Remote pneumatic control cement head and its pneumatic blocking pin assembly

Abstract

The application provides a remote pneumatic control cement head and a pneumatic blocking pin assembly thereof. The pneumatic blocking pin assembly comprises a cylinder barrel, a mounting seat, a first piston and a blocking rod. The cement head comprises at least one above-mentioned pneumatic blocking pin assembly, a shell, a top cover, a manifold, at least one plug valve assembly and at least one rubber plug. The application has the beneficial effects that the rubber plug can be remotely operated to complete the operations of plug delivery, circulation, isolation fluid injection, cement slurry injection and mud replacement, and the operator can be away from the high-pressure area of the wellhead, thereby improving personal safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas equipment, in particular to a remote pneumatic control cement head and a pneumatic blocking pin assembly thereof, which are used for cementing operation of oil and gas wells. BACKGROUND

[0002] The cement head is a special high-pressure wellhead tool used for connecting the casing string and the cementing equipment to complete the cementing operation. Through the cement head, the circulation, isolation fluid injection, cement slurry injection, plug releasing, and slurry replacement operations can be completed, and the cement head is the key hub of the ground manifold wellhead in the cementing operation. Among the several core components of the cement head, the spiral blocking pin is used to block the plug, the nipple is used to connect with the cement injection pipeline and the slurry replacement pipeline, and the plug valve is used to control the passage and closing of the fluid. The blocking pin assembly of the cement head is the most important component of the cement head, and the remote control of the blocking pin assembly of the cement head is the prerequisite for the remote control of the cement head. Most of the existing conventional cement heads adopt a spiral blocking pin mechanism, which is connected through a large pitch thread and an outer cylinder. It needs to rotate the hand wheel for several or even dozens of times to completely withdraw the blocking pin to release the plug, which is time-consuming. When the casing is connected and cemented, the cement head needs to be operated at a high altitude, which increases the safety risk of personnel. When the pipeline is switched, the plug valve needs to be manually opened and closed, which has a high-pressure operation risk.

[0003] For example, a rotary cement head is disclosed in Chinese Patent No. CN105317395A, which includes: a body provided with a hollow chamber to guide the cement slurry into the cementing casing; a top cover provided at the top end of the body, which can be connected to a hanging clamp to rotate the cement head with the drilling tool; a nipple interface including a first nipple interface and a second nipple interface, both of which are in fluid communication with the chamber, the first nipple interface and the second nipple interface are provided on the upper part of the body, and the first nipple interface is closer to the top cover, the first nipple interface can be connected to the slurry replacement pipeline, and the second nipple interface can be connected to the cement injection pipeline; a spiral blocking pin provided on the body and located between the first nipple interface and the second nipple interface, which can retain the plug in the chamber, and release the plug downward when the plug is replaced. Although this rotary cement head has a simple structure and is easy to operate, it still uses a spiral blocking pin mechanism and cannot achieve remote control.

[0004] Due to the increasing well depth, the length of the cementing pipe string is correspondingly increased, and the pump pressure of the cementing construction is higher and higher, which has a high risk in the construction operation. Therefore, it is urgent to upgrade and reform the cement head.

[0005] Therefore, it is necessary to upgrade the conventional cement head to an automatic one, and to develop a remote pneumatic control cement head. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application aims to solve one or more of the problems existing in the prior art. For example, one of the purposes of the present application is to enable remote operation to complete the operations of rubber plug delivery, circulation, isolation fluid injection, cement slurry injection, and mud replacement; the second purpose is to enable the operator to be away from the high-pressure area of the wellhead, thereby improving personal safety.

[0007] In order to achieve the above-mentioned purposes, in one aspect, the present application provides a pneumatic blocking pin assembly for a remote pneumatic control cement head.

[0008] The pneumatic blocking pin assembly can include a cylinder barrel, a mounting seat, a first piston, and a blocking rod. The cylinder barrel can have a first cavity arranged axially and opened to the right, and left and right air inlets can be radially arranged through the cylinder barrel. The left end of the mounting seat and the right end of the cylinder barrel can be fixedly and sealingly arranged to close the opening of the first cavity, and the right end can be fixedly connected with the cement head. The mounting seat can be axially provided with a first through hole. The first piston can be arranged in the first cavity to divide the first cavity into a left gas chamber and a right gas chamber. The blocking rod can be arranged axially in the right gas chamber, and the left end thereof can be fixedly connected with the right end of the first piston, and the right end thereof can pass through the first through hole to form a dynamic seal. The left air inlet is in communication with the left gas chamber to supply gas to the left gas chamber to push the first piston and the blocking rod to move to the right, and the right air inlet is in communication with the right gas chamber to supply gas to the right gas chamber to push the first piston and the blocking rod to move to the left.

