Wellhead four-way defect detection device

Abstract

The invention belongs to the technical field of nondestructive testing devices, and discloses a wellhead four-way defect detection device. The wellhead four-way defect detection device comprises a connecting assembly, a first detection assembly and a second detection assembly, the connecting assembly comprises a connecting sleeve and an adjusting piece, and the adjusting piece can rotate around the axis of the connecting sleeve and move in the length direction of the connecting sleeve; the first detection assembly comprises first connecting pieces and first measuring elements, the adjusting piece rotates to drive the four first connecting pieces to move in the radial direction of the connecting sleeve, and the first measuring elements connected to the first connecting pieces can detect the defects at the break angle of the wellhead four-way joint; the second detection assembly comprises a second connecting piece and a second measuring element, the adjusting piece moves to drive the second connecting piece to move in the length direction of the connecting sleeve, and the second measuring element connected to the second connecting piece can measure the defects of the straight pipeline of the wellhead four-way joint. According to the invention, the defects of the straight pipeline at the four-way corner of the wellhead can be detected simultaneously, and the detection efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nondestructive testing devices, in particular to a wellhead cross defect detection device. BACKGROUND

[0002] As the core carrier of oil exploitation, the oil production well is long-term in the complex working conditions of high pressure, strong corrosion and medium scouring, and the stable operation of its wellhead piping system is crucial. As a key component of the wellhead piping system of the oil production well, the wellhead cross not only bears the functions of junction, distribution and medium guiding of the multi-way oil production pipeline, but also is the core node connecting the wellhead Christmas tree, the throttling and well killing manifold and the conveying pipeline. During long-term operation, the corner part of the wellhead cross is prone to form local vortex due to the sudden change of fluid flow direction, resulting in erosion and stress concentration. The straight pipeline section is easily affected by the long-term corrosion and scouring of acidic medium and impurity particles in crude oil, and is prone to structural damage such as wall thickness thinning and cracking. If these defects are not found in time, it may cause safety accidents such as medium leakage and pipeline rupture, so it is necessary to regularly detect the corner part and the straight pipeline section of the wellhead cross.

[0003] At present, for the detection of the wellhead cross, the installation points are planned one by one in different detection areas such as the corner part and the straight pipeline section according to the structural characteristics of the wellhead cross during operation, and then the fixing, wiring and debugging of the detection elements are completed respectively. The detection steps are complicated, and the corner part and the straight pipeline section of the wellhead cross cannot be detected at the same time, further reducing the detection efficiency. SUMMARY

[0004] The purpose of the present application is to provide a wellhead cross defect detection device to improve the detection efficiency.

[0005] To achieve this purpose, the present application adopts the following technical solutions:

[0006] A wellhead cross defect detection device, comprising:

[0007] A connecting assembly comprising a connecting sleeve and an adjusting piece, the adjusting piece being connected to the inner wall of the connecting sleeve, and the adjusting piece being capable of rotating around the axis of the connecting sleeve and moving along the length direction of the connecting sleeve;

[0008] A first detection assembly comprising four first connecting pieces and four first measuring elements, the first connecting piece being slidingly connected to the connecting sleeve and being inserted into the adjusting piece, the adjusting piece being capable of driving the four first connecting pieces to move along the radial direction of the connecting sleeve through rotation, and each first connecting piece having one first measuring element connected to the end away from the connecting sleeve, the first measuring element being used for detecting the defects of the corner part of the wellhead cross;

[0009] A second detection assembly includes four second connecting members and four second measuring elements, the second connecting members are slidingly connected to the connecting sleeve, and the second connecting members are connected to the adjusting member at one end close to the connecting sleeve, the adjusting member is movable to drive the second connecting members to move along the length direction of the connecting sleeve, each second connecting member is connected to one second measuring element at one end away from the connecting sleeve, and the second measuring element is used to measure defects at the straight pipe of the wellhead four-way cross.

[0010] The wellhead four-way cross defect detection device, wherein the adjusting member is an adjusting column, and the adjusting member is threadedly connected to the inner wall of the connecting sleeve.

[0011] The wellhead four-way cross defect detection device, wherein the first detection assembly further includes a plurality of insertion rods, each first connecting member is fixedly connected to one insertion rod at one end away from the first measuring element, the adjusting member is provided with four arc-shaped grooves at one end close to the first connecting members, the arc-shaped grooves extend from the edge of the adjusting member to the axis of the adjusting member, and the four arc-shaped grooves are arranged in a ring array about the axis of the adjusting member, and each arc-shaped groove is inserted with one insertion rod.

