pressure, large flow rate, and good stability, thus meeting the requirements of applications such as slips and blowout preventers.

[0047] The plunger pump 1402 requires a high outlet pressure. Six accumulators 1403 are connected via pipelines. Hydraulic oil from the tank enters the plunger pump 1402 through the inlet valve and filter, pressurizing the hydraulic oil before it is stored in the accumulators 1403. Each accumulator 1403 consists of six cylinders pre-filled with nitrogen at 7 MPa. When the oil pressure in the cylinders of accumulator 1403 reaches 21 MPa, the plunger pump 1402 stops operating. When the oil pressure in the cylinders drops to a set value, the plunger pump 1402 automatically restarts to replenish the cylinders with pressurized oil. This ensures that the cylinders in accumulator 1403 always maintain the required oil pressure.

[0048] The pressurized oil in accumulator cylinder 1403 enters the control manifold and splits into two paths: one path reduces the oil pressure to 10.5 MPa via a manual pressure reducing valve, and then supplies it through pressure oil circuit P2 and valve group to the manifold controlling the hydraulic gate blowout preventer and the reversing valve. Operating the handle of the reversing valve allows for the opening and closing of the corresponding blowout preventer. The other path reduces the oil pressure to 10.5 MPa via a pressure reducing valve, and then supplies it through pressure oil circuit P3 to port P of the first annular blowout reversing valve Y7 controlling the annular blowout preventer 8.

[0049] like Figure 8 As shown, the pressure oil circuit P1 is connected to the P port of the lifting directional valve Y1, the T port of the lifting directional valve Y1 is connected to the oil tank, the A port of the lifting directional valve Y1 is connected to the lower chamber of each lifting cylinder 1, and the B port of the lifting directional valve Y1 is connected to the upper chamber, i.e., the rod chamber, of each lifting cylinder 1. The lifting directional valve Y1 is a three-position four-way directional valve with a neutral position function of type O.

[0050] The pressure oil circuit P2 is connected to the P port of the lifting control valve Y2. The T port of the lifting control valve Y2 is connected to the oil tank. The lifting control valve Y2 is also a three-position four-way directional valve with a neutral position function of type O. The A port of the lifting control valve Y2 is connected to the left hydraulic control port of the lifting directional valve Y1, and the B port of the lifting control valve Y2 is connected to the right hydraulic control port of the lifting directional valve Y1.

[0051] A lifting cylinder balance valve H1 is provided between port B of the lifting directional valve Y1 and the rod chamber of each lifting cylinder 1. The hydraulic control port of the lifting cylinder balance valve H1 is connected to port A of the lifting directional valve Y1.

[0052] When oil enters the lower chamber of each lifting cylinder 1 and lifts it upward, the P port of the lifting control valve Y2 is connected to the A port, and the B port is connected to the T port. This switches the lifting directional valve Y1 to the left position, connecting the P port of the lifting directional valve Y1 to the A port, and the B port to the T port. The lifting cylinder balance valve H1 is in a throttling state. The oil in the rod chamber of each lifting cylinder 1 returns to the oil tank through the B port and T port of the lifting directional valve Y1 after being throttled by the lifting cylinder balance valve H1.

[0053] When the rod chamber of each lifting cylinder 1 is lowered by oil, the P port of the lifting control valve Y2 is connected to the B port, and the A port is connected to the T port, which switches the lifting directional valve Y1 to the right position, making the P port of the lifting directional valve Y1 connected to the B port, and the A port connected to the T port. The lifting cylinder balance valve H1 is in an upward unidirectional and damped state, and the lower chamber of each lifting cylinder 1 directly returns oil to the oil tank.

[0054] The lifting cylinder 1 supports the movable crossbeam 13 and the movable load-bearing slips 5 and movable anti-overhead slips 6 above it, allowing the tubing string to be pulled out of the wellhead or driven down into the well under well pressure. Both the upper and lower ends of the lifting cylinder 1 have hydraulic buffer structures. The upper part of the piston rod of the lifting cylinder 1 has a tapered shaft end for easy alignment and disassembly. The support flange of the lifting cylinder 1 is located at the top of the lifting cylinder 1 and connected to the upper crossbeam 3, in a suspended installation. The stress distribution is optimized, making the cylinder less prone to bending under stress.

[0055] When the wellbore pressure exceeds the lifting force or downward thrust, the lifting cylinder balance valve H1 stabilizes the speed of lifting cylinder 1, preventing excessive load from causing hydraulic cylinder runaway. The pilot oil circuit of the lifting cylinder balance valve H1 is connected between the lower chamber of lifting cylinder 1 and port B of the lifting directional valve Y1. In the event of a blow-through (air intake and pressure loss at the lower chamber of lifting cylinder 1), when the pilot oil circuit pressure returns to normal, the lifting cylinder balance valve H1 can only flow in one direction, meaning the hydraulic oil can only flow from bottom to top, not from top to bottom. Therefore, the return oil at the lower chamber of lifting cylinder 1 is closed, preventing the cylinder from moving upwards and avoiding blow-through. When the pilot oil circuit pressure is 2~3.5MPa, the lifting cylinder balance valve H1 operates in a throttling state with both vertical flow. Adding a balance cylinder effectively prevents blow-through.

