A downhole pressure monitoring device

Abstract

The present invention relates to a downhole pressure monitoring device, comprising: an outer tube, which is used to be sent into a wellbore to form a wellbore annulus; a central tube is located in the outer tube and is assembled with the outer tube spiral transmission, and a sealing structure is fixed in the central tube; a slip seat sealing structure includes a cone sleeve and a rubber tube; the central tube moves relative to the outer tube in the up and down directions when rotating forward to compress the rubber tube to deform, and then drive the cone sleeve to move in the direction of the push slip to open; a pressure sensor is used to monitor the fluid pressure in the central tube. By rotating the central tube forward, the central tube is driven to move to compress the rubber tube to deform, and the cone sleeve is driven to move to push the slip to open, so as to achieve the seat seal and wellbore sealing. The pressure fluid in the wellbore can only go up along the inner cavity of the central tube. When the wellbore pressure is high, the pressure sensor monitors the fluid pressure information in time, and uses the sealing structure to temporarily block it, so that the ground operators have time to perform well pressure or blowout operations, which can effectively reduce the well control risk.

Description

Technical Field

[0001] The invention relates to a downhole pressure monitoring device. Background Art

[0002] Wellhead replacement is the process of removing the original wellhead device and installing a new wellhead or Christmas tree and other components. Since different construction processes require different wellhead models, wellhead replacement is a frequently performed construction process in downhole well repair operations. For example, fracturing requires replacing a wellhead with a higher pressure, the original wellhead device needs to be replaced when it is damaged, and the oil well is converted to a water injection well and the wellhead replacement operation is indispensable.

[0003] When replacing the wellhead of an oil and gas well with energy in the formation, the wellhead is in an uncontrollable state before removal or replacement, and the pressure in the wellbore cannot be detected. When the wellbore pressure suddenly increases, a well gust or blowout accident is likely to occur. To address this problem, the current common practice is to replace the wellhead quickly and continuously, observe the changes in the wellhead liquid level at any time, and immediately initiate emergency measures once there is a sign of a blowout, forcibly install the wellhead and shut down the well.

[0004] However, this method has the following defects:

[0005] 1. After the wellhead is removed, it is in an open state and the wellbore pressure cannot be detected in time, which leads to a greater risk of well control.

[0006] 2. If the wellhead is replaced after well killing, the killing fluid is likely to contaminate the oil layer. At the same time, the increased formation pressure will also cause overflow risks, and it is still impossible to monitor the pressure conditions in the wellbore. Summary of the invention

[0007] The purpose of the present invention is to provide a downhole pressure monitoring device to solve the technical problem in the prior art that the wellbore pressure cannot be detected when changing the wellhead, resulting in a greater well control risk.

[0008] To achieve the above-mentioned purpose, the technical solution of the downhole pressure monitoring device provided by the present invention is: a downhole pressure monitoring device, comprising:

[0009] An outer pipe extending in the up-down direction and used to be sent into the wellbore by a corresponding running tool to form a wellbore annulus;

[0010] The central tube extends in the up-down direction, is located in the outer tube and is assembled with the outer tube in a spiral transmission manner, an operating part is provided on the upper part of the central tube for connecting an operating tool so as to be driven and rotated by an operator, and a plugging structure is fixed in the central tube;

[0011] The slip sealing structure includes a slip base, a cone sleeve and a rubber sleeve. The slip base is fixedly assembled with the outer pipe, a slip is arranged on the slip base, the center pipe passes through the slip base, the cone sleeve and the rubber sleeve are sleeved outside the center pipe, the cone sleeve is used to move and push the slip to open to realize the sealing, and the rubber sleeve is used to seal the wellbore annulus when deformed by pressure;

[0012] The central tube has a positive rotation stroke during its rotation. When the central tube rotates positively, it moves relative to the outer tube in the up-down direction to compress the rubber tube to deform, thereby driving the cone sleeve to move in the direction of the push slip opening;

[0013] A pressure sensor is used to monitor the fluid pressure in the central pipe. The pressure sensor includes an alarm or an alarm signal output end or a pressure signal output end. The alarm signal output end is used to send an alarm message to the alarm arranged at the wellhead. The pressure signal output end is used to output pressure information to a signal receiver arranged at the wellhead.

