Removable direct reading pressure gauge and its holder

Abstract

The application relates to a removable direct-reading pressure gauge and a supporting barrel thereof, characterized in that the lower end of the direct-reading pressure gauge is provided with an electromagnetic coupling head, and the lower end of the pressure gauge lower-inlet cavity in the supporting barrel of the direct-reading pressure gauge is provided with a corresponding electromagnetic coupling seat. The direct-reading pressure gauge is lowered into the well by using a steel wire tool, the electromagnetic coupling head at the lower end of the direct-reading pressure gauge is tightly combined with the corresponding electromagnetic coupling seat in the supporting barrel, power supply of the pressure gauge and data transmission to the ground direct-reading equipment are realized through electromagnetic coupling. The special steel wire launching and recovery tool is used for launching and recovering through the oil pipe, the well is not stopped and production is not stopped, the oil pipe column does not need to be lifted, the problem that the existing technology needs to shut down the well, stop production and lift and lower all oil pipes to replace a new pressure gauge is solved. Meanwhile, the mode that two side coupling coils are opposite to the electromagnetic coupling head coil of the pressure gauge in the middle saves the radial space of the pressure gauge supporting barrel to the maximum, the same outer diameter as that of the existing same-specification pressure gauge supporting barrel is kept, and the normal application in the existing casing can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas resource exploitation, and particularly relates to a retrievable direct-reading pressure gauge for measuring downhole pressure, temperature, flow rate and other physical parameters and a holder thereof. BACKGROUND

[0002] In the process of oilfield development and production, the pressure, temperature, fluid flow rate and other physical quantity data of downhole formation often need to be tested in the stages of oil testing, well logging and oil production. A commonly used measuring instrument is a pressure gauge. Although it is usually called a pressure gauge, the downhole physical quantities measured by the pressure gauge are not only pressure, but also temperature, and sometimes fluid flow rate and even water content. The pressure gauge is divided into a storage type and a direct-reading type. The storage type pressure gauge is lowered into the downhole with battery power and storage, and is taken out of the downhole after a period of time, and the measured data is read by a special instrument. The storage type pressure gauge needs to be lowered into the well for both deployment and recovery, and sometimes needs to shut down production, which is a cost. In many cases, such as deep wells, multiple or long-term monitoring of different production layers at different depths in a well is required. At this time, considering the cost of multiple well operations and the working time of the battery, the direct-reading pressure gauge is more economical and effective.

[0003] The principle of the direct-reading pressure gauge is shown in Figure 18 The direct-reading pressure gauge is placed in the holder 1 and lowered into the casing 10 at the depth of each production layer to be measured along with the oil pipe 9. The direct-reading pressure gauge is directly and fixedly electrically connected to the steel pipe cable 7, which is connected to the ground direct-reading equipment 12 through the Christmas tree 11. The direct-reading equipment 12 supplies power to the downhole direct-reading pressure gauge and reads the measurement data transmitted back by the pressure gauge, thereby realizing real-time monitoring of the required physical parameters in the downhole. The steel pipe cable is fixed to the oil pipe 9 by the steel pipe cable fixing clamp 8 arranged at appropriate intervals, and has sufficient strength and electrical insulation, thereby ensuring reliable power supply and data transmission between the ground direct-reading equipment 12 and each direct-reading pressure gauge in the downhole.

[0004] However, the direct-reading pressure gauge has a difficult-to-overcome disadvantage that it is difficult to ensure that the direct-reading pressure gauge mainly composed of electronic devices does not fail during several months or even years of monitoring at a high temperature, high pressure and high corrosive environment in the downhole at a conventional cost. Once a failure occurs, the well needs to be shut down and production needs to be stopped, and the entire oil pipe needs to be operated to replace the new pressure gauge, which incurs huge costs of shutdown and operation.

[0005] In the current production practice, there is an urgent need for a direct-reading pressure gauge that can be replaced without shutting down the well and moving the production pipe column. Moreover, the holder of the pressure gauge cannot be too large in outer diameter under the premise of ensuring a sufficient central hole diameter, and can be normally applied in the existing casing. SUMMARY

[0006] The problem to be solved by the present application is:

[0007] The present application designs a direct-reading pressure gauge which can be replaced without shutting down the well and moving the production string, and a carrier cylinder for carrying the pressure gauge in the well;

[0008] Under the premise of ensuring sufficient central hole diameter, the carrier cylinder of the pressure gauge can be normally applied in the existing casing.

[0009] The present application is a removable direct-reading pressure gauge and a carrier cylinder thereof, wherein the removable direct-reading pressure gauge is characterized in that: the lower end of the direct-reading pressure gauge is provided with an electromagnetic coupling head, which includes a long flat body parallel to the axis of the direct-reading pressure gauge, the cross section of the long flat body is constant, and the area of the long flat body is smaller than the cross section area of the main body of the direct-reading pressure gauge; the cross section shape of the long flat body is quadrilateral, one pair of opposite sides are parallel and equal straight sides, and the other pair of opposite sides are two equal arcs on the same circle, the radius of the arcs is equal to the radius of the outer diameter of the main body of the direct-reading pressure gauge; the long flat body contains an electromagnetic coupling head peek coil package and an electromagnetic coupling head magnetically conductive body which are coaxially and tightly sleeved, the electromagnetic coupling head peek coil package is outside, and the electromagnetic coupling head magnetically conductive body is inside as a magnetically conductive core body; the electromagnetic coupling head coil is wrapped inside the electromagnetic coupling head peek coil package, and the axial direction of the coil is perpendicular to the axis of the direct-reading pressure gauge and the straight sides of the cross section of the long flat body.