[0056] like Figure 9 As shown, the pressure oil circuit P3 is connected to the P port of the first annular injection directional valve Y7. The first annular injection directional valve Y7 is a three-position four-way directional valve with a neutral position function of type O. The T port of the first annular injection directional valve Y7 is connected to the oil tank. The A port of the first annular injection directional valve Y7 is connected to the first oil port 807 of the annular release nozzle 8 through the left path of the annular injection hydraulic lock ZD1. The B port of the first annular injection directional valve Y7 is connected to the second oil port 808 of the annular release nozzle 8 through the right path of the annular injection hydraulic lock ZD1. The annular injection hydraulic lock ZD1 includes two check valves. The hydraulic control port of the left check valve is connected to the inlet of the right check valve, and the hydraulic control port of the right check valve is connected to the inlet of the left check valve.

[0057] The A port of the first ring-jet directional valve Y7 is also connected to the P port of the second ring-jet directional valve Y8. The T port of the second ring-jet directional valve Y8 is connected to the oil tank. The second ring-jet directional valve Y8 is a two-position three-way directional valve. The A port of the second ring-jet directional valve Y8 is connected to the third oil port 811. In this hydraulic circuit, the third oil port 811 can only be pressurized when the first oil port 807 is pressurized, ensuring sequential extrusion of the rubber core 803, reducing wear on the rubber core 803, and extending its service life.

[0058] When the annular blowout 8 needs to be sealed, firstly, the P port of the first annular blowout directional valve Y7 is connected to the A port, and the B port is connected to the T port. Oil enters through the first oil port 807 and exits through the second oil port 808. The annular blowout piston 805 moves upward, and the rubber core 803 is compressed to seal the outer circumference of the tubing. At this time, even if the A and B ports of the first annular blowout directional valve Y7 lose pressure, both the left and right paths of the annular blowout hydraulic lock ZD1 are closed, ensuring the reliable sealing of the annular blowout 8.

[0059] In the case of poor sealing, the P port of the second ring spray reversing valve Y8 is connected to the A port, the third oil port 811 is pressurized, and the rubber core 803 further contracts inward to seal the outer circumference of the tubing. When the annular blower needs to be opened, firstly, port A and port T of the second annular blower reversing valve Y8 are connected, and the third oil port 811 is depressurized first; then, port P and port B of the first annular blower reversing valve Y7 are connected, and port A and port T are connected. The first oil port 807 and the second oil port 808 switch the oil circuit direction, oil enters through the second oil port 808, oil exits through the first oil port 807, the annular blower piston 805 descends, and the rubber core 803 returns to its original state.

[0060] like Figure 10 As shown, the outlet of the plunger pump 1402 is connected to the movable load-bearing slip 5, the movable anti-jacking slip 6, and the fixed slip group 9 via the pressure oil circuit P2, as detailed below: The pressure oil circuit P2 is connected to the P port of the movable slip directional valve Y3. The movable slip directional valve Y3 is a three-position four-way solenoid directional valve with a neutral position function of type O. The T port of the movable slip directional valve Y3 is connected to the oil tank. The A port of the movable slip directional valve Y3 is connected to the rodless chamber of the cylinder of the movable load-bearing slip 5 and the movable anti-jacking slip 6 through the left path of the movable slip hydraulic lock ZD2 and the second hydraulic control check valve Q2. The B port of the movable slip directional valve Y3 is connected to the rod chamber of the cylinder of the movable load-bearing slip 5 and the movable anti-jacking slip 6 through the right path of the movable slip hydraulic lock ZD2.

[0061] The pressure oil circuit P2 is connected to the P port of the fixed slip directional valve Y4. The fixed slip directional valve Y4 is a three-position four-way solenoid directional valve with a neutral position function of type O. The T port of the fixed slip directional valve Y4 is connected to the oil tank. The A port of the fixed slip directional valve Y4 is connected to the rodless chamber of the cylinder of the fixed slip assembly 9 through the left path of the fixed slip hydraulic lock ZD3. The B port of the fixed slip directional valve Y4 is connected to the rod chamber of the cylinder of the fixed slip assembly 9 through the right path of the fixed slip hydraulic lock ZD3 and the first hydraulic control check valve Q1.

[0062] The hydraulic control port of the first hydraulic control check valve Q1 is connected to the rodless chamber oil circuit of the movable load-bearing slip 5 and the movable anti-top slip 6, and the hydraulic control port of the second hydraulic control check valve Q2 is connected to the rodless chamber oil circuit of the cylinder of the fixed slip assembly 9.

[0063] When the cylinder rodless chamber of the fixed slip assembly 9 is pressurized, the second hydraulic control check valve Q2 can be opened upward, allowing pressurized oil to enter the cylinder rod chamber of the movable load-bearing slip 5 and the movable anti-jacking slip 6; only when the fixed slip assembly 9 is tightened can the movable load-bearing slip 5 and the movable anti-jacking slip 6 be released.