[0009] Further, the pneumatic blocking pin assembly can further include a drive shaft and a drive nut. The left end of the cylinder barrel can be axially provided with a second through hole, and the first piston can be axially provided with a third through hole. The drive nut can be fixedly arranged at the entrance of the third through hole. The left end of the drive shaft passes through the second through hole and forms a dynamic seal, and the right end thereof passes through the drive nut and enters the third through hole. The right end of the drive shaft can be provided with threads matched with the drive nut, and the drive shaft can rotate along its axis while driving the first piston to move axially in the first cavity.

[0010] Further, the first piston can include a first segment and a second segment. The first segment forms a dynamic seal with the inner wall of the cylinder barrel, and the outer diameter of the second segment is smaller than that of the first segment. The third through hole can pass through the first segment and the second segment.

[0011] Further, the blocking rod can be axially provided with a fourth through hole, and the fourth through hole is in communication with the third through hole. The pneumatic blocking pin assembly can further include a pressure balance mechanism arranged in the third through hole and the fourth through hole to balance the pressure in the cement head.

[0012] Further, the pressure balance mechanism can include a second piston, a hollow screw and a balance piston. The second piston can be arranged in the third through hole and forms a dynamic seal with the third through hole and is in contact with the right end of the drive shaft. The balance piston can be arranged in the fourth through hole and forms a dynamic seal with the fourth through hole. The hollow screw can be arranged at the connection between the third through hole and the fourth through hole, and the balance hole can be arranged on the hollow screw. The left hydraulic oil cavity is formed between the inner wall of the third through hole, the right end of the second piston and the left end of the hollow screw. The right hydraulic oil cavity is formed between the inner wall of the fourth through hole, the left end of the balance piston and the right end of the hollow screw. The balance hole connects the left hydraulic oil cavity and the right hydraulic oil cavity.

[0013] Further, the right end of the stop rod can be provided with a limiting nut to prevent the balance piston from falling out of the fourth through hole.

[0014] Further, the left end of the drive shaft can be further provided with a shaft shoulder, which can limit the position of the drive shaft in the first cavity, so that the drive shaft can only rotate and cannot move left and right.

[0015] Further, the pneumatic stop pin assembly can further include a first buffer pad and a second buffer pad. The first buffer pad can be arranged on the right side of the shaft shoulder, and the second buffer pad can be arranged on the left side of the mounting seat.

[0016] Further, the pneumatic stop pin assembly can further include a knob plunger. The left side of the cylinder barrel can be radially provided with a mounting hole, and the knob plunger can be arranged in the mounting hole and can lock the drive shaft and the cylinder barrel to prevent the drive shaft from rotating accidentally.

[0017] Further, the pneumatic stop pin assembly can further include a crowbar. The left end of the drive shaft can be radially provided with a crowbar insertion hole, and the crowbar can be inserted into the crowbar insertion hole to manually rotate the drive shaft.

[0018] In order to achieve the above-mentioned purpose, another aspect of the present application provides a remote pneumatic control cement head.

[0019] The cement head can include at least one above-mentioned remote pneumatic control cement head pneumatic blocking pin assembly, and a shell, a top cover, a manifold, at least one plug valve assembly and at least one rubber plug. Wherein, the shell can be vertically arranged, and a fifth through hole can be arranged on the shell in the axial direction; the top cover is fixedly and sealingly arranged with the upper end of the shell to close the upper end of the fifth through hole; one end of each plug valve assembly of the at least one plug valve assembly is in communication with the inside of the shell, and the other end is in communication with the manifold; the pneumatic blocking pin assembly can be fixedly installed on the shell and arranged vertically with the shell, and the blocking rod of the pneumatic blocking pin assembly can enter the fifth through hole to intercept the rubber plug; when the pneumatic blocking pin assembly includes two or more, the two or more pneumatic blocking pin assemblies are arranged on the shell from top to bottom at intervals; the at least one rubber plug can be arranged in the fifth through hole, and the number of the rubber plug corresponds to the number of the pneumatic blocking pin assembly, and the rubber plug is located above the blocking rod of the corresponding pneumatic blocking pin assembly.

[0020] Further, the cement head can further include a rubber plug indicator, which can be installed in the shell and located below the pneumatic blocking pin assembly.

[0021] Further, the plug valve assembly can include a plug valve air inlet.

[0022] Further, the left air inlet and the right air inlet of the cylinder barrel body can be provided with a first pneumatic actuator; the plug valve air inlet can be provided with a second pneumatic actuator.

[0023] Further, the cement head can further include a pneumatic control box, which can include at least one set of left air inlet switch and right air inlet switch of the cylinder barrel body, and at least one set of plug valve air inlet switch, wherein the left air inlet switch and the right air inlet switch of the cylinder barrel body control the corresponding first pneumatic actuator respectively; the plug valve air inlet switch controls the second pneumatic actuator.

