Oil extraction wellhead device with remote monitoring function and control system thereof

Abstract

The invention provides an oil extraction wellhead device with a remote monitoring function and a control system thereof, and relates to the technical field of oil exploitation, the oil extraction wellhead device with the remote monitoring function comprises a casing head, a slip part and a bolt, the outer side of the bolt is jointly provided with an annular and flexible synchronizing part, the size of the synchronizing part in the track direction of the synchronizing part is constant, and the size of the slip part is smaller than that of the sleeve head. After one bolt is rotated, the sunken degrees of the sunken sections on the two sides of the bolt are increased and decreased correspondingly, and the sunken degrees of all the sunken sections are restored when all the bolts are screwed. The sunken degree of the sunken section is used for assisting manual judgment of the single-time rotation amount of the bolt, when the bolt reaches the single-time rotation amount, the bolt cannot continue to rotate, the manual single-time rotation amount is reminded and limited, the accumulated rotation amount of each bolt is basically consistent, the slip part is evenly stressed, deflection of the slip part and the axis of the inner sleeve is avoided, and the service life of the inner sleeve is prolonged. And meanwhile, the screwing process of the bolt is simple, the operation is easy, and the consistency and the fineness of the operation are ensured.

Description

Technical Field

[0001] This invention relates to the field of oil extraction technology, and in particular to an oil wellhead device with remote monitoring function and its control system. Background Technology

[0002] In the oil extraction industry, the Christmas tree is a core equipment assembly installed at the wellhead, playing a crucial role in controlling and regulating the production process of both flowing and mechanically operated wells. A typical Christmas tree system includes the Christmas tree body, the tubing head, and the casing head at the bottom. As the base of the entire wellhead assembly, the casing head serves as a connection and transition: its lower end connects to the casing string at various underground levels, while its upper end supports the tubing head and the Christmas tree body. During drilling and completion operations, the casing head is used to suspend the casing, bear the weight of the blowout preventer or Christmas tree, provide interfaces for annular pressure monitoring and cementing, and is fundamental to ensuring wellbore integrity and production safety. Currently, common casing heads employ a slip-type mechanical fixing structure, combined with BT sealing rings and injection molding systems to achieve high-pressure sealing, with working pressures up to 70 MPa, suitable for acidic environments and low-temperature conditions. Its installation process must strictly adhere to standard procedures such as wellhead alignment, flange level control, and sealing system pressure testing to ensure the stability and safety of the wellhead assembly.

[0003] In the WD-type slip fixing structure, the outer slip is connected and fixed to the sleeve head by multiple bolts evenly distributed around the circumference. During operation, each bolt must be tightened in small amounts and multiple times, and the cumulative rotation of each bolt must be basically consistent to ensure that the slip is evenly stressed, avoiding misalignment between the inner and outer slips and the sleeve axis, or even jamming. The above operation process is quite cumbersome, and manual operation is difficult to guarantee consistency and precision.

[0004] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] Therefore, it is necessary to provide an oil wellhead device and its control system with remote monitoring function to address the problems existing in current oil wellhead devices.

[0006] The above objectives are achieved through the following technical solutions:

[0007] An oil wellhead device with remote monitoring function includes a tree and a casing head connected to its lower end. A central hole is drilled vertically through the casing head, and an inner casing is coaxially inserted into the central hole. A slip portion is provided on the casing head, and bolts are inserted axially along the central hole on the slip portion. Multiple bolts are evenly spaced along the circumference of the central hole and are threaded to the casing head to fix the inner casing to the casing head. A ring-shaped, flexible synchronizing element is provided on the outer side of all bolts. The synchronizing element has a constant dimension in its trajectory direction. A tensioning wheel is provided on the casing head between two adjacent bolts. The tensioning wheel contacts the outer side of the synchronizing element, causing the synchronizing element to be tensioned. The contacted position of the synchronizing element forms a recessed section towards the axis of the central hole. The tensioning wheel and the casing... The head is movable to allow the tensioning wheel to adapt to changes in the degree of concavity in the recessed sections. A one-way gear ring, coaxial with the center hole, is rotatably mounted on the slip portion. The outer side of the one-way gear ring abuts against the inner side of all bolts. The one-way gear ring allows the bolts to rotate in a first direction but restricts their rotation in a second direction. The bolts tighten when rotating in the first direction and loosen when rotating in the second direction. When one bolt is rotated in the first direction by a first external force, the one-way gear ring and the other bolts remain stationary. Before rotation, the degree of concavity in all recessed sections is a first preset value. After rotation, the degree of concavity in the recessed sections on both sides of the bolt increases and decreases relative to the first preset value, respectively. When all bolts are tightened, the degree of concavity in all recessed sections is the first preset value.

[0008] Furthermore, before one of the bolts is rotated by the first external force, the one-way gear ring is rotated by the second external force, causing all the bolts to rotate in the first direction to pre-tighten all the bolts. The first external force is greater than the second external force.

[0009] Furthermore, a support rod is rotatably provided on the sleeve head, and the tensioning wheel is rotatably connected to the lower end of the support rod. The rotation axis of the support rod is perpendicular to the first plane, which passes through the axial and radial directions of the central hole, so that the tensioning wheel can swing with the support rod on the first plane. An elastic element is provided between the support rod and the sleeve head, which makes the tensioning wheel touch the outside of the synchronizing element or tend to touch the outside of the synchronizing element.

[0010] Furthermore, a through hole is provided on the slip part along the axial direction of the central hole, and the bolt is inserted into the through hole with clearance fit between the two; before the one-way gear ring is rotated by the second external force, the distance between the support rod and the axis of the central hole gradually decreases from bottom to top, so that the length direction of the support rod forms a first angle with the axis of the central hole. When the one-way gear ring is rotated by the second external force, the first angle increases, and the elastic element makes the inner side of all bolts fully abut against the outer side of the one-way gear ring.

[0011] Furthermore, the slip assembly includes an inner slip and an outer slip. The inner slip is coaxially fitted onto the inner sleeve, and the inner wall of the inner slip is provided with an obstruction. The obstruction allows the inner sleeve to move upward along the inner slip, while restricting the inner sleeve from moving downward along the inner slip. A limiting element is provided in the central hole to limit the distance the inner sleeve moves upward. A through hole is opened on the outer slip, and the outer slip is fitted onto the inner slip. Both the inner wall of the outer slip and the outer wall of the inner slip are provided with conical surfaces that can contact each other. The distance between the conical surfaces and the axis of the central hole gradually increases from bottom to top.