[0012] The wellhead four-way cross defect detection device, wherein the second detection assembly includes a fixing plate, four second connecting members are fixedly connected to the fixing plate at one end away from the second measuring elements, and the other side of the fixing plate is rotationally connected to the end face of the adjusting member.

[0013] The wellhead four-way cross defect detection device, wherein the connecting sleeve is uniformly and spacedly provided with four limiting grooves about the axis of the connecting sleeve, the limiting grooves extend along the length direction of the connecting sleeve, and the second connecting members are connected to the adjusting member through the limiting grooves.

[0014] The wellhead four-way cross defect detection device, wherein the second detection assembly further includes an elastic member, the second connecting member is provided with a receiving groove at one end away from the connecting sleeve, the receiving groove extends along the length direction of the connecting sleeve, the groove bottom of the receiving groove is fixedly connected to the elastic member, and the other end of the elastic member is fixedly connected to the second measuring element.

[0015] The wellhead four-way cross defect detection device, wherein the connecting assembly further includes a force applying rod, one end of the force applying rod is fixedly connected to the adjusting member, and the other end of the force applying rod extends out of the connecting sleeve.

[0016] The wellhead four-way cross defect detection device, wherein the connecting assembly further includes a support seat, the support seat is provided with a mounting groove, and the outer side of the connecting sleeve is fixedly attached to the mounting groove.

[0017] The wellhead cross defect detection device, wherein the first measuring element comprises a cylindrical permanent magnet, a first excitation coil and a first receiving coil, the first excitation coil and the first receiving coil are located between the cylindrical permanent magnet and the tested piece, the first excitation coil and the first receiving coil are spirally wound, the first excitation coil is connected to an excitation device for exciting a transverse wave, and the first receiving coil is connected to a transverse wave receiver for receiving a echo signal of the transverse wave.

[0018] The wellhead cross defect detection device, wherein the second measuring element comprises a horseshoe-shaped permanent magnet, a second excitation coil and a second receiving coil, the second excitation coil and the second receiving coil are located between the horseshoe-shaped permanent magnet and the tested piece, the second excitation coil and the second receiving coil are serpentine back-and-forth wound, the second excitation coil is connected to an excitation device for exciting a surface wave, and the second receiving coil is connected to a surface wave receiver for receiving a echo signal of the surface wave.

[0019] The wellhead cross defect detection device provided by the application has the following beneficial effects:

[0020] The wellhead cross defect detection device provided by the application has the following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structure schematic view of the wellhead cross defect detection device provided by the embodiment of the application and the wellhead cross in a first perspective view;

[0022] Figure 2 is a structure schematic view of the wellhead cross defect detection device provided by the embodiment of the application and the wellhead cross in a second perspective view;

[0023] Figure 3is a structural schematic view of the wellhead cross defect detection device provided by the embodiment of the present application and the wellhead cross in the third visual angle;

[0024] Figure 4 is a structural schematic view of the wellhead cross defect detection device provided by the embodiment of the present application in the first visual angle;

[0025] Figure 5 is a structural schematic view of the wellhead cross defect detection device provided by the embodiment of the present application in the second visual angle;

[0026] Figure 6 is a structural schematic view of the wellhead cross defect detection device provided by the embodiment of the present application in the third visual angle;

[0027] Figure 7 is a structural schematic view of the connecting sleeve provided by the embodiment of the present application;

[0028] Figure 8 is a working principle schematic view of the first measuring element provided by the embodiment of the present application;

[0029] Figure 9 is a working principle schematic view of the second measuring element provided by the embodiment of the present application;

[0030] Figure 10 is a schematic view of the spiral winding mode provided by the embodiment of the present application;

[0031] Figure 11 is a schematic view of the serpentine back-and-forth winding mode provided by the embodiment of the present application.

[0032] In the figure:

[0033] 1, connecting assembly; 11, connecting sleeve; 111, limiting groove; 112, limiting hole; 12, adjusting piece; 121, arc-shaped groove; 13, force applying rod; 14, supporting seat;

[0034] 2, first detection assembly; 21, first connecting piece; 22, first measuring element; 221, cylindrical permanent magnet; 222, first excitation coil; 223, first receiving coil; 23, inserting rod;

[0035] 3, second detection assembly; 31, second connecting piece; 32, second measuring element; 321, horseshoe-shaped permanent magnet; 322, second excitation coil; 323, second receiving coil; 33, fixed plate; 34, elastic piece;

[0036] 100, wellhead cross;

[0037] 200, to-be-tested piece. DETAILED DESCRIPTION

[0038] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like component have the same or similar designations. The embodiments described below are presented by way of example to explain the present application and are not intended to limit the present application.

