Blowout prevention oil pumping string and hydraulic control valve

Abstract

The utility model discloses a blowout prevention oil pumping string and a hydraulic control valve, which comprise a release, a packer and a hydraulic control valve, and the release, the packer and the hydraulic control valve are sequentially connected from top to bottom; the hydraulic control valve comprises a valve cover, a valve ball, a plug and a valve outer lock body; a valve seat is arranged on the inner wall of the valve cover, the valve ball can be seated on the valve seat, and the plug is arranged below the valve seat to seal the valve cover. The valve outer lock body comprises an unlocking mechanism and a lock block, the lock block is connected with the unlocking mechanism, and the lock block penetrates through the valve cover to be inserted into the plug. When a production pipe column and a sucker rod are put down, the hydraulic control valve closes a stratum, well fluid cannot be sprayed upwards, blowout is avoided, well killing operation is not needed, the problem of oil layer pollution is avoided, the yield of an oil well is not affected, and safe operation can be achieved at a well mouth.

Description

Technical Field

[0001] The utility model relates to the technical field of oil pumping and blowout prevention, in particular to a blowout prevention oil pumping pipe column and a hydraulic control valve. Background Art

[0002] There is a pump on the tubing of the pumping well, and there is an oil inlet valve at the bottom of the pump. The oil inlet valve is a one-way valve, and the well fluid can flow upward from below it, but cannot flow upward from below it. Therefore, during the process of lowering the production tubing, if the wellhead pressure is greater than zero, the well fluid will spray out of the wellhead, causing a serious engineering accident. In order to prevent the above accidents from happening, at present, for the pumping wells that may have blowouts, the only way to prevent blowouts is to use well killing before lowering the production tubing. Well killing is to use a certain density of well killing fluid to drive into the wellbore, so that the liquid column pressure generated in the oil layer is higher than the oil layer pressure, so that the high-pressure well fluid in the oil layer cannot flow into the wellbore, thereby preventing blowouts. Although this method can prevent blowouts, it requires high costs and a long operation construction time. The bigger problem is that the well killing fluid can easily enter the formation, causing formation pollution, blocking the formation pores, and reducing the formation permeability, which seriously affects the production of oil wells.

[0003] Publication (Announcement) No.: CN101832260B discloses an anti-blowout oil inlet valve for a pump, in which a one-way valve is arranged above a plug, which can block the passage of an outer sealing body, and the lower high-pressure well fluid cannot enter above the plug. The plug is unsealed by gravity of a sucker rod, and each component is a one-time action, which can prevent the well fluid from spraying out through the pump when the pump and the sucker rod are lowered.

[0004] Publication (Announcement) No.: CN210949091U, discloses an oil inlet device for a blowout prevention oil pump, in which a one-way valve is arranged below the plug, and the plug is arranged as a connecting joint, a sliding sleeve, and a threaded plug. The plug is unsealed by gravity of the sucker rod, and the sliding sleeve falls on the threaded plug. The liquid flows into the oil pump from the side wall of the connecting joint, thereby avoiding the upward force exerted on the plug by the oil and gas pressure at the bottom of the well, which causes the pump to be closed later due to failure to reach its position.

[0005] Publication (Announcement) No.: CN110080720B discloses a balanced impact blowout preventer, in which the blockage is set to be composed of a switch sleeve and a blowout preventer flow core shaft. After being unsealed by the gravity of the sucker rod, the liquid flows into the oil pump from the blowout preventer flow core shaft, avoiding the upward force of the oil and gas pressure at the bottom of the well on the valve plate, resulting in the phenomenon that the impact pump is not in place and then closed later.