[0014] The beneficial effect is that in the downhole pressure monitoring device provided by the present invention, the spiral transmission in the outer tube is equipped with a central tube. When the outer tube is sent into the wellbore, the central tube is rotated forward and the spiral transmission assembly is used to drive the central tube to move to compress the rubber tube to deform, drive the cone sleeve to move to push the slip open, and realize the seat seal, so that the outer tube can be fixed in the wellbore. At the same time, the rubber tube is used to achieve the wellbore sealing. The pressure fluid in the wellbore can only go up along the inner cavity of the central tube. In this way, when the wellbore pressure is high, the pressure sensor can monitor the fluid pressure information in time. At the same time, the plugging structure can be used for temporary blocking, which is convenient for ground operators to have time to perform well pressure or blowout operations, which can effectively reduce the risk of well control.

[0015] As a further improvement, the central tube and the outer tube form an annular cavity, the central tube is provided with a flow hole, the flow hole is located below the blocking structure, the flow hole connects the inner cavity of the central tube and the annular cavity, the pressure sensor is arranged on the outer tube, and is used to monitor the fluid pressure in the central tube by measuring the fluid pressure in the annular cavity.

[0016] The beneficial effect is that the pressure sensor is arranged on the outer tube, and the pressure of the fluid in the corresponding annular cavity is measured to monitor the pressure of the fluid in the annular cavity. The pressure sensor is easy to install and the monitoring is convenient.

[0017] As a further improvement, the center tube includes an upper center tube body, an adjustment tube section and a lower center tube body which are detachably fixedly assembled together from top to bottom, the adjustment tube section is assembled with the outer tube in a spiral transmission, the upper center tube body is provided with the sealing structure, and the lower center tube body is fixedly provided with a rubber cylinder seat, and the rubber cylinder seat is used to move with the lower tube body when the center tube rotates forward to compress the rubber cylinder to deform.

[0018] The beneficial effect is that the upper central pipe body, the adjusting pipe section and the lower central pipe body can be disassembled and fixedly assembled in sequence, so that the adjusting pipe section can be selected according to actual needs.

[0019] As a further improvement, the lower end of the upper central tube body and the upper end of the lower central tube body are both inserted into the adjusting tube section.

[0020] The beneficial effect is that the lower end of the upper central tube body and the upper end of the lower central tube body are both installed in the adjusting tube section, which facilitates the spiral transmission assembly of the adjusting tube section and the outer tube and facilitates processing and manufacturing.

[0021] As a further improvement, when the central tube rotates in the forward direction to move upward relative to the outer tube, a stop step is provided on the inner side of the outer tube or the inner side of the cava base, and the step surface of the stop step is arranged upward for cooperating with the adjusting pipe section to limit the extreme position of the downward movement of the central tube.

[0022] The beneficial effect is that the stopping step arranged on the inner side of the outer tube or the slip base can effectively limit the downward movement position of the central tube.

[0023] As a further improvement, the sealing structure is a sealing cap, which is welded and fixed in the upper central tube body.

[0024] The beneficial effect is that the sealing cap is welded and fixed, which facilitates the design of the pressure that the temporary seal can withstand.

[0025] As a further improvement, the upper central tube body has an upper end that passes through the outer tube upward, and the operating part is fixedly arranged on the upper end of the upper central tube body.

[0026] The beneficial effect is that the operating part is arranged at the upper end of the upper central tube body passing through the outer tube, so that the rotation operation is convenient.

[0027] As a further improvement, when the center tube rotates in the forward direction to move upward relative to the outer tube, the lower center tube body has a lower passing section that passes downward through the cava base, the cone sleeve and the rubber cylinder are both mounted on the lower passing section, and the rubber cylinder seat is fixed on the lower passing section.

[0028] The beneficial effect is that a rubber cylinder seat is fixedly provided on the lower passing section, and the cone sleeve and the rubber cylinder are both sleeved on the lower passing section, so that the rubber cylinder is conveniently driven to deform through the rubber cylinder seat and the cone sleeve is forced to move and push the slip to open.

[0029] As a further improvement, the outer tube includes a top tube body, a connecting sleeve, a middle tube body and an upper joint that are detachably fixed and assembled together from top to bottom. The top tube body is sealed and rotatably assembled with the upper center tube body through an upper sealing structure, the upper joint is fixedly assembled with the cava base, and the upper joint is spirally assembled with the adjusting pipe section.