[0039] In the description of the present application, unless otherwise clearly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, can be fixedly connected, can be detachably connected, can be mechanically connected, can be electrically connected, can be directly connected, can be indirectly connected through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] In the description of the present application, unless otherwise clearly specified and limited, the first feature "on" or "below" the second feature can include that the first feature and the second feature are in direct contact, or the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0041] The technical solutions of the present application are further illustrated below in conjunction with the drawings and through specific embodiments.

[0042] As Figures 1-11As shown, the wellhead cross four defect detection device includes a connecting assembly 1, a first detection assembly 2 and a second detection assembly 3, the connecting assembly 1 includes a connecting sleeve 11 and an adjusting piece 12, the adjusting piece 12 is connected to the inner wall of the connecting sleeve 11, and the adjusting piece 12 can rotate around the axis of the connecting sleeve 11 and move along the length direction of the connecting sleeve 11; the first detection assembly 2 includes four first connecting pieces 21 and four first measuring elements 22, the first connecting piece 21 is slidingly connected to the connecting sleeve 11 and is inserted into the adjusting piece 12, the adjusting piece 12 can drive the four first connecting pieces 21 to move along the radial direction of the connecting sleeve 11 by rotating, one first measuring element 22 is connected to the end of each first connecting piece 21 away from the connecting sleeve 11, and the first measuring element 22 is used for detecting the defects at the corners of the wellhead cross 100; the second detection assembly 3 includes four second connecting pieces 31 and four second measuring elements 32, the second connecting piece 31 is slidingly connected to the connecting sleeve 11, and the end of the second connecting piece 31 close to the connecting sleeve 11 is connected to the adjusting piece 12, the adjusting piece 12 can drive the second connecting piece 31 to move along the length direction of the connecting sleeve 11 by moving, and one second measuring element 32 is connected to the end of each second connecting piece 31 away from the connecting sleeve 11, and the second measuring element 32 is used for measuring the defects at the straight pipes of the wellhead cross 100.

[0043] The wellhead cross four defect detection device provided by the application includes a connecting assembly 1, a first detection assembly 2 and a second detection assembly 3, in use, the connecting sleeve 11 serves as a unified mounting carrier, and integrates the first measuring assembly corresponding to the four corners of the wellhead cross 100 and the second detection assembly 3 corresponding to the four straight pipe sections of the wellhead cross 100, the four first connecting pieces 21 are driven to move along the radial direction of the connecting sleeve 11 by rotating the adjusting piece 12 to be clamped at the four corner positions of the wellhead cross 100, and then the first measuring element 22 detects the structural defects at the corners of the wellhead cross 100; the four second connecting pieces 31 are driven to move along the length direction of the connecting sleeve 11 by moving the adjusting piece 12, so that the second connecting piece 31 abuts against the four straight pipes of the wellhead cross 100, and then the second measuring element 32 detects the structural defects of the straight pipes of the wellhead cross 100, rotating and moving the adjusting piece 12 makes the first measuring element 22 and the second measuring element 32 simultaneously located at the detection position, and the corners and the straight pipes of the wellhead cross 100 are detected, which improves the detection efficiency. At the same time, the first measuring element 22 and the second measuring element 32 are synchronously measured, which avoids the measurement error caused by different working conditions and improves the detection accuracy, and provides a reliable basis for subsequent defect comprehensive evaluation and risk prediction.

[0044] The adjusting piece 12 can rotate and abut against the inner wall of the connecting sleeve 11, which can rotate around the axis of the connecting sleeve 11 and move along the length direction of the connecting sleeve 11.

[0045] In the embodiment, the adjusting member 12 is an adjusting column, and the adjusting member 12 is threadedly connected to the inner wall of the connecting sleeve 11. When the adjusting member 12 is threadedly connected, the adjusting member 12 can rotate around the axis of the connecting sleeve 11 and can move along the length direction of the connecting sleeve 11, so that the operation steps are reduced and the detection efficiency is improved.

[0046] Specifically, the outer circumferential surface of the adjusting member 12 is provided with a first connecting thread, and the inner wall of the connecting sleeve 11 is provided with a second connecting thread.