[0064] When the cylinder rodless chamber of the movable load-bearing slip 5 and the movable anti-jacking slip 6 is pressurized, the first hydraulic control check valve Q1 can be opened upward, and the pressurized oil can enter the cylinder rod chamber of the fixed slip group 9. Only when the movable load-bearing slip 5 and the movable anti-jacking slip 6 are clamped can the fixed slip group 9 be released.

[0065] The fixed slip assembly 9 mainly works in conjunction with the moving slip assembly to complete tubing tripping operations. In the case of a heavy tubing string, it prevents the tubing string from falling into the well, and in the case of a light tubing string, it prevents the tubing string from flying out of the wellhead. The fixed slip assembly 9 uses the action of the hydraulic cylinder to clamp the tubing string.

[0066] The movable load-bearing slip 5 and the movable anti-overhead slip 6 are used in conjunction with the fixed slip assembly 9. The movable load-bearing slip 5 and the movable anti-overhead slip 6 are connected to the movable crossbeam 13 via the rotary device 7. As the movable crossbeam 13 rises and falls, it rotates forward, reverses, or stops via the hydraulic motors 15 on both sides and the braking device. In conjunction with the fixed slip assembly 9, it achieves the reversing action of the tube column. At the same time, the movable load-bearing slip 5 and the movable anti-overhead slip 6 can loosen and clamp the tube column, and drive the tube column to rotate under the drive of the hydraulic motor 15.

[0067] When raising or lowering the tubing, the movable load-bearing slip 5 and the movable anti-jacking slip 6 are closed to lock the tubing, which is then raised or lowered by the lifting cylinder 1. The slewing device 7 is rotated by the hydraulic motors 15 on both sides of the crossbeam, and forward and reverse rotation is achieved by switching the oil circuit directional valve, which allows the tubing to rotate in either light or heavy tubing mode.

[0068] The upper crossbeam 3 and the lower crossbeam 4 are connected and fixed by the column 2 and flange. Four wellhead mechanical spiral outriggers are installed at the lower part of the column 2, which are the main load-bearing components. During operation, the lifting / lowering pressure of the tubing and the weight of the equipment are transferred to the ground foundation through the outriggers.

[0069] The functions of the balancing valve and the pressure relief valve in the balancing and pressure relief valve assembly 11 are: to balance / release the pressure between the upper and lower gate valves. This is mainly used when switching tool strings or connecting tubing couplings to balance or release the pressure between the upper and lower working gate valve blowout preventers, thus protecting the blowout preventer components. When the well pressure is low and the annular blowout preventer 8 is in operation, the pressure relief section can also serve to protect personnel from overflow pressure.

[0070] The three-gate integrated blowout preventer 12 is a key component of the well control system. Its main purpose is to control wellhead pressure during drilling, well workover, and well testing, effectively preventing blowout accidents and ensuring safe operation. When there are drill strings in the well, a semi-sealed gate blowout preventer of the appropriate size can be used to seal the annulus between the casing and the tubing or drill string. When there are no tubing or drill strings in the well, a fully sealed gate blowout preventer 1203 can be used to completely seal the wellhead. In an emergency, a shear gate can be used to cut the tubing in the well and completely seal the wellhead. Under well-sealing conditions, drilling fluid circulation, choke blowout, well control, well flushing, and other special operations can be performed through the kill manifold connected to the side outlet of its casing.

[0071] like Figure 11 As shown, the pressure oil circuit P3 is connected to the P port of the balance directional valve Y5, and the output port of the balance directional valve Y5 controls the action of the balance valve through the balance valve hydraulic lock ZD4; the pressure oil circuit P3 is connected to the P port of the pressure relief directional valve Y6, and the output port of the pressure relief directional valve Y6 controls the action of the pressure relief valve through the pressure relief valve hydraulic lock ZD5. Pressure oil circuit P3 is connected to port P of lower semi-sealing directional valve Y9. The output port of lower semi-sealing directional valve Y9 controls the action of lower semi-sealing gate blowout preventer 1201 through lower semi-sealing hydraulic lock ZD6. Pressure oil circuit P3 is connected to port P of safety semi-sealing directional valve Y10. The output port of safety semi-sealing directional valve Y10 controls the action of safety semi-sealing gate blowout preventer 1202 through safety semi-sealing hydraulic lock ZD7. Pressure oil circuit P3 is connected to port P of full-sealing directional valve Y11. The output port of full-sealing directional valve Y11 controls the action of full-sealing gate blowout preventer 1203 through full-sealing hydraulic lock ZD8.