[0024] Compared with the prior art, the beneficial effects of the present application can include at least one of the following:

[0025] (1) The present application can allow the operator to remotely operate the control box, that is, to operate on the drilling platform surface away from the wellhead or the well site ground, and to remotely complete the rubber plug launching, plug valve switching.

[0026] (2) The present application can remotely operate to complete the rubber plug launching, circulation, isolation fluid injection, cement slurry injection, mud replacement and other operations.

[0027] (3) The present application allows the operator to be away from the high-pressure dangerous area, avoids the risk of falling from a high place, and improves the operation safety.

[0028] (4) The present application has a rubber plug falling indication function, and the rubber plug falling process can be remotely observed. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the present application, the drawings needed in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0030] Figure 1 A structural schematic diagram showing that the blocking rod of the pneumatic blocking pin assembly of the present application is in an extended state;

[0031] Figure 2 A structural schematic diagram showing that the blocking rod of the pneumatic blocking pin assembly of the present application is in a retracted state;

[0032] Figure 3 A structural schematic diagram showing a remote pneumatic control cement head of the present application;

[0033] Figure 4 Another structural schematic diagram showing a remote pneumatic control cement head of the present application;

[0034] Figure 5 A structural schematic diagram showing a pneumatic control box of the present application;

[0035] Figure 6 A schematic diagram showing a pneumatic control system interface of the present application.

[0036] Main figure mark explanation:

[0037] 1-pneumatic blocking pin assembly, 101-cylinder barrel, 1011-left air inlet, 1012-right air inlet, 1013-left air cavity, 1014-right air cavity; 102-mounting seat; 103-first piston; 104-blocking rod; 105-driving shaft; 106-driving nut; 107-second piston; 108-hollow screw; 109-balancing piston; 110-balancing hole; 111-left hydraulic oil cavity; 112-right hydraulic oil cavity; 113-limiting nut; 114-shoulder; 115-first buffer pad; 116-second buffer pad; 117-knob plunger; 118-prying lever insertion hole;

[0038] 2-housing, 201-fifth through hole; 3-top cover; 4-manifold; 5-stop valve assembly, 501-stop valve open air inlet, 502-stop valve close air inlet; 6-rubber plug; 7-rubber plug indicator; 8-pneumatic control box;

[0039] 1A - first pneumatic stop pin assembly, 1011A - first pneumatic stop pin assembly left air inlet, 1012A - first pneumatic stop pin assembly right air inlet; 1B - second pneumatic stop pin assembly, 1011B - second pneumatic stop pin assembly left air inlet, 1012B - second pneumatic stop pin assembly right air inlet;

[0040] 5A - first stopcock valve assembly, 501A - first stopcock valve open air inlet, 502A - first stopcock valve close air inlet; 5B - second stopcock valve assembly, 501B - second stopcock valve open air inlet, 502B - second stopcock valve close air inlet; 5C - third stopcock valve assembly, 501C - third stopcock valve open air inlet, 502C - third stopcock valve close air inlet;

[0041] 6A - first rubber plug, 6B - second rubber plug;

[0042] 801A - first pneumatic stop pin assembly left air inlet interface, 802A - first pneumatic stop pin assembly right air inlet interface; 801B - second pneumatic stop pin assembly left air inlet interface, 802B - second pneumatic stop pin assembly right air inlet interface;

[0043] 803A - first stopcock valve open air inlet interface, 804A - first stopcock valve close air inlet interface;

[0044] 803B - second stopcock valve open air inlet interface, 804B - second stopcock valve close air inlet interface;

[0045] 803C - third stopcock valve open air inlet interface, 804C - third stopcock valve close air inlet interface. DETAILED DESCRIPTION

[0046] The technical solutions of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application. The contents not described in detail in the embodiments of the present application are the prior art known to those skilled in the art.

[0047] It should be noted that "first", "second", "third" and the like are only for the convenience of description and distinguishing, and cannot be understood as indicating or implying relative importance. "Up", "down", "front", "back", "left", "right", "inner", "outer" and the like are only for the convenience of description and constitute relative position relationship, and do not indicate or imply that the components must have the specific position.

[0048] Example Embodiment 1

[0049] The present exemplary embodiment provides a pneumatic blocking pin assembly for a remote pneumatic control cement head. The present exemplary embodiment will be described below in conjunction with Figure 1 and Figure 2 .