[0012] Furthermore, the bolt has a first annular groove along its circumference, the synchronizing element is located in the first annular groove, and a contact element is provided in the first annular groove to increase the static friction between the synchronizing element and the first annular groove; the bolt has a second annular groove along its circumference, and the outer side of the one-way gear ring is located in the second annular groove.

[0013] Furthermore, the lower end of the sleeve head is provided with an outer sleeve, and the inner sleeve is inserted into the outer sleeve. An adjustment part is provided between the sleeve head and the outer sleeve. The adjustment part includes a first screw and a second screw, both arranged axially along the central hole. Multiple first screws and second screws are equally spaced along the circumference of the central hole. The number of first screws and second screws is equal and they are alternately arranged along the circumference of the central hole. The first screw passes through the sleeve head and is threadedly connected to the outer sleeve. The second screw is threadedly connected to the sleeve head and its end abuts against the upper end of the outer sleeve.

[0014] This invention also provides the following technical solutions:

[0015] An oil wellhead control system with remote monitoring capabilities includes:

[0016] Processors and user terminals;

[0017] A pressure sensor is installed between the elastic element and the sleeve head. The pressure sensor is used to detect the force between the elastic element and the sleeve head. When all bolts are tightened, the force between the elastic element and the sleeve head is the initial value. The processor obtains the detected value of the force between the elastic element and the sleeve head and calculates the absolute value of the difference between the detected value and the initial value.

[0018] The processor determines whether all absolute values ​​are less than a second preset value. If so, the processor sends a normal signal to the user terminal; otherwise, the processor sends a loose signal to the user terminal.

[0019] Furthermore, the number of bolts is an integer greater than or equal to 4; when the detection values ​​on both sides of a single bolt are greater than and less than the initial value, and the absolute values ​​on both sides of a single bolt are greater than or equal to the second preset value, the processor sends an interval loosening signal to the user terminal; when the detection values ​​on both sides of two or more adjacent bolts are greater than and less than the initial value, and the absolute values ​​on both sides of two or more adjacent bolts are greater than or equal to the second preset value, and the absolute value between two or more adjacent bolts is less than the second preset value, the processor sends a continuous loosening signal to the user terminal; when the detection values ​​on both sides of each bolt are less than the initial value, and the absolute values ​​on both sides of each bolt are greater than the second preset value and gradually decrease, the processor sends a complete loosening signal to the user terminal.

[0020] Furthermore, the support rod is equipped with an inclination sensor. When all bolts are tightened, the inclination sensor is used to detect the rate of change of the first included angle within a preset time. The processor determines whether the rate of change is less than a third preset value. If so, the processor sends a normal signal to the user terminal; if not, the processor sends a pre-loosening signal to the user terminal.

[0021] The present invention has at least the following beneficial effects:

[0022] (1) When one of the bolts is rotated in the first direction by the first external force, the one-way gear ring and other bolts are stationary. Before rotation, the degree of concavity of all the recessed sections is the first preset value. After rotation, the degree of concavity of the recessed sections on both sides of the bolt increases and decreases relative to the first preset value, respectively. When all the bolts are tightened, the degree of concavity of all the recessed sections returns to the first preset value. The degree of concavity of the recessed sections is used to help judge the single rotation amount of the bolt. When the bolt reaches its single rotation amount, it cannot continue to rotate, so as to remind and limit the single rotation amount of the operator. This makes the cumulative rotation amount of each bolt basically consistent, so that the clamping part is evenly stressed, avoiding the clamping part from being misaligned with the axis of the inner sleeve, or even causing jamming. At the same time, the bolt tightening process is simple and easy to operate, which can ensure the consistency and precision of the operation.

[0023] (2) The processor detects the force between the elastic element and the sleeve head by the pressure sensor. The processor determines whether the absolute value of the difference between all detected values ​​and the initial value is less than the second preset value. If so, the processor sends a normal signal to the user terminal. If not, it means that there is a certain detected value whose absolute value is greater than or equal to the second preset value, that is, there is a loose bolt. The processor sends a loose signal to the user terminal to prompt the user to tighten the loose bolt in time, thereby realizing remote real-time monitoring of the bolt, timely detection of the loosening of the slip, and intervention. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the structure of an oil wellhead device with remote monitoring function provided in an embodiment of the present invention;

[0025] Figure 2 for Figure 1 Exploded view of the parts;

[0026] Figure 3 This is an exploded view of the sleeve head components;

[0027] Figure 4 for Figure 3 Exploded view of a part with a local structure;

[0028] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0029] Figure 6 This is a front view of the casing head;

[0030] Figure 7 for Figure 6 BB-direction sectional view;

[0031] Figure 8 for Figure 7 A magnified view of a section at point C;

[0032] Figure 9 for Figure 7 DD section view;

[0033] Figure 10 for Figure 9 EE-directed sectional view;

[0034] Figure 11 for Figure 9 FF section view;

[0035] Figure 12 for Figure 11 Schematic diagram of the structure of the middle bolt and the synchronization component;

[0036] Figure 13 for Figure 12 A diagram showing the state of the bolt at the lower left after rotation;

[0037] Figure 14 for Figure 13 A diagram showing the state of the bolt directly below the center rotation;

[0038] Figure 15 for Figure 11 Diagram showing the state of the bolt at the bottom center when it is loose;

[0039] Figure 16 for Figure 11 Diagram showing the state of the bolts at the bottom center and top right when they are loose;

[0040] Figure 17 for Figure 11 Diagram showing the state of the bolts at the bottom center and bottom right when they are loose;

[0041] Figure 18 for Figure 11 Diagrams showing the state of the bolts when they are loose, located at the bottom center, bottom right, and top right.

[0042] Figure 19 for Figure 11 Diagram showing the state when all bolts are loose.