[0072] like Figures 12 to 15As shown, the rotary device 7 includes an intermediate connecting seat 711, a rotary gear 705, and a lower bushing 706. The rotary gear 705 and the lower bushing 706 are mounted in the intermediate connecting seat 711 via bearings. The rotary gear 705 and the lower bushing 706 are fixedly connected and can rotate relative to the intermediate connecting seat 711. The movable load-bearing slip 5 and the movable anti-top slip 6 adopt a conical clamping structure. The intermediate connecting seat 711 is fixed to the movable crossbeam 13. The intermediate connecting seat 711 has a release oil inlet 701 and a release return oil outlet 702 on both sides. Oil port 704, clamp release oil inlet 701 is connected to the axially arranged oil inlet main pipe 702 inside the intermediate connecting seat 711, the oil inlet main pipe 702 is connected to the upper first oil hole and the lower second oil hole inside the intermediate connecting seat 711; clamp release oil return port 704 is connected to the axially arranged oil return main pipe 703 inside the intermediate connecting seat 711, the oil return main pipe 703 and the oil inlet main pipe 702 are symmetrical about the center of the intermediate connecting seat 711, the oil return main pipe 703 is connected to the upper third oil hole and the lower fourth oil hole inside the intermediate connecting seat 711; The lower cylindrical surface of the rotary gear 705 is provided with a first groove and a second groove. The first groove is connected to the first oil hole of the intermediate connecting seat 711, and the second groove is connected to the third oil hole of the intermediate connecting seat 711. An L-shaped upper oil inlet branch pipe 709 is provided inside one side of the rotary gear 705, and the upper oil inlet branch pipe 709 is connected to the first groove. An L-shaped upper oil return branch pipe 710 is provided inside the other side of the rotary gear 705, and the upper oil return branch pipe 710 is connected to the second groove. The rotary gear 705 is connected to the movable load-bearing slip 5, and the upper oil inlet branch pipe 709 and the upper oil return branch pipe 710 are connected to the slip seat of the movable load-bearing slip 5. The lower bushing 706 has a third groove and a fourth groove on its cylindrical surface. The third groove is connected to the second oil hole of the intermediate connecting seat 711, and the fourth groove is connected to the fourth oil hole of the intermediate connecting seat 711. An L-shaped lower oil inlet branch pipe 707 is provided inside one side of the lower bushing 706, and the lower oil inlet branch pipe 707 is connected to the third groove. An L-shaped lower oil return branch pipe 708 is provided inside the other side of the lower bushing 706, and the lower oil return branch pipe 708 is connected to the fourth groove. The lower bushing 706 is connected to the movable anti-top slip 6, and the lower oil inlet branch pipe 707 and the lower oil return branch pipe 708 are connected to the slip seat of the movable anti-top slip 6.

[0073] The inner hole of the intermediate connecting seat 711 is provided with a fifth groove, a sixth groove, a seventh groove, an eighth groove, a ninth groove, and a tenth groove, which are filled with sealing rings to prevent leakage of hydraulic oil used for clamping control. After the central connecting seat is installed and fitted with the rotary gear 705 and the lower bushing 706, the fifth groove is located above the second groove, the sixth groove is located between the second groove and the first groove, and the seventh groove is located below the first groove; the eighth groove is located above the third groove, the ninth groove is located between the third groove and the fourth groove, and the ninth groove is located below the fourth groove.

[0074] When using traditional methods to raise and lower tubing strings, a tubing string lifting clamp is required. Because the clamp is suspended by a wire rope, its lifting trajectory is unstable and prone to swaying, often damaging the tubing string. This invention provides a working method for a pressurized tubing string raising and lowering device. The hydraulic cylinder has a working stroke of 3-3.5 meters, and the tubing string length is 7.62 meters or 9.14 meters. The tubing string is raised and lowered completely through three smooth lifts. Multiple lifts reduce the need for a large hydraulic cylinder stroke, resulting in a smaller height and footprint during transport. Simultaneously, during lifting at the tubing string connection, the rubber core of the annular blowout preventer 8 is opened for protection. Opening is achieved through the balanced pressure relief valve assembly 11, preventing pressure shock from the downhole high pressure on the lower half-sealed gate blowout preventer 1201. The specific method is as follows: S1. Close the movable load-bearing clamp 5, close the movable anti-top clamp 6, and clamp the upper part of the pipe column; S2. Close the annular blowout preventer 8, open the balance valve in the balance relief valve group 11 to introduce downhole pressure, so that the pressure in the upper and lower chambers of the lower half-sealed gate blowout preventer 1201 is equal; open the lower half-sealed gate blowout preventer 1201, open the fixed slip group 9, and loosen the lower part of the tubing string. S3, the lifting cylinder 1 moves upward, and the tubing passes through the rubber core 803 of the annular blowout preventer 8 and is lifted; S4. Close the lower half-sealed gate blowout preventer 1201 and close the balance valve in the balance relief valve group 11; S5. Close the fixed slip group 9 and clamp the already lifted pipe column; open the movable load-bearing slip 5 and the movable anti-overhead slip 6, and release the pipe column using the movable load-bearing slip 5 and the movable anti-overhead slip 6. S6. Lifting cylinder 1 descends to its minimum stroke to continue lifting the tubing column.