[0006] The above device has a complex structure. It needs to break one or two shear pins by the weight of the sucker rod, and also needs to produce a static fit in the well by the weight of the sucker rod. This requirement is difficult to achieve in the well. Through field tests, it is found that the weight of the sucker rod cannot break the shear pins. Although the weight of the sucker rod is tens of kilonewtons, it seems that it can completely break the shear pins that can only withstand less than 10 kilonewtons of shear force. However, the actual situation is the opposite of the expected result. This is because the buoyancy of the sucker rod column acts on the bottom of the sucker rod, causing the bottom of the sucker rod to bend, so that most of the weight of the sucker rod is transferred to the wall of the oil pipe after being bent. Therefore, the above device cannot achieve the design purpose.

[0007] In short, the technical solutions of the above-disclosed technologies, the technical problems to be solved and the beneficial effects produced are all different from the present utility model. Regarding more technical features, technical problems to be solved and the beneficial effects of the present utility model, there is no technical inspiration in the above-disclosed technical documents. Utility Model Content

[0008] In view of the above-mentioned defects in the prior art, the purpose of the utility model is to provide a blowout-proof pumping pipe string and a hydraulic control valve, which first closes the formation, and when the production pipe string and the pumping rod are lowered, blowout will not occur, and there is no need to take well killing operations, thus avoiding the adverse consequences of well killing and increasing its reliability.

[0009] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0010] On the one hand, the utility model provides a blowout prevention oil pumping string, including a release hand, a packer, and a hydraulic control valve, wherein the release hand, the packer, and the hydraulic control valve are connected in sequence from top to bottom; the hydraulic control valve includes a valve cover, a valve ball, a plug, and a valve external lock body; a valve seat is provided on the inner wall of the valve cover, the valve ball can sit on the valve seat, and the plug closes the valve cover under the valve seat; the valve external lock body includes an unlocking mechanism and a locking block, the locking block is connected to the unlocking mechanism, and the locking block passes through the valve cover and is inserted into the plug.

[0011] Furthermore, a push rod is provided at the upper end of the plug, and the push rod pushes the valve ball away from the valve seat;

[0012] Specifically, an upper joint is threadedly connected to an outer wall of the upper end of the valve cover, and a lower joint is threadedly connected to an outer wall of the lower end of the valve cover.

[0013] Furthermore, a sieve plate is arranged above the valve cover, a limiting boss is arranged on the inner wall of the upper joint, the sieve plate is pressed against the upper end surface of the valve cover by the limiting boss, the sieve plate has sieve holes, and the diameter of the sieve holes is smaller than the diameter of the valve ball.

[0014] Furthermore, a screen pipe is installed at the lower end of the lower joint, a screen slot is provided on the side wall of the screen pipe, a guide head is provided at the lower end of the screen pipe for closure, the lower part of the guide head is conical, and at least two straightening plates are provided on the side wall of the screen pipe.

[0015] Furthermore, the unlocking mechanism includes a sealing sleeve, a spring, an outer cylinder, and an outer shear pin;

[0016] Specifically, the valve cover is provided with a pressure transmission hole above the valve seat, the outer wall of the valve cover is provided with a spring seat below the pressure transmission hole, the spring is sleeved outside the valve cover, and the lower end of the spring sits on the spring seat;

[0017] Specifically, the inner diameter of the sealing sleeve is an upper major diameter and a lower minor diameter, the transition between the upper major diameter and the lower minor diameter is a hydraulic cylinder surface, the upper major diameter of the sealing sleeve is sleeved on the outside of the upper joint from below the upper joint, the lower minor diameter of the sealing sleeve is sleeved on the outside of the valve cover, the hydraulic cylinder surface and the lower end surface of the upper joint form a hydraulic cylinder, the pressure transmission hole connects the hydraulic cylinder with the inside of the valve cover, and the lower end surface of the sealing sleeve is pressed on the upper end surface of the spring, so that the spring is compressed;

[0018] Specifically, the outer cylinder is sleeved on the lower joint and the spring, the upper end of the outer cylinder is threadedly connected to the lower end of the sealing sleeve, the lower end of the outer cylinder is connected to the locking block through an external shear nail, and an unlocking step is provided on the inner wall of the outer cylinder above the external shear nail.