[0043] in:

[0044] 100. Christmas tree; 101. Casing head; 102. Center hole; 103. Inner casing; 104. Bolt; 105. Main valve; 106. Tubing head; 107. Throttler; 108. Sampling valve; 109. Wax removal valve; 110. Inner slip; 111. Outer slip; 112. Obstruction element; 113. Conical surface; 114. Injection valve; 115. Support ring; 116. Rotary drum; 117. Outer casing; 118. First screw; 119. Second screw; 120. Upper tray; 121. Lower tray;

[0045] 201. Synchronizing element; 202. Tensioning wheel; 203. One-way gear ring; 204. Support rod; 205. Elastic element; 206. First annular groove; 207. Second annular groove; 208. Pressure sensor. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0047] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] like Figures 1 to 19 As shown, this embodiment of the invention provides an oil wellhead device with remote monitoring function, including a tree 100 and a casing head 101 connected to its lower end. A central hole 102 is formed through the casing head 101 vertically. An inner casing 103 is coaxially inserted into the central hole 102. A slip portion is provided on the casing head 101, and bolts 104 are inserted axially along the central hole 102 on the slip portion. Multiple bolts 104 are evenly spaced along the circumference of the central hole 102. The bolts 104 are threadedly connected to the casing head 101 to fix the inner casing 103 onto the casing head 101. A ring-shaped and flexible synchronizing element 201 is provided on the outer side of all bolts 104. The synchronizing element 201 has a constant dimension in its trajectory direction. A tensioning wheel 202 is provided on the casing head 101 between two adjacent bolts 104. The tensioning wheel 202 contacts the outer side of the synchronizing element 201 to tension the synchronizing element 201, and the contacted position of the synchronizing element 201 is towards the central hole. A recessed section is formed along the axis of 102, and the tensioning wheel 202 is movably connected to the sleeve head 101 so that the tensioning wheel 202 can adapt to changes in the degree of recess in the recessed section. A one-way gear ring 203 coaxial with the center hole 102 is rotatably provided on the slip portion. The outer side of the one-way gear ring 203 abuts against the inner side of all bolts 104, and the one-way gear ring 203 allows the bolts 104 to rotate in the first direction while restricting the bolts 104 to rotate in the second direction. When the bolts 104 rotate in the first direction, they are tightened, and when they rotate in the second direction, they are loosened. When one of the bolts 104 is rotated in the first direction by a first external force, the one-way gear ring 203 and the other bolts 104 are stationary. Before rotation, the degree of recess in all recessed sections is a first preset value. After rotation, the degree of recess in the recessed sections on both sides of the bolt 104 increases and decreases relative to the first preset value, respectively. When all bolts 104 are tightened, the degree of recess in all recessed sections is the first preset value.

[0050] When one of the bolts 104 is rotated in the first direction by a first external force, the one-way gear ring 203 and the other bolts 104 remain stationary. Before rotation, the degree of concavity of all recessed sections is at a first preset value. After rotation, the degree of concavity of the recessed sections on both sides of the bolt 104 increases and decreases relative to the first preset value, respectively. When all bolts 104 are tightened, the degree of concavity of all recessed sections returns to the first preset value. The degree of concavity of the recessed sections helps to manually judge the single rotation amount of the bolt 104. When the bolt 104 reaches its single rotation amount, it cannot continue to rotate, thus reminding and limiting the single rotation amount for the operator. This ensures that the cumulative rotation amount of each bolt 104 is basically consistent, so that the clamping part is evenly stressed, avoiding misalignment between the clamping part and the axis of the inner sleeve 103, or even jamming. At the same time, the tightening process of the bolts 104 is simple and easy to operate, ensuring consistency and precision in operation.

[0051] The existing wellhead 100 includes a main valve 105, tubing head 106, production valve, throttle valve 107, sampling valve 108, dewaxing valve 109, pressure gauge, etc. Its function is to control and regulate the production of the flowing well and guide the oil and gas ejected from the well into the production pipeline. The main valve 105 is the primary channel for controlling the flow of oil and gas into the Christmas tree 100, and it is opened during production. The tubing head 106 is connected to the dewaxing valve 109 and the main valve 105 at the top and bottom, respectively, and to the production valves on both sides. It serves as both a connecting component and a channel for the flow of oil and gas and the insertion of instruments into the well. The production valve controls the flow of oil and gas to the production line and is opened during production. The throttle valve 107 (also known as a throttle valve or nozzle sleeve) controls the production pressure differential of the oil layer and regulates the well production during production. The sampling valve 108 is used for sampling or inspection and for venting when changing the lubrication circuit. The dewaxing valve 109 is installed at the top of the Christmas tree 100 and can be connected to the blowout preventer for dewaxing or well testing. The dewaxing valve 109 is opened when dewaxing or inserting testing instruments into the well. The pressure gauge is used to observe and obtain the tubing pressure.

[0052] The synchronizing element 201 is preferably a ring-shaped steel wire rope with a constant dimension in its trajectory direction, but can deform in other directions. In other embodiments not shown, the synchronizing element 201 can also be a conveyor belt structure with toothed grooves on its inner wall. Correspondingly, the outer side of the bolt 104 is provided with a toothed ring that meshes with the toothed grooves along its circumference.

[0053] Additionally, the tensioning wheel 202 has a groove along its circumference, and the synchronizing element 201 is correspondingly engaged within the groove. All bolts 104 are located inside the synchronizing element 201, and the bolts 104 abut against the inner side of the synchronizing element 201 from the inside out. The tensioning wheel 202 is located outside the synchronizing element 201, and the tensioning wheel 202 abuts against the outer side of the synchronizing element 201 from the outside in. Bolts 104 and tensioning wheels 202 are alternately arranged along the circumference of the central hole 102; in other words, a tensioning wheel 202 is positioned between two adjacent bolts 104, and a bolt 104 is positioned between two adjacent tensioning wheels 202. Therefore, the number of bolts 104 and tensioning wheels 202 is equal. A first external force can be generated using existing power tools to rotate the bolts 104.