[0075] Furthermore, it also includes the following steps: S7. Repeat S1-S6 cycle until the connection of the two tubing columns rises below the rubber core 803 of the annular blowout preventer 8. To avoid damage to the rubber core of the annular blowout preventer 8 by the tubing column connection with a larger diameter, close the lower half-sealing gate blowout preventer 1201, open the pressure relief valve of the balance pressure relief valve group 11 to release the oil pressure, then open the annular blowout preventer 8, lift the hydraulic cylinder 1 upward, and the connection of the tubing column passes through the annular blowout preventer 8. S8. Close the annular blowout preventer 8, close the pressure relief valve of the balance pressure relief valve group 11, open the balance valve in the balance pressure relief valve group 11, introduce downhole pressure, so that the pressure in the upper and lower chambers of the lower half-sealed gate blowout preventer 1201 is equal; then open the lower half-sealed gate blowout preventer 1201 to avoid pressure shock to the lower half-sealed gate blowout preventer 1201. S9. Close the fixing slip group 9 to clamp the next section of the tubing; S10. Open the movable load-bearing slip 5 and the movable anti-top slip 6. Rotate the pipe column using hydraulic power clamps and place the dislodged pipe column into the pipe column conveyor using a hook for pipe column recovery. S11. Lifting cylinder 1 descends to its minimum stroke, closes the moving load-bearing slip 5, closes the moving anti-overhead slip 6, clamps the upper part of the next section of the pipe column, and begins lifting and lowering the next section of the pipe column. Repeat the above steps.

[0076] The above description is merely a preferred embodiment of the present invention, showing and describing the basic principles, main features, and advantages of the present invention. It is not intended to limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. In addition to the above embodiments, the present invention may have other implementations without departing from the spirit and scope of the invention. Various changes and modifications to the present invention are possible, and all technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents. Technical features not described in the present invention can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A device for lifting and lowering a tubing string under pressure, characterized in that: It includes multiple lifting cylinders (1), which are installed inside the column (2). The upper and lower ends of the column (2) are fixedly connected by the upper crossbeam (3) and the lower crossbeam (4), respectively. The lifting piston of the lifting cylinder (1) supports the moving crossbeam (13). A rotating device (7) is installed at the center of the moving crossbeam (13). A moving load-bearing slip (5) is installed above the rotating device (7), and a moving anti-top slip (6) is installed below the rotating device (7). The lower crossbeam (4) is installed from top to bottom with an annular blowout preventer (8), a fixed slip group (9), a safety slip group (10), and a three-gate integrated blowout preventer (12).

2. The pressurized lifting and lowering device for tubing as described in claim 1, characterized in that: The side of the safety slip assembly (10) is connected to a balance pressure relief valve assembly (11), which includes a balance valve and a pressure relief valve. The three-gate integrated blowout preventer (12) includes a lower half-sealed gate blowout preventer (1201), a safety half-sealed gate blowout preventer (1202), and a fully sealed gate blowout preventer (1203).

3. The pressurized lifting and lowering pipe string operation device according to claim 1, characterized in that: The annular blowout preventer (8) includes a lower housing (801), a middle housing (810), a top cover (802), a rubber core (803), a dustproof ring (804), and an annular blowout piston (805). The annular blowout piston (805) has a Z-shaped cross-section. The rubber core (803) is a cylindrical shape that is thick at both ends and thin in the middle. Its outer and inner surfaces are both arc-shaped curved surfaces with concave edges. The upper and lower ends of the rubber core (803) are connected to metal fixing plates (806). The upper and lower metal fixing plates (806) of the rubber core (803) abut against the annular blowout piston (805) and the top cover (802) respectively. There is a cavity between the outer surface of the rubber core (803) and the middle housing (810).

4. The pressurized lifting and lowering pipe string operation device according to claim 3, characterized in that: The bottom of the lower housing (801) is provided with a first oil port (807) that communicates with the bottom of the ring injection piston (805), and the upper side wall of the lower housing (801) is provided with a second oil port (808) that communicates with the upper part of the ring injection piston (805).

5. The pressurized lifting and lowering pipe string operation device according to claim 4, characterized in that: The middle shell (810) is provided with a third oil port (811) in the middle, which communicates with the outer peripheral cavity of the rubber core (803).

6. The pressurized lifting and lowering device for tubing as described in claim 5, characterized in that: During normal use, oil enters through the first oil port and exits through the second oil port, causing the ring-jet piston (805) to press the rubber core (803) upward; if the blockage is not achieved within the set time, hydraulic oil is injected through the third oil port.

7. The pressurized lifting and lowering pipe string operation device according to claim 3, characterized in that: The core (803) contains an iron core, which includes several sets of skeletons evenly distributed along the circumference of the core (803). Each set of skeletons includes two hinged metal supports (809).

8. The pressurized lifting and lowering pipe string operation device according to claim 7, characterized in that: The two metal supports (809) are of the same length, and the ends of the metal supports (809) abut against the upper and lower metal fixing plates (806) respectively.