[0019] Furthermore, the unlocking mechanism also includes an open lock ring and a lock ring mounting sleeve;

[0020] Specifically, the lock ring installation sleeve is sleeved outside the valve cover, and the lock ring installation sleeve covers the lock block, so that the lock block cannot be separated from the valve cover after being constrained, the lock ring installation sleeve is seated on the lower joint, and the open lock ring is installed in the groove outside the lock ring installation sleeve, and the open lock ring can expand out of the diameter;

[0021] Specifically, the radial thickness of the locking ring mounting sleeve is greater than the depth of the locking block inserted into the plug;

[0022] Specifically, the lower end of the outer cylinder is connected to the locking ring mounting sleeve through an external shear nail.

[0023] Furthermore, the unlocking mechanism also includes a connecting pin, which passes through the valve cover and is inserted into the blockage.

[0024] Furthermore, an annular groove is provided on the outer wall of the blocking member, both ends of the annular groove are conical, and the shape of the inner wall of the locking block matches the annular groove.

[0025] Furthermore, an upper sealing ring is installed on the outer wall of the upper joint, and a lower sealing ring is installed on the lower diameter of the sealing sleeve. The upper sealing ring and the lower sealing ring seal the hydraulic cylinder together; the downward movement limit of the sealing sleeve will not cause the hydraulic cylinder to release the seal;

[0026] Specifically, the plug is provided with a seal above the locking block and the connecting pin.

[0027] In another aspect, the present invention provides a hydraulic control valve, including a plug, a valve cover, a valve ball, and a valve external lock body; a valve seat is arranged on the inner wall of the valve cover, the valve ball can sit on the valve seat, and the plug closes the valve cover below the valve seat; the valve external lock body includes an unlocking mechanism and a locking block, the locking block is connected to the unlocking mechanism, and the locking block passes through the valve cover and is inserted into the plug.

[0028] Compared with the prior art, the utility model has the following beneficial effects:

[0029] When the blowout-proof sucker pipe string of the utility model is under the production pipe string and the sucker rod, the hydraulic control valve closes the formation, the well fluid cannot spray out upward, blowout will not occur, well killing operation is not needed, there is no problem of oil layer pollution, the oil well production will not be affected, and the wellhead can be operated safely. The utility model has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of a pipe string lowered into a closed formation in an embodiment of the utility model;

[0031] Figure 2 It is a structural schematic diagram of a production pipe string in an embodiment of the utility model;

[0032] Figure 3 It is a structural schematic diagram of the hydraulic control valve in the embodiment of the utility model.

[0033] In the figure: 1. casing; 2. tubing; 3. oil pump; 4. release; 5. packer; 6. hydraulic control valve;

[0034] 4-1. Throw away the upper part of the hand; 4-2. Throw away the lower part of the hand;

[0035] 6-1, upper joint; 6-2, sieve plate; 6-3, upper sealing ring; 6-4, sealing sleeve; 6-5, lower sealing ring; 6-6, spring; 6-7, valve ball; 6-8, outer tube; 6-9, valve cover; 6-9-1, pressure transmission hole; 6-9-2, spring seat; 6-10, plug; 6-11, sealing element; 6-12, open locking ring; 6-13, external shear nail; 6-14, locking ring installation sleeve; 6-15, locking block; 6-16, connecting pin; 6-17, lower joint; 6-18, sieve tube; 6-18-1, sieve slit; 6-19, straightening plate; 6-20, guide head. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] Embodiment 1:

[0038] See also Figures 1 to 3 The utility model provides a blowout prevention pumping string, which is a device for preventing well fluid from spraying to the ground when the oil pipe is pulled up and the production string is lowered in the pumping well, and comprises a release hand 4, a packer 5, and a hydraulic control valve 6 which are sequentially connected from top to bottom;

[0039] The release arm 4 comprises a release arm upper portion 4-1 and a release arm lower portion 4-2. After the bottom of the release arm 4 is sealed, the release arm upper portion 4-1 and the release arm lower portion 4-2 are separated into two parts by pressing from top to bottom. The blowout prevention pumping pipe string is lowered into the casing through the oil pipe 2, and after setting, the oil pipe 2 and the release arm upper portion 4-1 are lifted, and then the production pipe string containing the oil pump 3 is lowered to perform oil production operations.