[0054] It is understandable that before one of the bolts 104 is rotated in the first direction by the first external force, the degree of concavity of the recessed sections on both sides of the bolt 104 is the same, both being a first preset value. For ease of description, this degree of concavity can be referred to as "concave". After one of the bolts 104 is rotated in the first direction by the first external force, the degree of concavity of the recessed sections on both sides of the bolt 104 increases and decreases relative to the first preset value, respectively. Similarly, these two degrees of concavity can be referred to as "flat" and "over-concave" respectively. Therefore, from "over-concave" to "concave" and then to "flat", the degree of concavity of the recessed section gradually decreases. For example, Figure 12 Before all bolts 104 are rotated by the first external force, the concave sections on both sides of each bolt 104 have the same degree of concavity, both being "concave". Rotating the lower left bolt 104 changes its upper concave section from "concave" to "over-concave", and its lower concave section from "concave" to "flat", as shown below. Figure 13 Rotate all bolts 104 sequentially in the second direction, then rotate the bottommost bolt 104 so that its left concave section changes from "flat" to "concave," and its right concave section changes from "concave" to "flat," as shown. Figure 14Additionally, the operator can determine the extent of rotation of the bolt 104 by observing whether the concave sections on both sides of the rotating bolt 104 change from "flat" to "concave" (or from "concave" to "over-concave"), or from "concave" to "flat." In other words, once the change from "concave" to "flat" occurs, it can be determined that the bolt 104 has reached its single rotation range. If the operator continues to rotate the bolt 104 at this point, the first external force needs to be applied many times more under the action of the synchronizing element 201 and the adjacent bolts 104, thus preventing further rotation of the bolt 104. This serves as a reminder and limitation for the operator's single rotation. The amount of rotation is adjusted so that the cumulative rotation of each bolt 104 is basically consistent. This process is repeated, rotating all bolts 104 sequentially, i.e., rotating them counter-clockwise, so that the "flat" position also moves counter-clockwise. When the bolt 104 in the upper left corner is rotated, its upper concave section changes from "flat" to "concave," and its lower concave section changes from "over-concave" to "concave." Therefore, in the first cycle, after rotating all bolts 104, the degree of concavity of all concave sections returns to the first preset value. This state can also be seen in [reference needed]. Figure 12 This process is repeated multiple times, rotating all bolts 104 until they can no longer be rotated. The final tightened state of all bolts 104 can be found in [reference needed]. Figure 12 This completes the fixing process of the slip section, allowing it to be put into direct use afterwards.

[0055] First direction such as Figures 12 to 14 As shown by the middle arrow, that is, clockwise, in Figures 12 to 14 In the middle, all bolts 104 rotate in a counterclockwise direction in sequence.

[0056] In one embodiment, before one of the bolts 104 is rotated in the first direction by a first external force, the one-way gear ring 203 is rotated by a second external force, causing all the bolts 104 to rotate in the first direction, so as to pre-tighten all the bolts 104. The first external force is greater than the second external force.

[0057] The one-way gear ring 203 has retractable one-way teeth on its outer wall. When one bolt 104 is rotated in a first direction by a first external force, the one-way teeth allow that bolt 104 to rotate, so the one-way gear ring 203 and the other bolts 104 remain stationary. When the one-way gear ring 203 is rotated by a second external force, meshing occurs between the one-way gear ring 203 and the bolts 104, causing all bolts 104 to rotate in the first direction, thus pre-tightening all bolts 104. Furthermore, the first external force is circumferential to the bolts 104, and the second external force is circumferential to the one-way gear ring 203, with the first and second external forces rotating in opposite directions.

[0058] In one embodiment, see Figure 4 , Figure 5 and Figure 8A support rod 204 is rotatably mounted on the sleeve head 101. The tensioning wheel 202 is rotatably connected to the lower end of the support rod 204. The rotation axis of the support rod 204 is perpendicular to the first plane. The first plane passes through the axial and radial directions of the central hole 102, so that the tensioning wheel 202 can swing with the support rod 204 on the first plane. An elastic element 205 is provided between the support rod 204 and the sleeve head 101. The elastic element 205 causes the tensioning wheel 202 to touch the outside of the synchronizing element 201 or has a tendency to touch the outside of the synchronizing element 201.

[0059] When the degree of concavity of the recessed sections on both sides of the bolt 104 increases and decreases relative to the first preset value, the tensioning wheel 202 swings with the support rod 204 on the first plane because the size of the synchronizing member 201 in its trajectory direction is constant, so as to adapt to the change in the degree of concavity of the recessed section of the synchronizing member 201. At the same time, the elastic member 205 makes the tensioning wheel 202 always contact the outside of the synchronizing member 201.

[0060] In this embodiment, the support rod 204 is fixed to the sleeve head 101, and the tension wheel 202 is rotatably connected to the support rod 204 via a bearing. The axis of rotation of the tension wheel 202 is parallel to the length direction of the support rod 204. The elastic element 205 is preferably a V-shaped spring, with one end connected to the support rod 204 and the other end connected to the sleeve head 101. The elastic element 205 has an opening tendency so that the tension wheel 202 touches the outside of the synchronizing element 201 or has a tendency to touch the outside of the synchronizing element 201. In other embodiments not shown, the elastic element 205 may also be a compression spring and is provided with an arc-shaped guide rod; of course, the elastic element 205 may also be a torsion spring, which is disposed on the rotation axis of the support rod 204, with both ends fixed to the support rod 204 and the sleeve head 101 respectively.

[0061] In one embodiment, a through hole is provided on the slip portion along the axial direction of the central hole 102, and the bolt 104 is inserted into the through hole with clearance fit between the two; before the one-way gear ring 203 is rotated by the second external force, the distance between the support rod 204 and the axis of the central hole 102 gradually decreases from bottom to top, so that the length direction of the support rod 204 forms a first angle with the axis of the central hole 102. When the one-way gear ring 203 is rotated by the second external force, the first angle increases, and the elastic element 205 makes the inner side of all bolts 104 fully abut against the outer side of the one-way gear ring 203.

[0062] The sleeve head 101 has a threaded hole, and the bolt 104 is fitted into the threaded hole. The through hole can be a smooth hole or a threaded hole, preferably a threaded hole, which is fitted into the bolt 104 with a clearance fit. Initially, the length direction of the support rod 204 forms a first angle with the axial direction of the central hole 102, that is, the support rod 204 is inclined relative to the vertical direction and gradually approaches the axis of the central hole 102 from bottom to top, and the elastic element 205 is in a stored state. When the one-way gear ring 203 is rotated by the second external force, the bolt 104 is gradually screwed into the threaded hole on the sleeve head 101, which drives the synchronizing member 201 to gradually move upward, compressing and causing the support rod 204 to swing, that is, the first included angle increases, so that the elastic member 205 further stores force, and acts in the opposite direction on the synchronizing member 201 through the support rod 204, so that the synchronizing member 201 remains taut in its trajectory direction. At the same time, the synchronizing member 201 clamps the outer side of all bolts 104, so that the inner side of all bolts 104 fully abuts against the outer side of the one-way gear ring 203 to avoid the bolts 104 slipping on the one-way gear ring 203.