[0050] As shown in Figure 1 and Figure 2 , the pneumatic blocking pin assembly 1 can include a cylinder barrel 101, a mounting base 102, a first piston 103, and a blocking rod 104. The cylinder barrel 101 can have a first cavity axially arranged and open to the right, and the cylinder barrel 101 can further have a left gas inlet 1011 and a right gas inlet 1012 radially penetrating therethrough. The left end of the mounting base 102 can be fixedly and sealingly arranged with the right end of the cylinder barrel 101, thereby closing the opening of the first cavity. The right end of the mounting base 102 can be fixedly connected with the cement head, and the mounting base 102 can have a first through hole axially arranged thereon. The first piston 103 can be arranged in the first cavity to divide the first cavity into a left gas chamber 1013 and a right gas chamber 1014. The blocking rod 104 can be axially arranged in the right gas chamber 1014, and the left end of the blocking rod 104 can be fixedly connected with the right end of the first piston 103. The right end of the blocking rod 104 can pass through the first through hole of the mounting base 102 and form a dynamic seal with the first through hole. The left gas inlet 1011 can communicate with the left gas chamber 1013 to supply gas to the left gas chamber 1013 to push the first piston 103 and the blocking rod 104 to move to the right. The right gas inlet 1012 can communicate with the right gas chamber 1014 to supply gas to the right gas chamber 1014 to push the first piston 103 and the blocking rod 104 to move to the left. When the blocking rod 104 moves to the left in the first cavity, the rubber plug in the cement head is normally released. When the blocking rod 104 moves to the right in the first cavity, the right end of the blocking rod 104 enters the cement head to prevent the release of the rubber plug.

[0051] In the present embodiment, the cylinder barrel 101 and the mounting base 102 can be connected by threads, and a sealing ring and a locking screw can be installed at the connection. Of course, the present application is not limited thereto, and the connection between the cylinder barrel 101 and the mounting base 102 can also be other ways that can achieve the fixed and sealing connection. The right end of the mounting base 102 and the cement head can be fixedly connected by a connecting screw to achieve the installation of the pneumatic blocking pin assembly 1 and the cement head. Of course, the present application is not limited thereto, and the connection between the mounting base 102 and the cement head can also be other ways that can achieve the fixed connection.

[0052] In the present embodiment, as shown in Figure 1As shown, the pneumatic blocking pin assembly 1 can further include a drive shaft 105 and a drive nut 106. The left end of the cylinder barrel 101 can be axially provided with a second through hole, and the first piston 103 can be axially provided with a third through hole. The drive nut 106 can be fixedly arranged at the entrance of the third through hole. The left end of the drive shaft 105 passes through the second through hole and forms a dynamic seal with the second through hole, and the right end of the drive shaft 105 passes through the drive nut 106 and enters the third through hole. The right end of the drive shaft 105 can be provided with threads matched with the drive nut 106, and the drive shaft 105 can drive the first piston 103 to move axially in the first cavity while rotating along its own axis.

[0053] Specifically, the drive shaft 105, the drive nut 106 and the first piston 103 constitute a driving mechanism. The external threads of the right end of the drive shaft 105 and the internal threads of the drive nut 106 are matched to form a non-self-locking threaded pair, which can be multi-start trapezoidal threads or triangular threads. When the first piston 103 is driven to move linearly to the left or to the right, the drive shaft 105 will rotate; when the drive shaft 105 is driven to rotate, the first piston 103 will move linearly to the left or to the right.

[0054] In this embodiment, as shown, Figure 1 The first piston 103 can include a first section and a second section. The outer diameter of the first section is matched with the inner wall of the cylinder barrel 101 to form a dynamic seal, and the outer diameter of the second section is smaller than that of the first section. The third through hole can pass through the first section and the second section and be arranged axially along the first piston 103.

[0055] Specifically, the first section is arranged to ensure that the first piston 103 divides the first cavity of the cylinder barrel 101 into a left gas cavity 1013 and a right gas cavity 1014, and the second section is arranged to ensure that when the first piston 103 moves to the right to the limit state, i.e., the right end abuts against the left end of the mounting seat 102, the right gas cavity 1014 still has a certain space, and the position of the right air inlet 1012 should be within the radial position range corresponding to the second section in the limit state, and the right gas cavity 1014 can be ventilated through the right air inlet 1012.

[0056] In this embodiment, as shown, Figure 1 The blocking rod 104 can be axially provided with a fourth through hole, and the fourth through hole is in communication with the third through hole. The pneumatic blocking pin assembly 1 can further include a pressure balance mechanism, which can be arranged in the third through hole and the fourth through hole to balance the pressure in the cement head.

[0057] In this embodiment, as shown, Figure 1As shown, the pressure balancing mechanism can include a second piston 107, a hollow screw 108, and a balancing piston 109. The second piston 107 can be arranged in the third through hole and forms a dynamic seal with the third through hole and is in contact with the right end of the drive shaft 105. The balancing piston 109 can be arranged in the fourth through hole and forms a dynamic seal with the fourth through hole. The hollow screw 108 can be arranged at the connection between the third through hole and the fourth through hole, and the balancing hole 110 can be arranged on the hollow screw 108. The left hydraulic oil cavity 111 is formed between the inner wall of the third through hole, the right end of the second piston 107, and the left end of the hollow screw 108. The right hydraulic oil cavity 112 is formed between the inner wall of the fourth through hole, the left end of the balancing piston 109, and the right end of the hollow screw 108. The balancing hole 110 connects the left hydraulic oil cavity 111 and the right hydraulic oil cavity 112.