9. The pressurized lifting and lowering device for tubing as described in claim 7, characterized in that: The metal fixing plate (806) has a Z-shaped cross section and an arc groove is provided at the Z-shaped corner. The end of the metal support (809) has an arc-shaped profile and the end of the metal support (809) abuts against the arc groove of the metal fixing plate (806).

10. The pressurized lifting and lowering device for tubing as described in claim 3, characterized in that: The thickness of the middle part of the adhesive core (803) is greater than the thickness of the upper and lower ends of the adhesive core (803).

11. The pressurized lifting and lowering device for tubing as described in claim 3, characterized in that: Two seals are respectively provided between the metal fixing plate (806), the ring-jet piston (805), and the top cover (802).

12. The pressurized lifting and lowering pipe string operation device according to claim 2, characterized in that: A hydraulic station (14) is also provided, which is equipped with a gear pump (1401) and a piston pump (1402). The gear pump (1401) is provided with two units connected in parallel. One unit is used for high flow rate and relatively low pressure oil supply, and the other unit is used for low flow rate and relatively high pressure oil supply. The inlets of the two gear pumps are connected to the oil tank, and the outlets are connected to the pressure oil circuit P1 respectively. The outlet pipe of the plunger pump (1402) is connected to multiple accumulators (1403) and is connected to pressure oil circuits P2 and P3 through a pressure reducing valve group.

13. The pressurized lifting and lowering device for tubing as described in claim 12, characterized in that: The pressure oil circuit P1 is connected to the P port of the lifting directional valve (Y1), the T port of the lifting directional valve (Y1) is connected to the oil tank, the A port of the lifting directional valve (Y1) is connected to the lower chamber of each lifting cylinder (1), and the B port of the lifting directional valve (Y1) is connected to the upper chamber, i.e., the rod chamber, of each lifting cylinder (1). The lifting directional valve (Y1) is a three-position four-way directional valve and the middle position function is type O. The pressure oil circuit P2 is connected to the P port of the lifting control valve (Y2), the T port of the lifting control valve (Y2) is connected to the oil tank, the lifting control valve (Y2) is a three-position four-way directional valve and the neutral position function is type O, the A port of the lifting control valve Y2 is connected to the left hydraulic control port of the lifting directional valve Y1, and the B port of the lifting control valve Y2 is connected to the right hydraulic control port of the lifting directional valve Y1.

14. The pressurized lifting and lowering device for tubing as described in claim 13, characterized in that: A lifting cylinder balance valve (H1) is provided between port B of the lifting directional valve (Y1) and the rod chamber of each lifting cylinder (1). The hydraulic control port of the lifting cylinder balance valve (H1) is connected to port A of the lifting directional valve (Y1). When the lower chamber of each lifting cylinder (1) is filled with oil and lifted upward, the P port of the lifting control valve (Y2) is connected to the A port and the B port is connected to the T port, so that the lifting directional valve (Y1) is switched to the left position, so that the P port of the lifting directional valve (Y1) is connected to the A port and the B port is connected to the T port, and the lifting cylinder balance valve (H1) is in the throttling connected state. The oil in the rod chamber of each lifting cylinder (1) is throttled by the lifting cylinder balance valve (H1) and then returns to the oil tank through the B port and T port of the lifting directional valve (Y1). When the rod chamber of each lifting cylinder (1) is lowered by oil, the P port of the lifting control valve (Y2) is connected to the B port, and the A port is connected to the T port, so that the lifting directional valve (Y1) is switched to the right position, so that the P port of the lifting directional valve (Y1) is connected to the B port, and the A port is connected to the T port, and the lifting cylinder balance valve (H1) is in an upward unidirectional and damped state, and the lower chamber of each lifting cylinder (1) directly returns oil to the oil tank.

15. The pressurized lifting and lowering device for tubing as described in claim 12, characterized in that: The pressure oil circuit P3 is connected to the P port of the first ring injection directional valve (Y7). The first ring injection directional valve (Y7) is a three-position four-way directional valve with a neutral position function of type O. The T port of the first ring injection directional valve (Y7) is connected to the oil tank. The A port of the first ring injection directional valve (Y7) is connected to the first oil port (807) of the annular blower (8) through the left path of the ring injection hydraulic lock (ZD1). The B port of the first ring injection directional valve (Y7) is connected to the second oil port (808) of the annular blower (8) through the right path of the ring injection hydraulic lock (ZD1).

16. The pressurized lifting and lowering device for tubing as described in claim 15, characterized in that: The A port of the first ring injection directional valve (Y7) is also connected to the P port of the second ring injection directional valve (Y8). The T port of the second ring injection directional valve (Y8) is connected to the oil tank. The second ring injection directional valve (Y8) is a two-position three-way directional valve. The A port of the second ring injection directional valve (Y8) is connected to the third oil port (811) of the annular blower (8).