[0040] The hydraulic control valve 6 comprises a valve cover 6 - 9 , a valve inner plugging body, and a valve outer locking body. The valve outer locking body passes through the valve cover 6 - 9 from outside the valve cover 6 - 9 to lock the valve inner plugging body.

[0041] The inner wall of the valve cover 6-9 is provided with a valve seat, and the inner valve plugging body includes a valve ball 6-7 and a plug 6-10. The valve ball 6-7 can sit on the valve seat, and the plug 6-10 closes the valve cover 6-9 below the valve seat. The outer valve lock body includes an unlocking mechanism and a locking block 6-15. The outer wall of the locking block 6-15 is connected to the unlocking mechanism, and the locking block 6-15 passes through the valve cover 6-9 and is inserted into the plug 6-10.

[0042] A push rod is arranged at the upper end of the plug 6-10, and the push rod pushes the valve ball 6-7 away from the valve seat, so that the upper end of the plug 6-10 is connected with the inside of the valve cover 6-9.

[0043] An upper joint 6-1 is threadedly connected to the outer wall of the upper end of the valve cover 6-9, and a lower joint 6-17 is threadedly connected to the outer wall of the lower end of the valve cover 6-9.

[0044] Specifically, the unlocking mechanism includes a sealing sleeve 6-4, a spring 6-6, an outer cylinder 6-8, an open lock ring 6-12, an outer shear pin 6-13, and a lock ring installation sleeve 6-14;

[0045] The valve cover 6-9 is provided with a pressure transmission hole 6-9-1 above the valve seat, and the outer wall of the valve cover 6-9 is provided with a spring seat 6-9-2 below the pressure transmission hole 6-9-1. The spring 6-6 is sleeved outside the valve cover 6-9, and the lower end of the spring 6-6 sits on the spring seat 6-9-2;

[0046] The inner diameter of the sealing sleeve 6-4 is an upper major diameter and a lower minor diameter, and the transition between the upper major diameter and the lower minor diameter is a hydraulic cylinder surface. The upper major diameter of the sealing sleeve 6-4 is sleeved on the outside of the upper joint 6-1 from the bottom of the upper joint 6-1, and the lower minor diameter of the sealing sleeve 6-4 is sleeved on the outside of the valve cover 6-9. The hydraulic cylinder surface and the lower end surface of the upper joint 6-1 form a hydraulic cylinder. The pressure transmission hole 6-9-1 connects the hydraulic cylinder with the inside of the valve cover 6-9. The lower end surface of the sealing sleeve 6-4 is pressed on the upper end surface of the spring 6-6, so that the spring 6-6 is compressed.

[0047] The locking ring mounting sleeve 6-14 is sleeved on the outside of the valve cover 6-9, and the locking ring mounting sleeve 6-14 wraps the locking block 6-15, so that the locking block 6-15 cannot be separated from the valve cover 6-9 after being constrained. The locking ring mounting sleeve 6-14 sits on the lower joint 6-17, and the open locking ring 6-12 is installed in the groove outside the locking ring mounting sleeve 6-14; the radial thickness of the locking ring mounting sleeve 6-14 is greater than the depth of the locking block 6-15 inserted into the plug 6-10; the open locking ring 6-12 is used to hang the locking ring mounting sleeve 6-14 on the outer tube 6-8, and drive the locking ring mounting sleeve 6-14 to move upward and leave the outer wall of the locking block 6-15, so that the locking block 6-15 can lose its constraint.