[0058] Specifically, the left hydraulic oil cavity 111, the balancing hole 110, and the right hydraulic oil cavity 112 are in communication, forming a sealed hydraulic oil cavity that can transmit the pressure in the cement head body and block the liquid in the cement head. When there is high-pressure fluid in the cement head body (the pressure can be as high as 105 MPa), the balancing piston 109 will be compressed to move to the left, and the balancing piston 109 will compress the hydraulic oil on the left side, so that the volume of the hydraulic oil cavity decreases and the pressure increases, and finally reaches a balance with the pressure in the cement head body. By balancing the pressure in the cement head body through the balancing mechanism, it can be ensured that the first piston 103 can be pushed to move linearly to the left or to the right under normal air pressure (about 0.8 MPa), thereby driving the stopper 104 to extend to the right or retract to the left.

[0059] In this embodiment, as shown in Figure 1 The right end of the stopper 104 can be provided with a limiting nut 113 to prevent the balancing piston 109 from falling out of the fourth through hole. Specifically, when the pressure in the cement head body disappears, the balancing piston 109 moves to the right to restore its original state. The limiting nut 113 is connected with the stopper 104 by threads, and the limiting nut can prevent the balancing piston 109 from falling out and play a limiting role.

[0060] In this embodiment, as shown in Figure 1 and Figure 2 The left end of the drive shaft 105 can also be provided with a shaft shoulder 114, which can limit the position of the drive shaft 105 in the first cavity, so that it can only rotate and cannot move left and right.

[0061] Specifically, the shaft shoulder 114 is arranged to limit the driving shaft 105, so that the driving shaft 105 cannot move left and right, but can only rotate along the axis of the driving shaft 105. When the first piston 103 moves to the left limit state, the shaft shoulder 114 can leave a certain space for the left air chamber 1013, and the left air inlet 1011 should be located in the radial position range corresponding to the shaft shoulder 114, and air can be introduced into the left air chamber 1013 through the left air inlet 1011.

[0062] In the embodiment, as shown in Figure 1 and Figure 2 , the pneumatic stop pin assembly 1 can further include a first buffer pad 115 and a second buffer pad 116. The first buffer pad 115 can be arranged on the right side of the shaft shoulder 114, and the second buffer pad 116 can be arranged on the left side of the mounting base 102.

[0063] Specifically, when the first piston 103 moves to the left limit state, the first buffer pad 115 limits and reduces the impact. When the first piston 103 moves to the right limit state, the second buffer pad 116 limits and reduces the impact.

[0064] In the embodiment, as shown in Figure 1 , the pneumatic stop pin assembly 1 can further include a knob plunger 117. A mounting hole (not shown in the figure) can be arranged radially on the left side of the cylinder barrel 101, and a recess or opening for accommodating the knob plunger 117 can be arranged on the driving shaft 105. The knob plunger 117 is arranged in the mounting hole and inserted into the recess or opening on the driving shaft 105, so as to lock the driving shaft 105 and the cylinder barrel 101, and prevent the driving shaft 105 from rotating accidentally.

[0065] Specifically, the knob plunger 117 prevents the cement head from being misoperated. When the cement head does not put the rubber plug, the knob plunger 117 is inserted into the mounting hole of the cylinder barrel 101 and reaches the recess or opening on the driving shaft 105, so as to prevent the driving shaft 105 from rotating accidentally and moving the stop lever 104 to the left to move away from the initial position and block the rubber plug. When the preparation work is completed and it is determined that the rubber plug needs to be put, the knob plunger 117 can be lifted, and at this time, the knob plunger 117 no longer limits the rotation of the driving shaft 105, so that the rubber plug can be put normally.

[0066] In the embodiment, as shown in Figure 1 , the pneumatic stop pin assembly 1 can further include a crowbar (not shown in the figure). A crowbar insertion hole 118 can be arranged radially on the left end of the driving shaft 105, and the crowbar can be inserted into the crowbar insertion hole 118 to manually rotate the driving shaft 105.

[0067] Specifically, the lever is inserted into the lever insertion hole 118, and the drive shaft 105 is manually rotated clockwise or counterclockwise, which drives the first piston 103 to move in a straight line in a spiral manner, and drives the blocking rod 104 to extend or retract. This manual function is a backup function, which can be used to complete the plug injection when the pneumatic control system fails.