[0063] It is worth noting that when the locking part and the inner sleeve 103 are placed inside the sleeve head 101 as a whole, the bolt 104 and the threaded hole on the sleeve head 101 are in an unstable state due to the initial connection. Therefore, the synchronizing member 201 can tighten the outer side of all bolts 104, so that the bolts 104 are relatively close in the radial direction, thereby making the inner side of all bolts 104 fully abut against the outer side of the one-way gear ring 203. When the bolts 104 are gradually screwed into the threaded hole on the sleeve head 101, they are in a stable state due to the transition fit between the two.

[0064] In one embodiment, see Figure 3 , Figure 4 and Figure 8 The slip portion includes an inner slip 110 and an outer slip 111. The inner slip 110 is coaxially sleeved on the inner sleeve 103, and the inner wall of the inner slip 110 is provided with an obstruction member 112. The obstruction member 112 allows the inner sleeve 103 to move upward along the inner slip 110, while restricting the inner sleeve 103 from moving downward along the inner slip 110. A limiting member is provided in the central hole 102 to limit the distance the inner sleeve 103 moves upward. A through hole is opened on the outer slip 111, and the outer slip 111 is sleeved on the inner slip 110. The inner wall of the outer slip 111 and the outer wall of the inner slip 110 are both provided with conical surfaces 113 that can contact each other. The distance between the conical surface 113 and the axis of the central hole 102 gradually increases from bottom to top.

[0065] The inner clamp 110 is fitted onto the inner sleeve 103, and the obstruction member 112 allows the inner sleeve 103 to move in one direction. The outer clamp 111 hugs the inner clamp 110, and the whole assembly is installed at the bottom of the sleeve head 101 and fixed with bolts 104. Under the combined action of the gravity of the inner sleeve 103 and the obstruction member 112, as well as the action of the conical surface 113 between the outer clamp 111 and the inner clamp 110, the inner sleeve 103 is limited and fixed in multiple directions.

[0066] In this application, a WD-type slip is used, with both the inner slip 110 and the outer slip 111 being cylindrical. The inner slip 110 has an opening in its circumferential direction to facilitate the insertion of the inner sleeve 103 into the inner slip. The outer slip 111 can be divided into at least two parts in its circumferential direction to tightly grip the inner slip 110 in the circumferential direction. The obstruction 112 is an annular slip tooth with a one-way tooth structure. The limiting element is an annular step, coaxial with the central hole 102. The sleeve head 101 is provided with multiple injection valves 114. When the inner sleeve 103 abuts against the limiting element, the inner sleeve 103 is injection-sealed through the injection valves 114 and the injection tool. During this process, the injection valve 114 on the opposite side can be removed as an observation hole.

[0067] Additionally, the outer slip 111 has a first annular groove at its bottom, within which a support ring 115 is installed. When the bolt 104 is tightened, the support ring 115 is fixed relative to the outer slip 111. A rotating cylinder 116 is rotatably mounted on the support ring 115. A one-way gear ring 203 is disposed on the outer wall of the rotating cylinder 116, and a pin is threaded onto the side wall of the rotating cylinder 116. A second annular groove is provided on the inner wall of the support ring 115, with the end of the pin located within the second annular groove. The support ring 115 axially limits the rotating cylinder 116 and the one-way gear ring 203, while simultaneously allowing the rotating cylinder 116 and the one-way gear ring 203 to rotate circumferentially relative to the support ring 115 and the outer slip 111. The outer wall of the rotating cylinder 116 has multiple slots into which hand tools such as pry bars can be inserted to generate a second external force to rotate the one-way gear ring 203.

[0068] In one embodiment, see Figure 5 The bolt 104 has a first annular groove 206 along its circumference, the synchronizing member 201 is located in the first annular groove 206, and a contact member is provided in the first annular groove 206. The contact member is used to increase the static friction between the synchronizing member 201 and the first annular groove 206. The bolt 104 has a second annular groove 207 along its circumference, and the outer side of the one-way gear ring 203 is located in the second annular groove 207.

[0069] In this application, a hexagonal head bolt 104 is used, the tail of which is a regular hexagonal prism structure. A first annular groove 206 and a second annular groove 207 are both formed along the circumference of the bolt 104 at the regular hexagonal prism structure. The first annular groove 206 and the second annular groove 207 are spaced vertically apart to place the contact element and the synchronizing element 201 within the first annular groove 206, and the one-way gear ring 203 within the second annular groove 207. The contact element is a wavy surface arranged along the trajectory of the first annular groove 206. In other embodiments not shown, the contact element may also be a rough coating.

[0070] In one embodiment, see Figure 3 , Figure 6 and Figure 7 The lower end of the sleeve head 101 is provided with an outer sleeve 117, and the inner sleeve 103 is inserted into the outer sleeve 117. An adjustment part is provided between the sleeve head 101 and the outer sleeve 117. The adjustment part includes a first screw 118 and a second screw 119, both arranged axially along the center hole 102. Multiple first screws 118 and second screws 119 are equally spaced along the circumference of the center hole 102. The number of first screws 118 and second screws 119 is equal and they are alternately arranged along the circumference of the center hole 102. The first screw 118 passes through the sleeve head 101 and is threadedly connected to the outer sleeve 117. The second screw 119 is threadedly connected to the sleeve head 101 and its end abuts against the upper end of the outer sleeve 117.

[0071] First, connect the sleeve head 101 to the outer sleeve 117 using the first screw 118, and then adjust the included angle between the axes of the sleeve head 101 and the outer sleeve 117 using the second screw 119 until they are coaxial.