[0030] The beneficial effect is that the outer tube includes a top tube body, a connecting sleeve, a middle tube body and an upper joint assembly, and each component is machined separately according to actual needs and then assembled together, which is convenient for processing and manufacturing.

[0031] As a further improvement, the lower central tube body is assembled in a sealed and movable manner with the slip base through a lower sealing structure.

[0032] The beneficial effect is that the lower center pipe body is sealed and assembled with the slip base, which reduces the length requirement of the outer pipe while ensuring effective sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of Example 1 of the downhole pressure monitoring device provided by the present invention.

[0034] Description of reference numerals:

[0035] 1. Lower joint; 2. Rubber cylinder; 3. Leather cup cap; 4. Conical sleeve; 5. Slip; 6. Lower tube body; 7. Slip base; 8. Adjusting pipe section; 9. Upper joint; 10. Upper connecting pipe section; 11. Upper tube body; 12. Pressure sensor; 13. Flow hole; 14. Middle tube body; 15. Upper sealing structure; 16. Sealing cap; 17. Adjusting hole; 18. Rubber cylinder seat; 19. Lower sealing structure; 20. Annular cavity; 21. Connecting sleeve; 22. Top tube body; 100. Lower center tube body; 200. Upper center tube body; 300. Outer tube. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0038] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a..." do not exclude the process or method that includes the elements.

[0039] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" that may appear should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "provided with" that may appear should be understood in a broad sense. For example, the object "provided with" may be a part of the body, or may be arranged separately from the body and connected to the body, and the connection may be a detachable connection or an inseparable connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The present invention is further described in detail below in conjunction with embodiments.

[0042] Specific embodiment 1 of the downhole pressure monitoring device provided by the present invention:

[0043] When in use, the downhole pressure monitoring device provided in this embodiment can be lowered into the well, sealed in the wellbore, and the wellbore annulus is blocked. A corresponding pressure sensor is configured to detect the fluid pressure inside the wellbore. When the fluid pressure inside the wellbore rises to a set dangerous value, the corresponding blocking structure can be used to temporarily block it to form a protection. At the same time, the pressure sensor can transmit the corresponding information to the well, which is convenient for the operator to perform well killing or blowout operations in a timely manner according to actual needs, thereby ensuring the safety performance of well control.

[0044] like Figure 1As shown, the downhole pressure monitoring device in this embodiment as a whole includes an outer tube 300, a center tube and a cava seal structure. The center tube as a whole includes an upper center tube body 200, an adjusting tube section 8 and a lower center tube body 100 that are connected. The upper center tube body 200 and the lower center tube body 100 are arranged in the outer tube 300 respectively. The cava seal structure is arranged on the lower center tube body 100 and the outer tube 300, and is used for sealing and fixing in the wellbore.

[0045] The outer tube 300 extends in the up-down direction as a whole, and is used to be sent into the wellbore by a corresponding delivery tool to form a wellbore annulus. The delivery tool can be a tubing elevator. The outer tube 300 specifically includes a top tube body 22, a connecting sleeve 21, a middle tube body 14 and an upper joint 9 arranged in sequence from top to bottom. Here, the top tube body 22, the connecting sleeve 21, the middle tube body 14 and the upper joint 9 are all sleeve structures. The upper and lower ends of the connecting sleeve 21 are correspondingly threadedly fixedly connected to the top tube body 22 and the middle tube body 14, and the lower end of the middle tube body 14 is threadedly fixedly connected to the upper joint 9.

[0046] The upper central tube body 200 specifically includes an upper tube body 11 and an upper connecting tube section 10 which are separately fixedly assembled together. The upper connecting tube section 10 is welded to the lower end of the upper tube body 11, and the upper connecting tube section 10 is also a sleeve structure. An upper sealing structure 15 is provided on the inner circumference of the upper end of the top tube body 22, specifically including an upper sealing ring, and the top tube body 22 is sealed and rotatably assembled with the upper tube body 11 through the upper sealing structure 15.

[0047] In addition, the upper tube body 11 has an upper end that passes through the top tube body 22 upward, and an operating part is provided at the upper end of the upper tube body 11. The operating part here is specifically two through-holes 17 for connecting an operating tool so that the operator can drive the upper center tube body 200 to rotate.