[0047] The connecting member can be directly connected to the adjusting member 12 or indirectly connected to the adjusting member 12. For example, referring to Figure 5 , the first detection assembly 2 further comprises a plug rod 23, one end of each first connecting member 21 away from the first measuring element 22 is fixedly connected with one plug rod 23, and the end of the adjusting member 12 close to the first connecting member 21 is provided with four arc-shaped grooves 121 extending from the edge of the adjusting member 12 to the axis of the adjusting member 12, and the four arc-shaped grooves 121 are arranged in an annular array about the axis of the adjusting member 12, and one plug rod 23 is inserted into each arc-shaped groove 121. By rotating the adjusting member 12, the arc-shaped groove 121 will also rotate, and then gradually extrude the plug rod 23, so that the plug rod 23 gradually approaches the axis of the adjusting member 12. Since the plug rod 23 is fixedly connected with the first connecting member 21, the movement of the plug rod 23 will drive the first connecting member 21 to approach the axis of the connecting shaft, so as to realize folding and then clamping the corner position of the wellhead four-way joint 100.

[0048] In other embodiments, the end surface of the adjusting member 12 can be provided with an arc-shaped sliding rail, and the plug rod 23 is connected to the arc-shaped sliding rail.

[0049] Specifically, referring to Figures 5 to 7 , the connecting sleeve 11 is provided with four limiting holes 112, and the limiting holes 112 are uniformly and spacedly arranged about the axis of the connecting sleeve 11. The size and shape of the limiting hole 112 are not limited in the embodiment, and for example, the cross section of the first connecting member 21 is rectangular, and the limiting hole 112 is a rectangular hole, so as to ensure that the first connecting member 21 slides in the radial direction of the limiting hole 112, avoid twisting, and improve the motion stability.

[0050] In the embodiment, the first connecting member 21 is an L-shaped plate, which can ensure that the end of the first connecting member 21 away from the connecting sleeve 11 clamps the corner of the wellhead four-way joint.

[0051] The second connecting member 31 can be fixedly connected to the adjusting member 12 or indirectly connected to the adjusting member 12. For example, referring to Figure 1 and Figure 6The second detection assembly 3 comprises a fixed plate 33, and one ends of the four second connecting pieces 31 away from the second measuring element 32 are fixedly connected to the fixed plate 33. The other side of the fixed plate 33 is rotationally connected to the end face of the adjusting piece 12, so that the adjusting piece 12 can drive the second connecting piece 31 to move during the rotation of the adjusting piece 12, and the second measuring element 32 can detect the defects of the straight pipeline of the wellhead four-way junction 100.

[0052] Specifically, the second connecting piece 31 is fixedly connected to one side of the fixed plate 33 through the existing bolt. The end face of the adjusting piece 12 is provided with a circular groove. The groove wall of the circular groove is in interference fit with the outer ring of the existing bearing. The inner ring of the bearing is in interference fit with the outer circumferential surface of the fixed plate 33, so as to realize the rotational connection between the fixed plate 33 and the adjusting piece 12. The smooth connection of the bearing can prevent the torque of the rotating process of the adjusting piece 12 from being transmitted to the second connecting piece 31, so as to avoid the interference between the second connecting piece 31 and the connecting sleeve 11.

[0053] In other embodiments, the end face of the adjusting piece 12 can be fixedly provided with a mounting protrusion. The mounting protrusion is in interference fit with the inner ring of the existing bearing. The end face of the fixed plate 33 is provided with a circular groove. The outer ring of the bearing is in interference fit with the groove wall of the circular groove, so as to realize the rotational connection between the fixed plate 33 and the adjusting piece 12.

[0054] Further, referring to Figure 5 and Figure 7 , the connecting sleeve 11 is uniformly and spacedly provided with four limiting grooves 111 around the axis of the connecting sleeve 11. The limiting grooves 111 extend along the length direction of the connecting sleeve 11. The second connecting piece 31 is connected to the adjusting piece 12 through the limiting grooves 111. The groove wall of the limiting groove 111 can limit the second connecting piece 31, so as to prevent the second connecting piece 31 from deflecting. The second connecting piece 31 can move along the extension direction of the limiting groove 111, i.e., along the length direction of the connecting sleeve 11, so as to improve the accuracy of movement and facilitate the second measuring element 32 to be attached to the straight pipeline of the wellhead four-way junction 100 for detection.