[0072] The lower end of the sleeve head 101 is fixed with an upper tray 120, and the upper end of the outer sleeve 117 is fixed with a lower tray 121. Both the upper tray 120 and the lower tray 121 are annular, and their axes coincide with the axis of the central hole 102 so that the inner sleeve 103 can pass through them. The first screw 118 passes through the upper tray 120 and is threaded to the lower tray 121. The second screw 119 is threaded to the upper tray 120 and its end abuts against the upper surface of the lower tray 121.

[0073] This invention also provides an oil wellhead control system with remote monitoring function, including a processor, a user terminal, and a pressure sensor 208. The pressure sensor 208 is disposed between the elastic element 205 and the casing head 101, and is used to detect the force between the elastic element 205 and the casing head 101. When all bolts 104 are tightened, the force between the elastic element 205 and the casing head 101 is the initial value. The processor obtains the detected value of the force between the elastic element 205 and the casing head 101, and calculates the absolute value of the difference between the detected value and the initial value. The processor determines whether all absolute values ​​are less than a second preset value. If so, the processor sends a normal signal to the user terminal; if not, the processor sends a loosening signal to the user terminal.

[0074] The processor detects the force between the elastic element 205 and the sleeve head 101 by the pressure sensor 208. The processor determines whether the absolute value of the difference between all detected values ​​and the initial value is less than the second preset value. If so, the processor sends a normal signal to the user terminal. If not, it means that the absolute value of the difference between a certain detected value and the initial value is greater than or equal to the second preset value, that is, there is a loose bolt 104. The processor sends a loosening signal to the user terminal to prompt the user to tighten the loose bolt 104 in time, thereby realizing remote real-time monitoring of the bolt 104, timely detection of the loosening of the slip, and intervention.

[0075] Among them, see Figure 5 and Figure 8 A pressure sensor 208 is mounted on the sleeve head 101, and one end of the elastic element 205 abuts against the working part of the pressure sensor 208. When all bolts 104 are tightened, the clamping process is completed, and the device can be directly put into use. At this time, the force between the elastic element 205 and the sleeve head 101 is the initial value, and the processor can obtain this initial value. During use, the pressure sensor 208 can detect the force between the elastic element 205 and the sleeve head 101 in real time or at intervals. Correspondingly, the processor can calculate the absolute value of the difference between the detected value and the initial value in real time or at intervals, and determine the relative magnitude of the absolute value and a second preset value.

[0076] In one embodiment, the number of bolts 104 is an integer greater than or equal to 4. When the detection values ​​on both sides of a single bolt 104 are greater than and less than the initial value, and the absolute values ​​on both sides of a single bolt 104 are greater than or equal to a second preset value, the processor sends an interval loosening signal to the user terminal. When the detection values ​​on both sides of two or more adjacent bolts 104 are greater than and less than the initial value, and the absolute values ​​on both sides of two or more adjacent bolts 104 are greater than or equal to the second preset value, and the absolute value between two or more adjacent bolts 104 is less than the second preset value, the processor sends a continuous loosening signal to the user terminal. When the detection values ​​on both sides of each bolt 104 are less than the initial value, and the absolute values ​​on both sides of each bolt 104 are greater than the second preset value and gradually decrease, the processor sends a complete loosening signal to the user terminal.

[0077] When the detection values ​​on both sides of a single bolt 104 are greater than and less than the initial values, and the absolute values ​​on both sides of a single bolt 104 are greater than or equal to the second preset value, the processor sends an interval loosening signal to the user terminal, and the single bolt 104 is the loosened object; when the detection values ​​on both sides of two or more adjacent bolts 104 are greater than and less than the initial values, and the absolute values ​​on both sides of two or more adjacent bolts 104 are greater than or equal to the second preset value, and the absolute value between two or more adjacent bolts 104 is less than the second preset value, the processor sends a continuous loosening signal to the user terminal, and the two or more adjacent bolts 104 are the loosened objects; when the detection values ​​on both sides of each bolt 104 are less than the initial value, and the absolute values ​​on both sides of each bolt 104 are greater than the second preset value and gradually decrease, the processor sends a complete loosening signal to the user terminal, and all bolts 104 become loose.

[0078] The preferred number of bolts 104 is 6. It is worth noting that when an intermittent loosening signal occurs, among all bolts 104, there may be only one loose bolt 104, or there may be two loose bolts 104 with an interval between them. The following provides an example illustrating the loosening of bolts 104. Figures 15 to 19 In the diagram, the loose bolt 104 is indicated by a dashed line.

[0079] For example, Figure 15 In the process, for the bottommost bolt 104, if the degree of indentation on its left side increases relative to the first preset value, the detected value is greater than the initial value; if the degree of indentation on its right side decreases relative to the first preset value, the detected value is less than the initial value. Simultaneously, the absolute values ​​on both sides of the bottommost bolt 104 are greater than or equal to the second preset value. Therefore, only the bottommost bolt 104 is loose. Based on this, Figure 16In the above scenario, for the bolt 104 at the upper right, if the degree of indentation on its upper side decreases relative to the first preset value, the detected value is less than the initial value; if the degree of indentation on its lower side increases relative to the first preset value, the detected value is greater than the initial value. Simultaneously, the absolute values ​​on both sides of the upper right bolt 104 are greater than or equal to the second preset value. Therefore, the two bolts 104 at the bottom and upper right are loose. In both of these cases, the processor sends an interval loosening signal to the user terminal.

[0080] For example, Figure 17 In the middle, for the bottommost and bottom right bolts 104, if the degree of indentation on the lower left side increases relative to the first preset value, the detected value is greater than the initial value; if the degree of indentation on the upper right side decreases relative to the first preset value, the detected value is less than the initial value. Simultaneously, the absolute values ​​on both sides are greater than or equal to the second preset value, and the absolute value between them is less than the second preset value. Therefore, there are two consecutive loose bolts 104 at the bottommost and bottom right. Figure 18 In the case of the bottom, bottom right, and top right bolts 104, if the degree of indentation on the lower left side of each bolt 104 increases relative to the first preset value, the detected value is greater than the initial value; if the degree of indentation on the upper right side decreases relative to the first preset value, the detected value is less than the initial value. Simultaneously, the absolute values ​​on both sides of each bolt 104 are greater than or equal to the second preset value, and the absolute value between the three bolts is less than the second preset value. Therefore, three consecutive bolts 104 (bottom, bottom right, and top right) are loose. In both of these cases, the processor sends a continuous loosening signal to the user terminal. The principle is the same when four or five bolts 104 are loose.