[0048] The outer tube 6-8 is sleeved on the lower joint 6-17 and the spring 6-6, the upper end of the outer tube 6-8 is threadedly connected to the lower end of the sealing sleeve 6-4, the lower part of the outer tube 6-8 is connected to the locking ring mounting sleeve 6-14 through the external shear nail 6-13, and the inner wall of the outer tube 6-8 is provided with an unlocking step above the external shear nail 6-13; the spring 6-6 plays the role of supporting the sealing sleeve 6-4 and the outer tube 6-8 to prevent the external shear nail 6-13 from being sheared off during the downhole process.

[0049] By pressing, the sealing sleeve 6-4 moves downward, and the outer tube 6-8 cuts the outer shear nail 6-13. The pressure makes the outer tube 6-8 move further downward, and the unlocking step is located below the open lock ring 6-12. The open lock ring 6-12 swells out, and the pressing is stopped. The outer tube 6-8 moves upward under the influence of the spring 6-6, and the unlocking step is connected with the open lock ring 6-12, so that the lock ring mounting sleeve 6-14 moves upward to make room. Under the pressure of the liquid column, the locking block 6-15 enters the space to release the lock on the plug 6-10. After the valve ball 6-7 falls, it can cooperate with the valve seat to seal and form a one-way flow channel. The liquid can only move from bottom to top, and cannot flow from top to bottom.

[0050] Embodiment 2:

[0051] On the basis of Example 1, the stability of the hydraulic control valve 6 is improved, and a connecting pin 6-16 is provided. The connecting pin 6-16 passes through the valve cover 6-9 and is inserted into the plug 6-10. When the spring 6-6 fails and the locking block 6-15 pops out accidentally, the connecting pin 6-16 acts as a safety.

[0052] In order to improve the pop-out efficiency of the locking block 6-15, an annular groove is provided on the outer wall of the plug 6-10, and the two ends of the annular groove are conical. The shape of the inner wall of the locking block 6-15 matches the annular groove, so that it is easier to insert the locking block 6-15 into the plug 6-10 during assembly. When popping out, the cones at both ends of the annular groove can push the locking block out of the plug 6-10.

[0053] In order to avoid the loss of pressure energy due to the gap, the outer wall of the upper joint 6-1 is installed with an upper sealing ring 6-3 to seal the gap between the upper joint 6-1 and the sealing sleeve 6-4; the lower sealing ring 6-5 is installed on the lower diameter of the sealing sleeve 6-4 to seal the gap between the sealing sleeve 6-4 and the valve cover 6-9; the upper sealing ring 6-3 and the lower sealing ring 6-5 jointly seal the hydraulic cylinder; the downward movement limit of the sealing sleeve 6-4 will not cause the hydraulic cylinder to be unsealed; the plug 6-10 is provided with a sealing member 6-11 above the locking block 6-15 and the connecting pin 6-16, and the sealing member 6-11 seals the gap between the plug 6-10 and the valve cover 6-9.

[0054] In order to prevent the valve ball 6-7 from being too far away from the valve seat, a sieve plate 6-2 is arranged above the valve cover 6-9, and a limiting boss is arranged on the inner wall of the upper joint 6-1. The sieve plate 6-2 is pressed against the upper end surface of the valve cover 6-9 by the limiting boss. The sieve plate 6-2 has sieve holes, and the diameter of the sieve holes is smaller than the diameter of the valve ball 6-7. This arrangement facilitates replacement and cleaning of the sieve plate 6-2. The sieve plate 6-2 prevents the washing fluid from entering the formation when the oil well is washed, thereby protecting the formation from being contaminated.