[0055] Specifically, referring to Figure 1 , Figure 3 and Figure 5 , the second detection assembly 3 further comprises an elastic piece 34. One end of the second connecting piece 31 away from the connecting sleeve 11 is provided with a containing groove extending along the length direction of the connecting sleeve 11. The groove bottom of the containing groove is fixedly connected with the elastic piece 34. The other end of the elastic piece 34 is fixedly connected to the second measuring element 32. The elastic piece 34 is installed in the containing groove, so that the second measuring element 32 can be telescopic in the containing groove. During the process that the adjusting piece 12 drives the second connecting piece 31 to approach the wellhead four-way junction 100, when the second measuring element 32 contacts the straight pipeline of the wellhead four-way junction 100, the second measuring element 32 forms a soft connection with the wellhead four-way junction 100, so as to prevent the damage of the second measuring element 32 caused by excessive extrusion force.

[0056] In order to facilitate the rotation of the adjusting member 12, in the embodiment, the connecting assembly 1 further comprises a force applying rod 13, one end of the force applying rod 13 is fixedly connected to the adjusting member 12, and the other end extends out of the connecting sleeve 11, so that the detection personnel can directly apply force to the adjusting member 12 from the outside without needing to stretch into the inside of the connecting sleeve 11 or close to the narrow gap of the wellhead cross 100, thereby avoiding space first.

[0057] Specifically, the force applying rod 13 can be made into a T-shaped rod structure, which increases the force arm, facilitates rotation, and reduces the labor intensity of the detection personnel. A hexagonal groove can also be formed on the end face of the force applying rod 13 away from the adjusting member 12, which facilitates the rotation of the force applying rod 13 by a hexagonal wrench.

[0058] In the embodiment, referring to Figure 1 , the connecting assembly 1 further comprises a support seat 14, the support seat 14 is provided with a mounting groove, the outer side of the connecting sleeve 11 is fixedly attached to the mounting groove, and the mounting groove is attached to the outer peripheral surface of the connecting sleeve 11, thereby increasing the contact area, reducing the stress, and improving the service life.

[0059] Specifically, the connecting sleeve 11 can be adhesively fixed to the support seat 14 or welded to the support seat 14.

[0060] Further, the support seat 14 is also capable of lifting to adjust the height of the connecting sleeve 11, so that the first detection assembly 2 and the second detection assembly 3 are kept consistent with the height of the wellhead cross 100 to be detected, and at the same time, the support seat 14 moves on the horizontal plane to further adjust the position of the connecting sleeve 11, so as to ensure that the first measuring element 22 can be clamped at the corner of the wellhead cross 100, and the second measuring element 32 can abut against the straight pipeline of the wellhead cross 100.

[0061] The first measuring element 22 is used to detect structural defects at the corner of the wellhead cross 100, in the embodiment, referring to Figure 8 and Figure 10 , the first measuring element 22 comprises a cylindrical permanent magnet 221, a first excitation coil 222 and a first receiving coil 223, the first excitation coil 222 and the first receiving coil 223 are both located between the cylindrical permanent magnet 221 and the test piece 200, the first excitation coil 222 and the first receiving coil 223 are spirally wound, the first excitation coil 222 is connected to an excitation device for exciting a shear wave, and the first receiving coil 223 is connected to a shear wave receiver for receiving a return signal of the shear wave. The coil and the permanent magnet are coaxially arranged, the magnetic field distribution is uniform, the signal interference is reduced, and the accuracy of defect detection is ensured.

[0062] Specifically, the cylindrical permanent magnet 221 has a diameter of 15mm-25mm and a height of 30mm-50mm, and is preferably made of neodymium iron boron permanent magnet; see [link to documentation]. Figure 8 The first excitation coil 222 and the first receiving coil 223 are placed between the test piece and the cylindrical permanent magnet, and the winding method is as follows: Figure 10 The spiral circular coil shown is selected in a one-to-one excitation and one-to-receive mode with the first excitation coil 222 at the bottom and the first receiving coil 223 at the top. This allows the transverse wave excitation and echo reception paths to be adapted to the detection scenario at the bend. The magnetic field coupling is stable and the signal interference is small, which significantly improves the accuracy and sensitivity of defect detection.

[0063] To improve the detection efficiency of the first measuring element 22, appropriate lift-up distances need to be set using a lift-up plate between the first excitation coil 222 and the first receiving coil 223, between the first excitation coil 222 and the test piece 200, and between the first receiving coil 223 and the cylindrical permanent magnet 221. Specifically, the lift-up distance between the first excitation coil 222 and the first receiving coil 223 is 4mm-5mm, the lift-up distance from the first receiving coil 223 to the cylindrical permanent magnet 221 is 0-2mm, and the distance between the first excitation coil 222 and the test piece 200 is 4mm-5mm.