[0048] In addition, a sealing structure is fixed in the inner cavity at the upper part of the upper tube body 11. The sealing structure here is specifically a sealing cap 16. The sealing cap 16 is welded and fixed in the upper tube body 11 to effectively seal the upper central tube body 200 until the set pressure value is reached, at which time the sealing cap 16 will be destroyed and opened.

[0049] The inner cavity of the upper pipe body 11 is connected with the inner cavity of the lower central pipe body 100, and the upper pipe body 11 and the middle pipe body 14 form an annular cavity 20, and a through hole 13 is provided on the upper pipe body 11, and the through hole 13 connects the inner cavity of the upper pipe body 11 and the above-mentioned annular cavity 20. A pressure sensor 12 is fixedly installed on the upper pipe body 11, which can measure the fluid pressure in the annular cavity 20. Since the inner cavity of the lower central pipe body 100 is connected with the annular cavity 20 through the inner cavity of the upper pipe body 11, the pressure sensor 12 can monitor the fluid pressure in the lower central pipe body 100 by measuring the fluid pressure in the annular cavity 20, thereby realizing effective detection of the wellbore pressure.

[0050] The through holes 13 on the upper tube body 11 are arranged in a plurality of rows along the circumferential direction, and each row has four through holes 13 arranged in sequence along the vertical direction. During the specific manufacturing process, the number and position of the through holes 13 can be arranged according to actual needs.

[0051] In this embodiment, the upper central tube body includes an upper tube body and an upper connecting tube section, and the lower central tube body 100 mainly includes a lower tube body 6. The adjusting tube section 8 is assembled with the upper joint 9 by spiral transmission. The inner circumference of the upper joint 9 is provided with an inner left-handed trapezoidal thread, and the outer circumference of the adjusting tube section 8 is provided with a corresponding outer left-handed trapezoidal thread to cooperate with the inner left-handed trapezoidal thread to form a screw nut structure. When the outer tube is fixed, the central tube can be rotated to make the central tube move up and down relative to the outer tube. The adjusting tube section 8 is threadedly fixedly assembled with the upper connecting tube section 10 and the lower central tube body 100, and the lower end of the upper connecting tube section 10 and the upper end of the lower tube body 6 are both inserted into the adjusting tube section 8, so as to facilitate the spiral transmission assembly of the adjusting tube section 8 and the upper joint 9. In this way, when the operator rotates the central tube at the wellhead, the central tube can be lifted and lowered relative to the outer tube. In this embodiment, when the upper central tube body 200 rotates forward, the central tube can move upward relative to the outer tube, and when the upper central tube body 200 rotates reversely, the central tube can move downward relative to the outer tube.

[0052] The slip seat seal structure specifically includes a slip base 7, a cone sleeve 4, a leather cup cap 3, a rubber cylinder 2 and a rubber cylinder seat 18. The upper end of the slip base 7 is threadedly fixedly connected to the lower end of the upper joint 9 so that the slip base 7 is fixedly assembled with the outer tube 300. Six slips 5 are arranged on the slip base 7. The lower central tube body 100 passes through the slip base 7 and passes through the slip base 7 downward. The part of the lower central tube body 100 that passes through the slip base 7 downward is the lower passing section. The cone sleeve 4, the leather cup cap 3, the rubber cylinder 2 and the rubber cylinder seat 18 are sequentially mounted on the lower passing section from top to bottom, and the rubber cylinder seat 18 is fixedly assembled with the lower passing section.

[0053] The slip sealing structure provided in this embodiment is the same as the slip sealing structure commonly used in the prior art. The conical sleeve 4 is used to push the slip 5 to open so as to realize the sealing of the slip 5. The rubber cylinder 2 expands and deforms when under pressure to seal the wellbore annulus.

[0054] In this embodiment, if Figure 1 As shown, when the upper center tube body 200 rotates forward and drives the center tube to move upward, the rubber tube seat 18 pushes the rubber tube 2 upward, and at the same time, the leather cup cap 3 pushes the cone sleeve 4 upward. The rubber tube seat 18 pushes the rubber tube 2 to compress the rubber tube 2 to deform, and pushes the cone sleeve 4 upward through the rubber tube 2 to drive the cava 5 to open.