[0055] In order to improve the service life of the oil pump 3, a screen tube 6-18 is installed at the lower end of the lower joint 6-17, and a screen slit 6-18-1 is provided on the side wall of the screen tube 6-18. A guide head 6-20 is provided at the lower port of the screen tube 6-18 to close it, so that the well fluid can only flow into the screen tube 6-18 through the screen slit 6-18-1. The lower part of the guide head 6-20 is conical, and at least two straightening plates 6-19 are provided on the side wall of the screen tube 6-18.

[0056] Embodiment 3:

[0057] Based on Example 2, this example provides a method for using a blowout prevention pumping string, which specifically includes the following steps:

[0058] S1. Connect the oil pipe 2 to the upper part of the release hand 4-1, and then lower it into the casing 1. The lower part of the casing 1 is connected to the formation. The release hand 4, the packer 5, and the hydraulic control valve 6 are above the formation. The hydraulic control valve 6 seals the bottom to prevent the formation fluid from flowing above the hydraulic control valve 6. Figure 1 As shown;

[0059] S2, pressurize the inside of the tubing 2 from the ground, so that the packer 5 is anchored and sealed, and then the upper part 4-1 of the release arm and the lower part 4-2 of the release arm are disconnected. The packer 5 and the hydraulic control valve 6 separate the casing 1 into two pressure systems, so that the formation fluid cannot flow into the casing 1 above the packer 5, and the tubing 2 and the upper part 4-1 of the release arm are pulled out;

[0060] S3, lower the production string into the casing 1, the production string includes the oil pipe 2 and the oil pump 3, such as Figure 2 As shown;

[0061] S4, the ground presses the inside of the casing 1, and the hydraulic pressure acts on the hydraulic control valve 6, and the hydraulic pressure is transmitted to the sealing sleeve 6-4 through the pressure transmission hole 6-9-1, pushing the outer tube 6-8 to cut the outer shear nail 6-13, and the outer tube 6-8 moves downward, so that the unlocking step is located below the open lock ring 6-12, and the open lock ring 6-12 bulges out;

[0062] Stop pressing, the outer cylinder 6-8 moves up under the influence of the spring 6-6, the unlocking step is connected with the open lock ring 6-12, so that the lock ring installation sleeve 6-14 moves up to make room, and the lock block 6-15 loses its constraint;

[0063] Press again, under the action of pressure, the connecting pin 6-16 is cut off, the locking block 6-15 enters the space, unlocks the plug 6-10, the plug 6-10 falls to the lower part of the screen tube 6-18, the liquid flow channel is opened, and the valve ball 6-7 sits on the valve seat;

[0064] S5, start the oil pump 3, and the formation fluid can flow into the oil pump 3 through the hydraulic control valve 6, the packer 5, and the lower part of the release handle 4-2.

[0065] It should be noted that the packer 5 in the present invention is a prior art, such as a Y445 packer, and those skilled in the art are clear about its use method.

[0066] All components and connection methods of components not discussed in this application belong to the known technologies in this technical field and can be directly applied without further explanation.

[0067] In the present invention, the term "plurality" means two or more than two, unless otherwise clearly defined. The terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0068] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0069] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0070] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A blowout prevention pumping string, including a hand release and a packer, characterized in that: It also includes a hydraulic control valve, wherein the release device, the packer, and the hydraulic control valve are connected in sequence from top to bottom; The hydraulic control valve comprises a valve cover, a valve ball, a plug and a valve outer lock body; The inner wall of the valve housing is provided with a valve seat, the valve ball can sit on the valve seat, and the plug seals the valve housing below the valve seat; The valve outer lock body comprises an unlocking mechanism and a locking block, wherein the locking block is connected to the unlocking mechanism and the locking block is inserted through the valve cover to block the valve.

2. A blowout prevention pumping string according to claim 1, characterized in that: A push rod is arranged at the upper end of the plug, and the push rod pushes the valve ball away from the valve seat; An upper joint is threadedly connected to the outer wall of the upper end of the valve cover, and a lower joint is threadedly connected to the outer wall of the lower end of the valve cover.