[0068] In this embodiment, the pneumatic blocking pin assembly 1 can also include a plurality of sealing rings arranged at the connecting parts of the components that need to be sealed, such as the connecting part of the first piston 103 and the cylinder barrel 101, the connecting part of the second piston 107 and the first piston 103, the connecting part of the cylinder barrel 101 and the mounting base 102, etc.

[0069] Example 2

[0070] This example provides a remote pneumatic control cement head, which is described below in combination with Figure 1 and Figure 6 .

[0071] As Figures 1 to 3 shown, the cement head can include at least one pneumatic blocking pin assembly 1 of the above example 1, and a shell 2, a top cover 3, a manifold 4, at least one plug valve assembly 5, and at least one rubber plug 6. The shell 2 can be vertically arranged, and the shell 2 can be provided with a fifth through hole 201 in the axial direction. The top cover 3 is fixedly and sealingly arranged at the upper end of the shell 2 to close the upper end of the fifth through hole 201. One end of each plug valve assembly 5 of the at least one plug valve assembly 5 is in communication with the inside of the shell 2, and the other end is in communication with the manifold 4. The pneumatic blocking pin assembly 1 can be fixedly installed on the shell 2 and arranged perpendicularly to the shell 2, and the blocking rod 104 of the pneumatic blocking pin assembly 1 can enter the fifth through hole 201 to intercept the rubber plug 6. When the pneumatic blocking pin assembly 1 includes two or more, the two or more pneumatic blocking pin assemblies 1 are arranged on the shell 2 from top to bottom at intervals. The at least one rubber plug 6 can be arranged in the fifth through hole 201, and the number of rubber plugs 6 corresponds to the number of pneumatic blocking pin assemblies 1, and the rubber plug 6 is located above the blocking rod 104 of the corresponding pneumatic blocking pin assembly 1.

[0072] Specifically, the top cover 3 can be connected to the shell 2 by threads, and each time the rubber plug 6 is installed, the top cover 3 can be removed for installation. In the initial state, the blocking rod 104 extends to the right to the limit state to block the downward movement of the rubber plug 6. When the blocking rod 104 is retracted to the left to the limit state, the rubber plug 6 can move downward.

[0073] In this embodiment, as Figure 1 and Figure 3As shown, the cement head can further include a plug indicator 7, which can be installed in the housing 2 and below the pneumatic blocking pin assembly 1. Specifically, when the blocking rod 104 is retracted to the limit state to the left, the plug 6 is pushed downward by the fluid, which can compress the plug indicator 7 and transmit an indication of the successful launching of the plug 6 to the operator.

[0074] In the present embodiment, as shown in Figure 3 The cock valve assembly 5 can include a cock valve air inlet. The cock valve air inlet includes a cock valve open air inlet 501 and a cock valve close air inlet 502. The cock valve air inlet can be provided with a second pneumatic actuator. Specifically, the second pneumatic actuator can realize the control switch by controlling the air inlet direction.

[0075] In the present embodiment, the left air inlet 1011 and the right air inlet 1012 of the cylinder barrel 101 can be provided with a first pneumatic actuator. Specifically, the first pneumatic actuator can realize the control switch by controlling the air inlet direction.

[0076] In the present embodiment, the cement head can further include a pneumatic control box 8 as shown in Figure 5 The pneumatic control box 8 can include at least one set of left air inlet switch and right air inlet switch of the cylinder barrel 101, and at least one set of cock valve air inlet switch. Among them, the left air inlet switch and the right air inlet switch of the cylinder barrel 101 control the corresponding first pneumatic actuator; the cock valve air inlet switch controls the second pneumatic actuator.

[0077] In order to better understand the above-mentioned exemplary embodiments of the present application, the following will be combined with Example 1 and Figures 4 to 6 Further illustrate the present application.

[0078] Example 1

[0079] Example 1 illustrates in detail how the present application realizes pneumatic remote control with a double-plug cement head.

[0080] The cement head can include two pneumatic blocking pin assemblies, two plugs and three cock valve assemblies. Among them, as shown in Figure 4 The two pneumatic blocking pin assemblies can include a first pneumatic blocking pin assembly 1A and a second pneumatic blocking pin assembly 1B; the two plugs can include a first plug 6A and a second plug 6B; and the three cock valve assemblies can include a first cock valve assembly 5A, a second cock valve assembly 5B and a third cock valve assembly 5C.