[0055] In addition, in this embodiment, a lower joint 1 is connected to the lower end of the lower central pipe body 100. If a lower wellbore pipe string needs to be connected, the lower joint 1 can be used to fix the lower pipe string.

[0056] In this embodiment, a stop step is provided on the inner side of the cava base 7, and the step surface of the stop step is arranged upward. When the cava base 7 is threadedly matched with the upper joint 9, the stop step is matched with the lower end of the upper joint 9. At the same time, the stop step is also used to match with the lower end of the adjusting pipe section 8 to limit the entire center pipe from moving downward to the extreme position.

[0057] In consideration of convenient assembly, the annular cavity 20 formed by the outer tube 300 and the upper center tube body 200 relies on the cooperation of the above-mentioned upper sealing structure 15 and the corresponding lower sealing structure 19 to form an effective seal. The lower sealing structure 19 is specifically installed on the inner side of the cava base 7 facing the lower tube body 6. The lower sealing structure 19 specifically includes a lower sealing ring, which is located below the vertical guide structure and the adjusting pipe section 8 in the up and down directions, and forms a movable sealing fit with the lower tube body 6.

[0058] Combination Figure 1 , the use process of this device is as follows:

[0059] Before starting the wellhead replacement construction, use a tubing elevator to hit the middle pipe body 14, lower the downhole pressure monitoring device into the wellbore through the operating machine, and then use a round rod to pass through the adjusting hole 17. The positive rotation of the round rod drives the upper pipe body 11 to rotate forward, and the upper pipe body 11 drives the upper connecting pipe section 10 to rotate forward, and at the same time drives the adjusting pipe section 8 and the lower center pipe body to rotate forward. Since the outer pipe is fixed by the tubing elevator, the center pipe can move upward to the outer pipe first, and the rubber cylinder 2, the leather cup cap 3 and the cone sleeve 4 are pushed upward through the rubber cylinder seat 18, forcing the slip 5 to support the seat seal, and the rubber cylinder 2 is compressed and deformed to seal the wellbore annulus, so that the entire wellbore annulus is in a sealed state.

[0060] Since the lower center pipe body 100 and the upper center pipe body 200 are connected, the fluid at the inner end of the lower center pipe will enter the annular cavity 20 of the upper pipe body 11 and the outer pipe 300 through the flow hole 13 on the upper pipe body 11 and be detected by the pressure sensor 12. The pressure signal output end of the pressure sensor 12 is used to output pressure information to a signal receiver arranged at the wellhead, such as a pressure digital display, so that the pressure in the wellbore can be monitored in real time on the ground.

[0061] When the pressure reaches the set dangerous value, the sealing cap 16 in the upper pipe body 11 can be temporarily blocked to gain operation time, making it convenient for ground operators to perform well killing or blowout according to actual conditions, so that the pressure in the wellbore can be released and the entire wellhead replacement process can be kept under control.

[0062] In addition, when the danger is eliminated and the downhole monitoring device needs to be dismantled, the upper central tube body 200 can be rotated in the opposite direction. At this time, the central tube moves downward accordingly, and the rubber cylinder 2 resets itself. At this time, the slip 5 also retracts under the action of the corresponding elastic member, and then the tool can be lowered to salvage the entire monitoring device.

[0063] The downhole pressure monitoring device provided in this embodiment is lowered into the wellbore when changing the wellhead, and can effectively monitor the fluid pressure in the wellbore. When the pressure rises to a dangerous value, since the wellbore annulus is temporarily blocked, the inner cavity of the upper center pipe is also temporarily blocked, which can save operation time and facilitate operators to take timely response measures, effectively reducing the well control risk during the wellhead replacement construction, so that the entire process is in a controllable state. In addition, the device is light in weight, small in size, and simple to operate, which greatly reduces the labor intensity.

[0064] Specific embodiment 2 of the downhole pressure monitoring device provided by the present invention:

[0065] The main difference between it and Example 1 is that in Example 1, the pressure sensor is installed on the middle tube body to detect the fluid pressure in the annular cavity formed by the upper tube body and the middle tube body, that is, the annular cavity formed by the upper center tube body and the outer tube, and the flow hole of the upper tube body is used to detect the fluid pressure in the lower center tube body. In this embodiment, the pressure sensor can be set on the upper part of the upper tube body, that is, above the outer tube, but below the sealing cap, and the pressure sensor directly detects the fluid pressure in the upper tube body, so that the fluid pressure in the lower center tube can be detected.