[0064] During the testing process, the cylindrical permanent magnet 221 generates a static bias magnetic field in the vertical direction. The first excitation coil 222 is connected to the excitation device to receive the excitation pulse signal and generate a dynamic alternating magnetic field. The first receiving coil 223 is connected to the transverse wave receiver to receive the echo signal of the transverse wave. The test piece 200 is placed below the first excitation coil 222 and the first receiving coil 223. When a high-frequency, high-current is passed through the first excitation coil 222, the test piece 200 generates eddy currents of the same frequency within the skin layer. Under the action of the static magnetic field, the particles on the surface of the ferromagnetic test piece are subjected to Lorentz force, magnetization force, and magnetostrictive force, with the Lorentz force playing a major role. For non-ferromagnetic components, only the Lorentz force exists. Furthermore, in ferromagnetic materials, the tangential components of the magnetization force and the Lorentz force reinforce each other, which is beneficial for generating transverse waves.

[0065] The first measuring element 22 can be equipped with a housing to house the first excitation coil 222, the first receiving coil 223, and the cylindrical permanent magnet 221. The method of installation is a conventional technique in the field and will not be described in detail here.

[0066] Specifically, the to-be-tested piece 200 can be a Christmas tree of a sea gas well platform, which belongs to a ferromagnetic material. When the first excitation coil 222 is connected with a high-frequency large current, eddy current of the same frequency is induced in the skin layer on the surface of the to-be-tested piece 200. Under the action of the vertical static magnetic field generated by the Nd-Fe-B permanent magnet, the particles on the surface of the to-be-tested piece 200 are subjected to an electromagnetic force, thereby generating ultrasonic transverse waves. When the ultrasonic transverse waves propagate downward to the bottom surface of the to-be-tested piece 200 and are reflected back to the surface of the to-be-tested piece 200, the surface of the to-be-tested piece 200 is cut by the magnetic induction lines due to mechanical vibration, thereby generating an induced electromotive force and eddy current. Then, the alternating magnetic field of the eddy current is acquired by the first receiving coil 223, and the reception of the ultrasonic waves is completed.

[0067] The second measuring element 32 is used for detecting structural defects of the straight pipe of the wellhead cross 100. In the embodiment, referring to Figure 9 and Figure 11 , the second measuring element 32 includes a horseshoe-shaped permanent magnet 321, a second excitation coil 322 and a second receiving coil 323. The second excitation coil 322 and the second receiving coil 323 are both located between the horseshoe-shaped permanent magnet 321 and the to-be-tested piece 200. The second excitation coil 322 and the second receiving coil 323 are both in a serpentine back-and-forth winding mode. The second excitation coil 322 is connected to an excitation device for exciting surface waves. The second receiving coil 323 is connected to a surface wave receiver for receiving echo signals of the surface waves. The second measuring element 32 can adapt to the detection scene of the straight pipe of the wellhead cross 100, and can realize efficient and accurate detection of defects.

[0068] Specifically, the second excitation coil 322 and the second receiving coil 323 are in a serpentine back-and-forth winding mode. The material of the horseshoe-shaped permanent magnet 321 is preferably a Nd-Fe-B permanent magnet. The horseshoe-shaped permanent magnet 321 can be formed by stacking square Nd-Fe-B permanent magnets Figure 9 in a horseshoe shape. The height of the horseshoe-shaped permanent magnet 321 is 20mm-50mm, the length is 30mm-50mm, and the width is 5mm-25mm.

[0069] Referring to Figure 9 , the second excitation coil 322 and the second receiving coil 323 are placed between the to-be-tested piece 200 and the horseshoe-shaped permanent magnet 321. The back-and-forth serpentine coil shown in Figure 11 is used. A down-excitation and up-reception mode is selected. The second excitation coil 322 is at the bottom, and the second receiving coil 323 is at the top. The surface wave excitation strength and the coupling efficiency of the to-be-tested piece 200 can be enhanced. The magnetic field is uniformly covered, and the signal interference is small. The sensitivity and accuracy of the straight pipe defect detection are improved.

[0070] In order to improve the detection efficiency of the second measuring element 32, the appropriate lift-off distance is set by the lift-off plate between the second excitation coil 322 and the second receiving coil 323, between the second excitation coil 322 and the test piece 200, and between the second receiving coil 323 and the cylindrical permanent magnet 221. Specifically, the lift-off distance between the second excitation coil 322 and the second receiving coil 323 is 4-5 mm, the lift-off distance from the second receiving coil 323 to the cylindrical permanent magnet 221 is 0-2 mm, and the distance between the second excitation coil 322 and the test piece 200 is 4-5 mm.