[0081] For example, Figure 19 In the process, when the detection values ​​on both sides of each bolt 104 are less than the initial value, and the absolute values ​​on both sides of each bolt 104 are greater than the second preset value and gradually decrease, the processor sends a loosening signal to the user terminal.

[0082] It is worth noting that in the above example, when the degree of concavity of the recessed section of the synchronizing component 201 in the figure increases or decreases relative to the first preset value, these two degrees of concavity do not necessarily reach the level of "flat" or "over-concave". In other words, when the degree of concavity of the recessed section of the synchronizing component 201 increases or decreases relative to the first preset value, it only indicates that the bolt 104 is loose, causing the degree of concavity of the current recessed section to change, and does not necessarily change to "flat" or "over-concave".

[0083] In one embodiment, the support rod 204 is equipped with an inclination sensor. When all bolts 104 are tightened, the inclination sensor is used to detect the rate of change of the first included angle within a preset time. The processor determines whether the rate of change is less than a third preset value. If so, the processor sends a normal signal to the user terminal; otherwise, the processor sends a pre-loosening signal to the user terminal.

[0084] When bolt 104 loosens, it moves downward, causing the synchronizing element 201 to gradually move downward. The force of the elastic element 205 pushes the support rod 204 to swing, that is, the first included angle decreases. When the rate of change of the first included angle is less than the third preset value within a preset time, the processor sends a normal signal to the user terminal; otherwise, it indicates that bolt 104 is in the process of loosening, and the processor sends a pre-loosening signal to the user terminal to remind the user to tighten bolt 104 in advance.

[0085] In addition, the tilt sensor can also detect the change in the first included angle within a preset time. The processor determines whether the change is less than a fourth preset value. If so, the processor sends a normal signal to the user terminal; otherwise, the processor sends a loosening signal to the user terminal.

[0086] The working principle of this invention is as follows:

[0087] The inner clamp 110 is fitted onto the inner sleeve 103, and the obstruction member 112 allows the inner sleeve 103 to move in one direction. The outer clamp 111 hugs the inner clamp 110, and the whole assembly is installed at the bottom of the sleeve head 101 and fixed with bolts 104. Under the combined action of the gravity of the inner sleeve 103 and the obstruction member 112, as well as the action of the conical surface 113 between the outer clamp 111 and the inner clamp 110, the inner sleeve 103 is limited and fixed in multiple directions.

[0088] During the tightening of bolts 104, the one-way gear ring 203 is first rotated by a second external force. The one-way gear ring 203 meshes with the bolts 104, causing all bolts 104 to rotate in the first direction to pre-tighten them. During the rotation of the one-way gear ring 203, the bolts 104 are gradually screwed into the threaded holes on the sleeve head 101, causing the synchronizing member 201 to gradually move upward, compressing and causing the support rod 204 to swing, i.e., the first included angle increases. This causes the elastic member 205 to further store force and act in the opposite direction on the synchronizing member 201 through the support rod 204, keeping the synchronizing member 201 taut in its trajectory direction. At the same time, the synchronizing member 201 clamps the outer side of all bolts 104, ensuring that the inner side of all bolts 104 fully abuts against the outer side of the one-way gear ring 203 to prevent slippage between the bolts 104 and the one-way gear ring 203.

[0089] Then, an external force is applied to rotate one of the bolts 104 in the first direction. The one-way gear ring 203 and the other bolts 104 remain stationary. Before rotation, the degree of concavity of all recessed sections is at a first preset value. After rotation, the degree of concavity of the recessed sections on both sides of the bolt 104 increases and decreases relative to the first preset value, respectively. When all bolts 104 are tightened, the degree of concavity of all recessed sections returns to the first preset value, thus completing the fixing process of the locking part, which can then be directly put into use. The degree of concavity of the recessed sections helps to manually judge the single rotation amount of the bolt 104. When the bolt 104 reaches its single rotation amount, it cannot continue to rotate, thus reminding and limiting the single rotation amount for the operator. This ensures that the cumulative rotation amount of each bolt 104 is basically consistent, so that the locking part is evenly stressed, avoiding misalignment between the locking part and the axis of the inner sleeve 103, or even jamming. At the same time, the tightening process of the bolts 104 is simple and easy to operate, ensuring consistency and precision in operation.

[0090] During subsequent use, the pressure sensor 208 detects the force between the elastic element 205 and the sleeve head 101. The processor determines whether the absolute value of the difference between all detected values ​​and the initial value is less than the second preset value. If so, the processor sends a normal signal to the user terminal. If not, it means that the absolute value of the difference between a certain detected value and the initial value is greater than or equal to the second preset value, that is, there is a loose bolt 104. The processor sends a loosening signal to the user terminal to prompt the user to tighten the loose bolt 104 in time, thereby realizing remote real-time monitoring of the bolt 104 and timely detection of the loosening of the slip. Specifically, when the detection values ​​on both sides of a single bolt 104 are greater than and less than the initial values, respectively, and the absolute values ​​on both sides of the single bolt 104 are greater than or equal to the second preset value, the processor sends an interval loosening signal to the user terminal, and the single bolt 104 is identified as the loosened bolt. When the detection values ​​on both sides of two or more adjacent bolts 104 are greater than and less than the initial values, respectively, and the absolute value between two or more adjacent bolts 104 is equal to the second preset value, and the absolute values ​​on both sides of two or more adjacent bolts 104 are greater than or equal to the second preset value, the processor sends a continuous loosening signal to the user terminal, and the two or more adjacent bolts 104 are identified as the loosened bolts. When the absolute values ​​on both sides of all bolts 104 are greater than the second preset value and gradually decrease, the processor sends a complete loosening signal to the user terminal, and all bolts 104 become loose. Additionally, the rate of change of the first included angle within a preset time can be detected by an tilt sensor. When this rate is less than a third preset value, the processor sends a pre-loosening signal to the user terminal, reminding the user to tighten the bolt 104 in advance.