[0081] Figure 6 The schematic diagram of the pneumatic control system interface in the direction of the pneumatic control box A is shown in Figure 5 The connection of the interfaces of the pneumatic control system and the pneumatic pipeline includes:

[0082] The first pneumatic blocking pin assembly left air inlet interface 801A is connected with the first pneumatic blocking pin assembly left air inlet 1011A, and the first pneumatic blocking pin assembly right air inlet interface 802A is connected with the first pneumatic blocking pin assembly right air inlet 1012A;

[0083] The second pneumatic blocking pin assembly left air inlet interface 801B is connected with the second pneumatic blocking pin assembly left air inlet 1011B, and the second pneumatic blocking pin assembly right air inlet interface 802B is connected with the second pneumatic blocking pin assembly right air inlet 1012B;

[0084] The first plug valve open air inlet interface 803A is connected with the first plug valve open air inlet 501A, and the first plug valve close air inlet interface 804A is connected with the first plug valve close air inlet 502A;

[0085] The second plug valve open air inlet interface 803B is connected with the second plug valve open air inlet 501B, and the second plug valve close air inlet interface 804B is connected with the second plug valve close air inlet 502B;

[0086] The third plug valve open air inlet interface 803C is connected with the third plug valve open air inlet 501C, and the third plug valve close air inlet interface 804C is connected with the third plug valve close air inlet 502C.

[0087] The working process of the remote pneumatic control cement head of example 1 includes but is not limited to the following contents:

[0088] After the cement head is installed at the well mouth, the pneumatic pipelines of the pneumatic control box 8 are connected with the corresponding interfaces respectively. When the second rubber plug 6B needs to be put, the blocking rod of the second pneumatic blocking pin assembly 1B is retracted by operating the pneumatic control box 8, the second plug valve assembly 5B is opened, the fluid enters from the manifold 4, flows into the main channel through the second plug valve assembly 5B, drives the second rubber plug 6B to descend, compresses the rubber plug indicator 7, and transmits the indication of the successful putting of the second rubber plug 6B to the operator. When the first rubber plug 6A needs to be put, the blocking rod of the first pneumatic blocking pin assembly 1A is retracted by operating the pneumatic control box 8, the first plug valve assembly 5A is opened, the fluid enters from the manifold 4, flows into the main channel through the first plug valve assembly 5A, drives the first rubber plug 6A to descend, compresses the rubber plug indicator 7, and transmits the indication of the successful putting of the first rubber plug 6A to the operator.

[0089] The cement head can realize the sequential injection of isolation fluid, cement slurry and displacement fluid through different opening and closing combinations of the three plug valve assemblies.

[0090] Example 1 only takes the double rubber plug cement head as an example for detailed description, and of course the present application is not limited thereto, but also applicable to single rubber plug cement head and multiple rubber plug cement head.

[0091] In summary, the remote pneumatic control cement of the present application overcomes the shortcomings of the conventional screw type check pin mechanism cement head technology. The cement head is configured with a pneumatic control system, and the pneumatic check pin assembly and the plug valve assembly are both controlled by the pneumatic control box, and the pneumatic check pin assembly is designed with a pressure balance mechanism, which can ensure the extension and retraction of the stop rod in the pneumatic check pin assembly under normal air pressure. The pneumatic check pin assembly and the plug valve assembly are matched with pneumatic actuators, and by operating the handle on the pneumatic control box, the launching of the rubber plug and the switching of the plug valve can be remotely completed. In well cementing operations, the present application can remotely and quickly launch the rubber plug, improve the construction efficiency and operation safety, and through different switching combinations of multiple plug valves, the sequential injection of spacer fluid, cement slurry and displacement fluid can be realized.

[0092] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical range disclosed by the present application can be easily thought of by those skilled in the art, and should belong to the protection scope of the technical solution of the present application.

Claims

1. A pneumatic stop pin assembly for remotely pneumatically controlling a cement head, characterized in that, The pneumatic stop pin assembly includes a cylinder body, a mounting base, a first piston, and a stop rod, wherein... The cylinder body has a first cavity that is axially arranged and opens to the right, and a left air inlet and a right air inlet are radially arranged through the cylinder body. The left end of the mounting base is fixedly sealed to the right end of the cylinder body to close the opening of the first cavity, and the right end is fixedly connected to the cement head. The mounting base is provided with a first through hole in the axial direction. The first piston is disposed in the first cavity, dividing the first cavity into a left air chamber and a right air chamber; The stop bar is axially arranged in the right air chamber and its left end is fixedly connected to the right end of the first piston, while its right end passes through the first through hole to form a dynamic seal. The left air inlet is connected to the left air chamber and supplies gas to the left air chamber, pushing the first piston and the stop rod to move to the right; the right air inlet is connected to the right air chamber and supplies gas to the right air chamber, pushing the first piston and the stop rod to move to the left. The pneumatic stop pin assembly also includes a drive shaft and a drive nut. The cylinder body has a second through hole axially arranged at its left end, and the first piston has a third through hole axially arranged on its upper side. The drive nut is fixedly disposed at the entrance of the third through hole. The left end of the drive shaft passes through the second through hole and forms a dynamic seal, while the right end passes through the drive nut and enters the third through hole. The right end of the drive shaft has a thread adapted to the drive nut, enabling the drive shaft to rotate along its own axis while simultaneously driving the first piston to move axially within the first cavity. The first piston includes a first section and a second section, wherein the first section forms a dynamic seal with the inner wall of the cylinder, and the outer diameter of the second section is smaller than the outer diameter of the first section; the third through hole is provided through the first section and the second section. The stop bar is axially provided with a fourth through hole, which communicates with the third through hole; the pneumatic stop pin assembly also includes a pressure balancing mechanism, which is disposed in the third through hole and the fourth through hole to balance the pressure inside the cement head. The pressure balancing mechanism includes a second piston, a hollow screw, and a balance piston. The second piston is disposed in the third through hole, forming a dynamic seal with the third through hole and contacting the right end of the drive shaft. The balance piston is disposed in the fourth through hole and forming a dynamic seal with the fourth through hole. The hollow screw is disposed at the connection between the third through hole and the fourth through hole, and a balance hole is provided on the hollow screw. A left hydraulic oil chamber is formed between the inner wall of the third through hole, the right end of the second piston, and the left end of the hollow screw. A right hydraulic oil chamber is formed between the inner wall of the fourth through hole, the left end of the balance piston, and the right end of the hollow screw. The balance hole connects the left and right hydraulic oil chambers.