[0071] During the detection process, the horseshoe-shaped permanent magnet 321 can generate a horizontal static bias magnetic field; the second excitation coil 322 is connected to the excitation device for accessing the excitation pulse signal to generate a dynamic alternating magnetic field; the test piece 200 is arranged below the coil, and the thickness of the test piece 200 is greater than the skin depth. The static bias magnetic field generated by the horseshoe-shaped permanent magnet 321 is horizontal, the second excitation coil 322 and the second receiving coil 323 are serpentine coils, equal and opposite currents are passed through each adjacent two wires of the second excitation coil 322 and the second receiving coil 323, and the currents are high-frequency alternating currents. The induced eddy current generates a force on the surface of the metal test piece under the action of the horizontal bias magnetic field. The thickness of the measured metal test piece is greater than the skin depth caused by the eddy current, and the generated ultrasonic wave is the surface wave propagating to both sides of the wave source.

[0072] The second measuring element 32 can be installed by setting the shell to install the second excitation coil 322, the second receiving coil 323, and the horseshoe-shaped permanent magnet 321. How to install is a conventional technical means in the art, which will not be repeated here.

[0073] The test piece 200 can be a pipeline between the Christmas trees of the offshore gas well platform, which belongs to a ferromagnetic material. When the second excitation coil 322 passes through a high-frequency large current, the same frequency eddy current is induced in the skin layer on the surface of the test piece 200. Under the action of the horizontal static magnetic field generated by the horseshoe-shaped permanent magnet 321 of the cobalt-iron-boron material, the electromagnetic force is generated on the surface of the test piece 200, thereby generating an ultrasonic surface wave. The ultrasonic surface wave propagates to both sides and is reflected back to the pipe wall at the four-way structure, and is acquired by the second receiving coil 323 to complete the reception of the ultrasonic wave.

[0074] It should be noted that the first measuring element 22 is used for surface flaw detection at the corner of the wellhead cross 100, and the second measuring element 32 is used for detecting the wall thickness of the straight pipe section of the wellhead cross 100, and then evaluating the structural defects. The first measuring element 22 is that the first excitation coil 222 is placed on the test piece 200, the first receiving coil 223 and the cylindrical permanent magnet 221 are sequentially stacked on the first excitation coil 222, the high-frequency current is input to the first excitation coil 222, the alternating electromagnetic field is generated around the first excitation coil 222, the induced eddy current is formed on the surface of the test piece 200, the Lorentz force is generated in the test piece 200 under the action of the static bias magnetic field provided by the cylindrical permanent magnet 221, and then the ultrasonic transverse wave signal is generated in the test piece 200.

[0075] The second measuring element 32 is different from the first measuring element 22, and a horseshoe-shaped permanent magnet and a snakelike coil are used. The second excitation coil 322 and the second receiving coil 323 are placed above the test piece 200, the horseshoe-shaped permanent magnet 321 is placed directly above the second excitation coil 322 and the second receiving coil 323, the horseshoe-shaped permanent magnet 321 provides a horizontal magnetic field with a magnetic field strength B2, the current direction of every two adjacent wires of the snakelike coil is opposite to each other, and the current is high-frequency alternating current with a size I. At this time, the induced eddy current I' is generated in the area below the coil on the surface of the test piece 200, the induced eddy current is subjected to the vertical upward or downward force Fs under the action of the horizontal bias magnetic field B2, and then the surface wave propagating to both sides is formed.

[0076] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manner of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the implementation manners are not required or can not be exhausted. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A device for detecting defects in a wellhead cross, characterized by The utility model relates to a kind of wellhead four-way detection device, including: Connecting assembly (1), including connecting sleeve (11) and adjusting piece (12), the adjusting piece (12) is connected to the inner wall of the connecting sleeve (11), and the adjusting piece (12) can rotate around the axis of the connecting sleeve (11) and move along the length direction of the connecting sleeve (11); First detection assembly (2), including four first connecting pieces (21) and four first measuring elements (22), the first connecting piece (21) is slidingly connected to the connecting sleeve (11) and is inserted into the adjusting piece (12), the adjusting piece (12) can drive four first connecting pieces (21) to move along the radial direction of the connecting sleeve (11) by rotating, and one first measuring element (22) is connected to the end of each first connecting piece (21) away from the connecting sleeve (11), and the first measuring element (22) is used to detect defects at the corner of wellhead four-way (100); Second detection assembly (3), including four second connecting pieces (31) and four second measuring elements (32), the second connecting piece (31) is slidingly connected to the connecting sleeve (11), and the end of the second connecting piece (31) close to the connecting sleeve (11) is connected to the adjusting piece (12), the adjusting piece (12) can drive the second connecting piece (31) to move along the length direction of the connecting sleeve (11) by moving, and one second measuring element (32) is connected to the end of each second connecting piece (31) away from the connecting sleeve (11), and the second measuring element (32) is used to measure defects at the straight pipeline of wellhead four-way (100).