3. A blowout prevention pumping string according to claim 2, characterized in that: A sieve plate is arranged above the valve cover, a limiting boss is arranged on the inner wall of the upper joint, the sieve plate is pressed against the upper end surface of the valve cover by the limiting boss, and the sieve plate has sieve holes, the diameter of which is smaller than the diameter of the valve ball.

4. A blowout prevention pumping string according to claim 2, characterized in that: A screen pipe is installed at the lower end of the lower joint, a screen slot is arranged on the side wall of the screen pipe, a guide head is arranged at the lower end of the screen pipe for closure, the lower part of the guide head is conical, and at least two straightening plates are arranged on the side wall of the screen pipe.

5. A blowout prevention pumping string according to any one of claims 2 to 4, characterized in that: The unlocking mechanism includes a sealing sleeve, a spring, an outer cylinder, and an outer shear pin; The valve cover is provided with a pressure transmission hole above the valve seat, and the outer wall of the valve cover is provided with a spring seat below the pressure transmission hole. The spring is sleeved outside the valve cover, and the lower end of the spring sits on the spring seat; The inner diameter of the sealing sleeve is an upper major diameter and a lower minor diameter, and the transition between the upper major diameter and the lower minor diameter is a hydraulic cylinder surface. The upper major diameter of the sealing sleeve is sleeved on the outside of the upper joint from the bottom of the upper joint, and the lower minor diameter of the sealing sleeve is sleeved on the outside of the valve cover. The hydraulic cylinder surface and the lower end surface of the upper joint form a hydraulic cylinder. The pressure transmission hole connects the hydraulic cylinder with the inside of the valve cover, and the lower end surface of the sealing sleeve is pressed on the upper end surface of the spring, so that the spring is compressed; The outer cylinder is sleeved on the lower joint and the spring, the upper end of the outer cylinder is threadedly connected to the lower end of the sealing sleeve, the lower end of the outer cylinder is connected to the locking block through an external shear nail, and an unlocking step is arranged on the inner wall of the outer cylinder above the external shear nail.

6. The blowout prevention pumping string according to claim 5, characterized in that: The unlocking mechanism also includes an open lock ring and a lock ring mounting sleeve; The lock ring installation sleeve is sleeved outside the valve cover, and the lock ring installation sleeve covers the lock block, so that the lock block cannot be separated from the valve cover after being constrained. The lock ring installation sleeve is seated on the lower joint, and the open lock ring is installed in the groove outside the lock ring installation sleeve, and the open lock ring can expand out of the diameter; The radial thickness of the locking ring installation sleeve is greater than the depth of the locking block inserted into the plug; The lower end of the outer cylinder is connected to the lock ring installation sleeve through an external shear nail.

7. The blowout prevention pumping string according to claim 5, characterized in that: The outer wall of the blocking block is provided with an annular groove, both ends of the annular groove are conical, and the shape of the inner wall of the locking block matches the annular groove.

8. The blowout prevention pumping string according to claim 5, characterized in that: The unlocking mechanism also includes a communication pin, which passes through the valve cover and is inserted into the plug.

9. The blowout prevention pumping string according to claim 8, characterized in that: An upper sealing ring is installed on the outer wall of the upper joint, and a lower sealing ring is installed on the lower diameter of the sealing sleeve. The upper sealing ring and the lower sealing ring seal the hydraulic cylinder together; the downward movement limit of the sealing sleeve will not cause the hydraulic cylinder to release the seal; The plug is provided with a sealing member above the locking block and the connecting pin.

10. A hydraulic control valve, comprising a plug, characterized in that It also includes a valve cover, a valve ball, and a valve outer lock body; The inner wall of the valve housing is provided with a valve seat, the valve ball can sit on the valve seat, and the plug seals the valve housing below the valve seat; The valve outer lock body comprises an unlocking mechanism and a locking block, wherein the locking block is connected to the unlocking mechanism and the locking block is inserted through the valve cover to block the valve.

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