[0066] Specific embodiment 3 of the downhole pressure monitoring device provided by the present invention:

[0067] The main difference between it and Example 1 is that in Example 1, the pressure sensor is installed on the middle tube body to detect the fluid pressure in the annular cavity formed by the upper tube body and the middle tube body, that is, the annular cavity formed by the upper center tube body and the outer tube, and the flow hole of the upper tube body is used to detect the fluid pressure in the lower center tube body. In this embodiment, the pressure sensor can be set on the lower joint, and since the lower joint is connected to the lower center tube, the fluid pressure in the lower center tube can also be monitored.

[0068] Specific embodiment 4 of the downhole pressure monitoring device provided by the present invention:

[0069] The main difference between it and Example 1 is that in Example 1, the upper central tube body includes an upper tube body and an upper connecting tube section which are assembled separately, and the processing and manufacturing is relatively convenient. In this embodiment, the central tube directly adopts an integrated structure, and the corresponding spiral transmission structure is directly processed on the outer circumference of the central tube to ensure the spiral transmission assembly of the central tube and the outer tube.

[0070] Specific embodiment 5 of the downhole pressure monitoring device provided by the present invention:

[0071] The main difference between it and Example 1 is that in Example 1, the outer tube includes a top tube body, a top tube body, a connecting sleeve, a middle tube body and an upper joint which are assembled separately, and it is also convenient to process and manufacture. In this embodiment, the outer tube is an integrated structure, and an upper sealing ring is assembled on the inner circumference of the upper end to form an upper sealing structure, and a corresponding spiral transmission structure is arranged at the lower part to be assembled with the central tube spiral transmission, and is threadedly fixedly connected with the slip base.

[0072] Specific embodiment 6 of the downhole pressure monitoring device provided by the present invention:

[0073] The main difference between this embodiment and the first embodiment is that in the first embodiment, the sealing structure on the upper part of the upper central tube body adopts a sealing cap assembled by welding. In this embodiment, the sealing structure on the upper part of the upper central tube body can also be a plug welded at the top opening of the upper central tube body. In this case, the operating part on the upper part of the upper central tube body can be designed on the outside of the upper central tube body, for example, a radial adjustment rod is arranged on the outside of the upper central tube body, and the corresponding operating cylinder is connected to the radial adjustment rod, so that the upper central tube body can be driven to rotate forward and reverse through the radial adjustment rod.

[0074] Specific embodiment 7 of the downhole pressure monitoring device provided by the present invention:

[0075] The main difference between it and Example 1 is that: in Example 1, the cone sleeve is located below the slip base. At this time, the middle tube body is fixed, and the upper center tube body is rotated forward. Under the action of the upper joint and the adjusting pipe section, the lower center tube body is driven upward, so that the slip seat seal and the rubber cylinder deformation can be achieved. In this embodiment, the slip base can be fixedly installed on the upper joint, and the rubber cylinder, the cone sleeve and the slip base are correspondingly mounted on the lower center tube body from bottom to top. At this time, the cone sleeve needs to move upward to drive the slip to open and achieve the seat seal. Correspondingly, when the upper center tube body rotates in the opposite direction, it is necessary to design to ensure that the lower center tube body moves downward to achieve normal sealing and seat seal.

[0076] Specific embodiment 8 of the downhole pressure monitoring device provided by the present invention:

[0077] The main difference between the embodiment 1 and the embodiment 1 is that in the embodiment 1, the pressure sensor includes a pressure signal output end, which is used to output pressure information to a signal receiver arranged at the wellhead. In this embodiment, the pressure sensor may include an alarm signal output end, which is used to send an alarm message to an alarm arranged at the wellhead. When the pressure sensor detects that the fluid pressure in the central pipe rises to a set pressure value, the alarm signal output end sends information to the alarm, and the alarm sounds an alarm.

[0078] Of course, in other implementations, the pressure sensor on the outer tube may directly include an alarm. When the pressure sensor detects that the downhole pressure rises to a set pressure value, an alarm is directly sounded downhole. At this time, the operator needs to pay attention to the downhole alarm sound.