2. The pneumatic stop pin assembly for remote pneumatic control of cement heads according to claim 1, characterized in that, A limit nut is provided at the right end of the stop rod to prevent the balance piston from falling out of the fourth through hole.

3. The pneumatic stop pin assembly for remote pneumatic control of cement heads according to claim 1, characterized in that, A shoulder is also provided on the left end of the drive shaft. The shoulder can restrict the position of the drive shaft in the first cavity, so that it can only rotate and cannot move left or right.

4. The pneumatic stop pin assembly for remote pneumatic control of cement heads according to claim 3, characterized in that, The pneumatic stop pin assembly also includes a first buffer pad and a second buffer pad, with the first buffer pad disposed on the right side of the shaft shoulder and the second buffer pad disposed on the left side of the mounting base.

5. The pneumatic stop pin assembly for remote pneumatic control of cement heads according to claim 1, characterized in that, The pneumatic stop pin assembly also includes a knob plunger. A mounting hole is provided radially on the left side of the cylinder body. The knob plunger is disposed in the mounting hole and can lock the drive shaft to the cylinder body to prevent the drive shaft from rotating accidentally.

6. The pneumatic stop pin assembly for remote pneumatic control of cement heads according to claim 1, characterized in that, The pneumatic stop pin assembly also includes a pry bar, and a pry bar insertion hole is radially provided at the left end of the drive shaft. The pry bar can be inserted into the pry bar insertion hole to manually rotate the drive shaft.

7. A remotely pneumatically controlled cement head, characterized in that, The cement head comprises: at least one pneumatic stop pin assembly for remote pneumatic control of the cement head as described in any one of claims 1 to 6, and a housing, a top cover, a manifold, at least one plug valve assembly, and at least one rubber stopper, wherein, The housing is vertically arranged, and a fifth through hole is provided on the housing along the axial direction; The top cover is fixedly and sealed to the upper end of the housing to close the upper end of the fifth through hole; In the at least one plug valve assembly, one end of each plug valve assembly is connected to the interior of the housing, and the other end is connected to the manifold; The pneumatic stop pin assembly is fixedly installed on the housing and is perpendicular to the housing. The stop bar of the pneumatic stop pin assembly can enter the fifth through hole to intercept the rubber plug. When the pneumatic stop pin assembly includes two or more, the two or more pneumatic stop pin assemblies are spaced apart from top to bottom on the housing. At least one rubber plug is disposed in the fifth through hole and the number of rubber plugs corresponds to the number of pneumatic stop pin assemblies. The rubber plug is located above the stop bar of the corresponding pneumatic stop pin assembly.

8. The remote pneumatically controlled cement head according to claim 7, characterized in that, The cement head also includes a rubber stopper indicator, which is installed inside the housing and located below the pneumatic stopper assembly.

9. The remote pneumatically controlled cement head according to claim 7, characterized in that, The plug valve assembly includes a plug valve inlet.

10. The remote pneumatically controlled cement head according to claim 9, characterized in that, The left and right air inlets of the cylinder body are each equipped with a first pneumatic actuator; the air inlet of the plug valve is equipped with a second pneumatic actuator.

11. The remote pneumatically controlled cement head according to claim 10, characterized in that, The cement head also includes a pneumatic control box, which includes at least one set of left and right air inlet switches for the cylinder body, and at least one set of air inlet switches for the rotary valve. The left and right air inlet switches of the cylinder body respectively control the corresponding first pneumatic actuator; The inlet switch of the plug valve controls the second pneumatic actuator.

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