[0091] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The above embodiments are merely illustrative of several implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. An oil wellhead device with remote monitoring function, characterized in that, The casing includes a wellhead and a casing head connected to its lower end. A central hole extends vertically through the casing head, into which an inner casing is coaxially inserted. The casing head has a locking mechanism, and bolts are inserted axially along the central hole onto the locking mechanism. Multiple bolts are evenly spaced along the circumference of the central hole and are threaded to the casing head to secure the inner casing. All bolts share a common annular and flexible synchronizing element on their outer side. The synchronizing element has a constant dimension along its trajectory. A tensioning wheel is located between adjacent bolts on the casing head. The tensioning wheel contacts the outer side of the synchronizing element to tension the synchronizing element, and the contacted position of the synchronizing element forms a recessed section in the direction of the central hole axis. The tensioning wheel is movably connected to the sleeve head so that the tensioning wheel can adapt to the change in the degree of recess of the recessed section. A one-way gear ring coaxial with the central hole is rotatably provided on the slip part. The outer side of the one-way gear ring abuts against the inner side of all bolts. The one-way gear ring allows the bolts to rotate in the first direction but restricts the bolts from rotating in the second direction. The bolts are tightened when rotating in the first direction and loosened when rotating in the second direction. When one of the bolts is rotated in the first direction by the first external force, the one-way gear ring and other bolts are stationary. Before rotation, the degree of concavity of all the recessed sections is the first preset value. After rotation, the degree of concavity of the recessed sections on both sides of the bolt increases and decreases relative to the first preset value, respectively. When all bolts are tightened, the degree of concavity of all the recessed sections is the first preset value.

2. The oil wellhead device with remote monitoring function according to claim 1, characterized in that, Before one of the bolts is rotated in the first direction by the first external force, the one-way gear ring is rotated by the second external force, which drives all the bolts to rotate in the first direction to pre-tighten all the bolts. The first external force is greater than the second external force.

3. The oil wellhead device with remote monitoring function according to claim 2, characterized in that, A support rod is rotatably provided on the sleeve head, and the tensioning wheel is rotatably connected to the lower end of the support rod. The rotation axis of the support rod is perpendicular to the first plane, which passes through the axial and radial directions of the central hole, so that the tensioning wheel can swing with the support rod on the first plane. An elastic element is provided between the support rod and the sleeve head, which makes the tensioning wheel touch the outside of the synchronizing element or tend to touch the outside of the synchronizing element.

4. The oil wellhead device with remote monitoring function according to claim 3, characterized in that, The slip section has a through hole along the central hole axially, and the bolt is inserted into the through hole with clearance fit between the two; before the one-way gear ring is rotated by the second external force, the distance between the support rod and the axis of the central hole gradually decreases from bottom to top, so that the length direction of the support rod forms a first angle with the axis of the central hole. When the one-way gear ring is rotated by the second external force, the first angle increases, and the elastic element makes the inner side of all bolts fully abut against the outer side of the one-way gear ring.

5. The oil wellhead device with remote monitoring function according to claim 1, characterized in that, The slip assembly includes an inner slip and an outer slip. The inner slip is coaxially fitted onto the inner sleeve, and the inner wall of the inner slip has an obstruction that allows the inner sleeve to move upward along the inner slip while restricting its downward movement. A limiting element is provided in the central hole to limit the upward movement distance of the inner sleeve. A through hole is opened on the outer slip, which is fitted onto the inner slip. Both the inner wall of the outer slip and the outer wall of the inner slip have conical surfaces that can contact each other, and the distance between the conical surfaces and the axis of the central hole gradually increases from bottom to top.

6. The oil wellhead device with remote monitoring function according to claim 1, characterized in that, The bolt has a first annular groove along its circumference, the synchronizing element is located in the first annular groove, and a contact element is provided in the first annular groove to increase the static friction between the synchronizing element and the first annular groove; the bolt has a second annular groove along its circumference, and the outer side of the one-way gear ring is located in the second annular groove.

7. The oil wellhead device with remote monitoring function according to claim 5, characterized in that, The lower end of the sleeve head is provided with an outer sleeve, and the inner sleeve is inserted into the outer sleeve. An adjustment part is provided between the sleeve head and the outer sleeve. The adjustment part includes a first screw and a second screw, both arranged axially along the center hole. Multiple first screws and second screws are equally spaced along the circumference of the center hole. The number of first screws and second screws is equal and they are arranged alternately along the circumference of the center hole. The first screw passes through the sleeve head and is threadedly connected to the outer sleeve. The second screw is threadedly connected to the sleeve head and its end abuts against the upper end of the outer sleeve.

8. A wellhead control system with remote monitoring function, applied to the wellhead device with remote monitoring function as described in claim 4, characterized in that, include: Processors and user terminals; A pressure sensor is placed between the elastic element and the sleeve head. The pressure sensor is used to detect the force between the elastic element and the sleeve head. When all bolts are tightened, the force between the elastic element and the sleeve head is the initial value. The processor obtains the detected value of the force between the elastic element and the sleeve head, and calculates the absolute value of the difference between the detected value and the initial value. The processor determines whether all absolute values ​​are less than a second preset value. If so, the processor sends a normal signal to the user terminal; otherwise, the processor sends a loose signal to the user terminal.

9. The oil wellhead control system with remote monitoring function according to claim 8, characterized in that, The number of bolts is an integer greater than or equal to 4; When the detection values ​​on both sides of a single bolt are greater than and less than the initial value, and the absolute values ​​on both sides of a single bolt are greater than or equal to the second preset value, the processor sends an interval loosening signal to the user terminal. When the detection values ​​on both sides of two or more adjacent bolts are greater than and less than the initial value, and the absolute values ​​on both sides of two or more adjacent bolts are greater than or equal to the second preset value, and the absolute value between two or more adjacent bolts is less than the second preset value, the processor sends a continuous loosening signal to the user terminal. When the detection values ​​on both sides of each bolt are less than the initial value, and the absolute values ​​on both sides of each bolt are greater than the second preset value and gradually decrease, the processor sends a loosening signal to the user terminal.

10. The oil wellhead control system with remote monitoring function according to claim 9, characterized in that, The support rod is equipped with an inclination sensor. When all bolts are tightened, the inclination sensor is used to detect the rate of change of the first included angle within a preset time. The processor determines whether the rate of change is less than a third preset value. If so, the processor sends a normal signal to the user terminal; otherwise, the processor sends a pre-loosening signal to the user terminal.

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