2. The wellhead four-way crossover defect detection apparatus of claim 1, wherein, The adjusting piece (12) is an adjusting column, and the adjusting piece (12) is threadedly connected to the inner wall of the connecting sleeve (11).

3. The wellhead four-way crossover defect detection apparatus of claim 2, wherein, The first detection assembly (2) further includes a plug rod (23), and one plug rod (23) is fixedly connected to the end of each first connecting piece (21) away from the first measuring element (22), the end of the adjusting piece (12) close to the first connecting piece (21) is provided with four arc-shaped grooves (121), the arc-shaped grooves (121) extend from the edge of the adjusting piece (12) to the axis of the adjusting piece (12), and the four arc-shaped grooves (121) are arranged in an annular array about the axis of the adjusting piece (12), and one plug rod (23) is inserted into each arc-shaped groove (121).

4. The wellhead four-way crossover defect detection apparatus of claim 2, wherein, The second detection assembly (3) includes a fixed plate (33), and the end of each second connecting piece (31) away from the second measuring element (32) is fixedly connected to the fixed plate (33), and the other side of the fixed plate (33) is rotatably connected to the end face of the adjusting piece (12).

5. The wellhead four-way crossover defect detection apparatus of claim 1, wherein, The connecting sleeve (11) is uniformly spaced about its axis and provided with four limiting grooves (111), the limiting grooves (111) extend along the length direction of the connecting sleeve (11), and the second connecting piece (31) is connected to the adjusting piece (12) by penetrating the limiting groove (111).

6. The wellhead four-way crossover defect detection apparatus of claim 1, wherein, The second detection component (3) further comprises an elastic member (34), one end of the second connecting member (31) is provided with a containing groove away from the connecting sleeve (11), the containing groove extends along the length direction of the connecting sleeve (11), the groove bottom of the containing groove is fixedly connected with the elastic member (34), and the other end of the elastic member (34) is fixedly connected to the second measurement element (32).

7. The wellhead four-way crossover defect detection apparatus of any one of claims 1-6, wherein, The connecting assembly (1) further comprises a force applying rod (13), one end of the force applying rod (13) is fixedly connected to the adjusting member (12), and the other end of the force applying rod (13) extends out of the connecting sleeve (11).

8. The wellhead four-way crossover defect detection apparatus of any one of claims 1-6, wherein, The connecting assembly (1) further comprises a supporting seat (14), the supporting seat (14) is provided with a mounting groove, and the outer side of the connecting sleeve (11) is fixedly attached to the mounting groove.

9. The wellhead four-way crossover defect detection apparatus of any one of claims 1-6, wherein, The first measurement element (22) comprises a cylindrical permanent magnet (221), a first excitation coil (222) and a first receiving coil (223), the first excitation coil (222) and the first receiving coil (223) are located between the cylindrical permanent magnet (221) and the tested member (200), the first excitation coil (222) and the first receiving coil (223) are spirally wound, the first excitation coil (222) is connected to an excitation device and is used for exciting a transverse wave, and the first receiving coil (223) is connected to a transverse wave receiver and is used for receiving a echo signal of the transverse wave.

10. The wellhead four-way crossover defect detection apparatus of any one of claims 1-6, wherein, The second measurement element (32) comprises a horseshoe-shaped permanent magnet (321), a second excitation coil (322) and a second receiving coil (323), the second excitation coil (322) and the second receiving coil (323) are located between the horseshoe-shaped permanent magnet (321) and the tested member (200), the second excitation coil (322) and the second receiving coil (323) are serpentine back and forth wound, the second excitation coil (322) is connected to an excitation device and is used for exciting a surface wave, and the second receiving coil (323) is connected to a surface wave receiver and is used for receiving a echo signal of the surface wave.

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