17. The pressurized lifting and lowering device for tubing as described in claim 16, characterized in that: When the annular blower (8) needs to be sealed, firstly, the P port of the first annular blower reversing valve (Y7) is connected to the A port, and the B port is connected to the T port. Oil enters through the first oil port (807) and exits through the second oil port (808). The annular blower piston (805) moves upward, and the rubber core (803) is squeezed to seal the outer periphery of the tube column. In the event of a poor seal, the P port of the second ring spray directional valve (Y8) is connected to the A port, the third oil port (811) builds pressure, and the rubber core (803) further contracts inward to seal the outer periphery of the tubing.

18. The pressurized lifting and lowering device for tubing as described in claim 16, characterized in that: When the annular blower (8) needs to be opened, firstly, the A port of the second annular blower reversing valve (Y8) is connected to the T port, and the third oil port (811) is depressurized first; then the P port of the first annular blower reversing valve (Y7) is connected to the B port, the A port is connected to the T port, the second oil port (808) is filled with oil, the first oil port (807) is filled with oil, the annular blower piston (805) descends, and the rubber core (803) returns to its original state.

19. The pressurized lifting and lowering device for tubing as described in claim 1, characterized in that: The rotary device (7) includes an intermediate connecting seat (711), a rotary gear (705), and a lower bushing (706). The rotary gear (705) and the lower bushing (706) are mounted in the intermediate connecting seat (711) by bearings. The rotary gear (705) and the lower bushing (706) are fixedly connected and can rotate relative to the intermediate connecting seat (711). The movable load-bearing slip (5) and the movable anti-top slip (6) adopt a conical clamping structure. The intermediate connecting seat (711) is fixed to the movable crossbeam (13). The intermediate connecting seat (711) is provided with a loosening oil inlet (701) and a loosening oil inlet (706) on both sides. The clamped oil return port (704) and the loosened oil inlet port (701) are connected to the axially arranged oil inlet main pipe (702) inside the intermediate connecting seat (711). The oil inlet main pipe (702) is connected to the upper first oil hole and the lower second oil hole inside the intermediate connecting seat (711). The loosened oil return port (704) is connected to the axially arranged oil return main pipe (703) inside the intermediate connecting seat (711). The oil return main pipe (703) and the oil inlet main pipe (702) are symmetrical about the center of the intermediate connecting seat (711). The oil return main pipe (703) is connected to the upper third oil hole and the lower fourth oil hole inside the intermediate connecting seat (711). The lower cylindrical surface of the rotary gear (705) is provided with a first groove and a second groove. The first groove is connected to the first oil hole of the intermediate connecting seat (711), and the second groove is connected to the third oil hole of the intermediate connecting seat (711). An L-shaped upper oil inlet branch pipe (709) is provided inside one side of the rotary gear (705), and the upper oil inlet branch pipe (709) is connected to the first groove. An L-shaped upper oil return branch pipe (710) is provided inside the other side of the rotary gear (705), and the upper oil return branch pipe (710) is connected to the second groove. The rotary gear (705) is connected to the movable load-bearing slip (5), and the upper oil inlet branch pipe (709) and the upper oil return branch pipe (710) are connected to the slip seat of the movable load-bearing slip (5). The lower bushing (706) has a third groove and a fourth groove on its cylindrical surface. The third groove is connected to the second oil hole of the intermediate connecting seat (711), and the fourth groove is connected to the fourth oil hole of the intermediate connecting seat (711). An L-shaped lower oil inlet branch pipe (707) is provided inside one side of the lower bushing (706), and the lower oil inlet branch pipe (707) is connected to the third groove. An L-shaped lower oil return branch pipe (708) is provided inside the other side of the lower bushing (706), and the lower oil return branch pipe (708) is connected to the fourth groove. The lower bushing (706) is connected to the movable anti-top slip (6), and the lower oil inlet branch pipe (707) and the lower oil return branch pipe (708) are connected to the slip seat of the movable anti-top slip (6).

20. The pressurized lifting and lowering device for tubing as described in claim 19, characterized in that: The inner hole of the intermediate connecting seat (711) is provided with a fifth groove, a sixth groove, a seventh groove, an eighth groove, a ninth groove and a tenth groove, and the inside is filled with a sealing ring to prevent the leakage of hydraulic oil used for the release control; after the central connecting seat is installed and fitted with the rotary gear (705) and the lower bushing (706), the fifth groove is located above the second groove, the sixth groove is located between the second groove and the first groove, and the seventh groove is located below the first groove; The eighth groove is located above the third groove, and the ninth groove is located between the third and fourth grooves, with the ninth groove located below the fourth groove.