[0079] Specific embodiment 9 of the downhole pressure monitoring device provided by the present invention:

[0080] The main difference between this embodiment and the first embodiment is that: in the first embodiment, a stop step is provided on the inner side of the slip base, and the step surface of the stop step is arranged upward, and is used to cooperate with the stop of the adjusting pipe section to limit the extreme position of the downward movement of the central pipe. In this embodiment, a stop step can also be provided on the inner side of the outer pipe, and can also cooperate with the stop of the adjusting pipe section to limit the extreme position of the downward movement of the central pipe.

[0081] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A downhole pressure monitoring device, characterized in that: include: An outer pipe extending in the up-down direction and used to be sent into the wellbore by a corresponding running tool to form a wellbore annulus; The central tube extends in the up-down direction, is located in the outer tube and is screw-drivenly assembled with the outer tube, an operating part is provided on the upper part of the central tube, which is used to connect the operating tool so as to be driven and rotated by the operator, a plugging structure is fixedly provided in the central tube, and the central tube includes an upper central tube body, an adjusting tube section and a lower central tube body which are detachably fixedly assembled together from top to bottom, the adjusting tube section is screw-drivenly assembled with the outer tube, and a rubber cylinder seat is fixedly provided on the lower central tube body; The slip sealing structure includes a slip base, a cone sleeve and a rubber sleeve. The slip base is fixedly assembled with the outer pipe, a slip is arranged on the slip base, the center pipe passes through the slip base, the cone sleeve and the rubber sleeve are sleeved outside the center pipe, the cone sleeve is used to move and push the slip to open to realize the sealing, and the rubber sleeve is used to seal the wellbore annulus when deformed by pressure; The central tube has a positive rotation stroke during its rotation. When the central tube rotates positively, it moves relative to the outer tube along the central tube axis direction. The rubber tube seat moves with the lower tube body to compress the rubber tube to deform, thereby driving the cone sleeve to move in the direction of the push slip opening. A pressure sensor is used to monitor the fluid pressure in the central pipe. The pressure sensor includes an alarm or an alarm signal output end or a pressure signal output end. The alarm signal output end is used to send an alarm message to the alarm arranged at the wellhead. The pressure signal output end is used to output pressure information to a signal receiver arranged at the wellhead.

2. The downhole pressure monitoring device according to claim 1, characterized in that: The central tube and the outer tube form an annular cavity. The central tube is provided with a flow hole, which is located below the blocking structure. The flow hole connects the inner cavity of the central tube and the annular cavity. The pressure sensor is arranged on the outer tube and is used to monitor the fluid pressure in the central tube by measuring the fluid pressure in the annular cavity.

3. The downhole pressure monitoring device according to claim 1, characterized in that: The lower end of the upper central tube body and the upper end of the lower central tube body are both installed in the adjusting tube section.

4. The downhole pressure monitoring device according to claim 3, characterized in that: When the central tube rotates in the positive direction to move upward relative to the outer tube, a stop step is provided on the inner side of the outer tube or the inner side of the slip base, and the step surface of the stop step is arranged upward for cooperating with the adjusting pipe section to limit the extreme position of the downward movement of the central tube.

5. The downhole pressure monitoring device according to claim 1, characterized in that: The blocking structure is a sealing cap, which is welded and fixed in the upper central tube body.

6. The downhole pressure monitoring device according to claim 5, characterized in that: The upper central tube body has an upper end that passes through the outer tube upwards, and the operating part is fixedly arranged on the upper end of the upper central tube body.

7. The downhole pressure monitoring device according to claim 1, characterized in that: When the center tube rotates in the forward direction to move upward relative to the outer tube, the lower center tube body has a lower passing section passing downward through the slip base, the cone sleeve and the rubber cylinder are both sleeved on the lower passing section, and the rubber cylinder seat is fixedly provided on the lower passing section.

8. The downhole pressure monitoring device according to claim 1, characterized in that: The outer tube includes a top tube body, a connecting sleeve, a middle tube body and an upper joint which are detachably fixedly assembled together from top to bottom. The top tube body is sealingly and rotatably assembled with the upper center tube body through an upper sealing structure, the upper joint is fixedly assembled with the slip base, and the upper joint is spirally assembled with the adjusting pipe section.

9. The downhole pressure monitoring device according to claim 8, characterized in that: The lower central tube body is assembled and sealed with the slip base through a lower sealing structure.

Images