21. The pressurized lifting and lowering device for tubing as described in claim 12, characterized in that: The pressure oil circuit P2 is connected to the P port of the movable slip directional valve (Y3). The movable slip directional valve (Y3) is a three-position four-way solenoid directional valve with a neutral position function of type O. The T port of the movable slip directional valve (Y3) is connected to the oil tank. The A port of the movable slip directional valve (Y3) is connected to the rodless chamber of the cylinder of the movable load-bearing slip (5) and the movable anti-top slip (6) through the left path of the movable slip hydraulic lock (ZD2) and the second hydraulic control check valve (Q2). The B port of the movable slip directional valve (Y3) is connected to the rod chamber of the cylinder of the movable load-bearing slip (5) and the movable anti-top slip (6) through the right path of the movable slip hydraulic lock (ZD2). The pressure oil circuit P2 is connected to the P port of the fixed slip directional valve (Y4). The fixed slip directional valve (Y4) is a three-position four-way solenoid directional valve with a neutral position function of type O. The T port of the fixed slip directional valve (Y4) is connected to the oil tank. The A port of the fixed slip directional valve (Y4) is connected to the rodless chamber of the cylinder of the fixed slip assembly (9) through the left path of the fixed slip hydraulic lock (ZD3). The B port of the fixed slip directional valve (Y4) is connected to the rod chamber of the cylinder of the fixed slip assembly (9) through the right path of the fixed slip hydraulic lock (ZD3) and the first hydraulic control check valve (Q1). The hydraulic control port of the first hydraulic control check valve (Q1) is connected to the rodless chamber oil circuit of the movable load-bearing slip (5) and the movable anti-top slip (6), and the hydraulic control port of the second hydraulic control check valve (Q2) is connected to the oil circuit of the rodless chamber oil circuit of the cylinder of the fixed slip assembly (9).

22. The pressurized lifting and lowering device for tubing as described in claim 21, characterized in that: When the cylinder rodless chamber of the fixed slip assembly (9) is pressurized, the second hydraulic check valve (Q2) can be opened upward, and the pressurized oil can enter the cylinder rod chamber of the movable load-bearing slip (5) and the movable anti-top slip (6); when the fixed slip assembly (9) is tightened, the movable load-bearing slip (5) and the movable anti-top slip (6) can be loosened. When the cylinder rodless chamber of the movable load-bearing slip (5) and the movable anti-overhead slip (6) is pressurized, the first hydraulic check valve (Q1) can be opened upward, and the pressurized oil can enter the cylinder rod chamber of the fixed slip assembly (9). Only when the movable load-bearing slip (5) and the movable anti-overhead slip (6) are tightly clamped can the fixed slip assembly (9) be released.

23. The method of operation of the pressurized lowering and lowering pipe string working device according to any one of claims 1 to 22, characterized in that, Includes the following steps: S1. Close the movable load-bearing clamp (5), close the movable anti-top clamp (6), and clamp the upper part of the pipe column; S2. Close the annular blowout preventer (8), open the balance valve in the balance relief valve group (11) to introduce downhole pressure, so that the pressure in the upper and lower chambers of the lower half-sealed gate blowout preventer (1201) is equal; open the lower half-sealed gate blowout preventer (1201), open the fixed slip group (9) to loosen the lower part of the tubing string; S3, the lifting cylinder (1) moves upward, and the tubing passes through the rubber core (803) of the annular blowout preventer (8) and is lifted; S4. Close the lower half-sealed gate blowout preventer (1201) and close the balance valve in the balance relief valve group (11); S5. Close the fixed clamping slip group (9) and clamp the already lifted pipe column; open the movable load-bearing clamp (5), open the movable anti-overhead clamp (6), and release the pipe column using the movable load-bearing clamp (5) and the movable anti-overhead clamp (6); S6. The lifting cylinder (1) descends to its minimum stroke to continue lifting the tubing column.

24. The working method of the pressurized lowering and lowering pipe string operation device according to claim 23, characterized in that, It also includes the following steps: S7. Repeat S1-S6 cycle until the connection of the two tubing columns rises below the rubber core (803) of the annular blowout preventer (8). To avoid damage to the rubber core of the annular blowout preventer (8) by the tubing column connection with a larger diameter, close the lower half-sealing gate blowout preventer (1201), open the pressure relief valve of the balance pressure relief valve group (11) to release the oil pressure, and then open the annular blowout preventer (8). Lift the oil cylinder (1) upward, and the connection of the tubing column passes through the annular blowout preventer (8). S8. Close the annular blowout preventer (8), close the pressure relief valve of the balance relief valve group (11), open the balance valve in the balance relief valve group (11), introduce downhole pressure, so that the pressure in the upper and lower chambers of the lower half-sealed gate blowout preventer (1201) is equal; then open the lower half-sealed gate blowout preventer (1201) to avoid pressure shock to the lower half-sealed gate blowout preventer (1201); S9. Close the fixed slip assembly (9) and clamp the next section of the tubing; S10. Open the movable load-bearing clamp (5), open the movable anti-top clamp (6), rotate the pipe column by hydraulic power clamp, and put the dislodged pipe column into the pipe column conveyor by hook for pipe column recovery. S11. The lifting cylinder (1) descends to the minimum stroke, closes the moving load-bearing slip (5), closes the moving anti-top slip (6), clamps the upper part of the next section of the pipe column, and performs the lifting and lowering of the next section of the pipe column. Repeat the above steps.

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