[0010] Further, the removable direct-reading pressure gauge is further characterized in that: the electromagnetic coupling head magnetically conductive body contains ferrite or silicon steel sheet or silicon steel sheet.

[0011] Further, the removable direct-reading pressure gauge is further characterized in that: from the direction of the normal line of the plane of the long flat body, the profiles of the electromagnetic coupling head peek coil package, the electromagnetic coupling head magnetically conductive body and the electromagnetic coupling head coil are long circular.

[0012] Further, the removable direct-reading pressure gauge is further characterized in that: the electromagnetic coupling head peek coil package and the electromagnetic coupling head coil are integrally formed by pressure casting of the peek material and the wound coil.

[0013] The present application also includes a carrier cylinder for carrying the above-mentioned removable direct-reading pressure gauge, which includes:

[0014] a carrier cylinder body, an inner and outer electric connection pipe of the carrier cylinder, a branch bridging box and a steel pipe cable;

[0015] the carrier cylinder body is provided with an upper connecting head, a lower connecting head, a full-diameter central hole and a cylindrical pressure gauge running-in cavity, and the upper connecting head and the lower connecting head are connected with the tubing in the well, respectively;

[0016] The axis of the full-bore central hole and the axis of the pressure gauge landing cavity are parallel to each other, and the common plane of the two axes is plane M;

[0017] A channel is arranged between the full-bore central hole and the upper part of the pressure gauge landing cavity, which allows the direct-reading pressure gauge to enter the pressure gauge landing cavity laterally;

[0018] The branch bridging box is located on a platform parallel to the axis of the cartridge body outside the cartridge body near the lower connector, and a steel pipe cable and an inner and outer electrical connection pipe of the cartridge are connected to the upper part of the platform, respectively;

[0019] The steel pipe cable passes through the cartridge body upwards, and is connected to the steel pipe cable of the direct-reading device at the wellhead on the ground at the upper end connection;

[0020] In the case of multi-layer section monitoring, the lower part of the branch bridging box is also connected with a steel pipe cable, and is connected to the branch bridging box or other downhole testing instrument equipment on the lower cartridge body at the lower end connection; the so-called multi-layer section monitoring is the case of more than one cartridge 1, and multiple direct-reading pressure gauges monitor multiple testing sections simultaneously. Figure 18 Corresponding single testing section is that only one direct-reading pressure gauge monitors one testing section in the well.

[0021] Characterized in that:

[0022] The lower part of the pressure gauge landing cavity of the cartridge body is provided with an electromagnetic coupling seat, which is a pair of completely identical and symmetrical structures with respect to the plane M;

[0023] The pair of symmetrical structures each include an electromagnetic coupling seat peek coil package and an electromagnetic coupling seat magnetically conductive body which are coaxially and tightly sleeved with each other, the electromagnetic coupling seat peek coil package is outside, and the electromagnetic coupling seat magnetically conductive body serves as a magnetically conductive core inside; the electromagnetic coupling seat peek coil package is internally provided with an electromagnetic coupling seat coil, and the axial direction of the coil is perpendicular to the plane M;

[0024] From the normal direction of the plane M, the electromagnetic coupling seat peek coil package has the same profile as the corresponding direction of the electromagnetic coupling head peek coil package, and the electromagnetic coupling seat magnetically conductive body has the same profile as the corresponding direction of the electromagnetic coupling head magnetically conductive body;

[0025] From the normal direction of the plane M, the electromagnetic coupling seat peek coil package has the same profile as the corresponding direction of the electromagnetic coupling head peek coil package, and the electromagnetic coupling seat magnetically conductive body has the same profile as the corresponding direction of the electromagnetic coupling head magnetically conductive body;

[0026] The two electromagnetic coupling seat peek coil packages of the pair of symmetrical structures are respectively connected to electromagnetic coupling seat connecting cables, which are connected to the branch bridge box through the outer electric connection tube of the outer sealing insulation of the barrel, and are connected to the steel pipe cable in the branch bridge box directly or through a bridge circuit;

[0027] Each of the pair of symmetrical structures protrudes inward at the lower part of the pressure gauge running cavity, and a slope is arranged between the protruding upper end and the inner wall of the pressure gauge running cavity, so that the electromagnetic coupling head at the lower end of the direct reading pressure gauge is inserted into the space between the pair of symmetrical structures.

[0028] Further, the barrel is characterized in that the distance between the two planes N is at least 0.2 mm larger than the distance between the two straight edges in the cross section of the aforementioned long and flat body.

[0029] Further, the barrel is characterized in that the electromagnetic coupling seat magnetic conductor comprises ferrite or silicon steel sheet or silicon steel sheet.

[0030] Further, the barrel is characterized in that a sewage discharge channel is arranged between the lower end of the pressure gauge running cavity and the full-bore central hole.

[0031] Further, the barrel is characterized in that the electromagnetic coupling seat peek coil package is integrally formed by pressure casting the coil and the peek material.

[0032] As described above, the removable direct reading pressure gauge and the barrel thereof have the following beneficial effects:

[0033] The technical scheme provided by the present application changes the direct connection mode of the original direct reading pressure gauge, which is fixedly connected with the steel pipe cable through direct electrical connection. The separable electromagnetic coupling mode can ensure power supply and data transmission of the direct reading pressure gauge, and can ensure sealing and electrical insulation, and can be used for steel wire operation for deployment and recovery, thereby overcoming the problem that the direct reading pressure gauge needs to be replaced by shutting down the well and pulling down all production pipe columns. At the same time, due to the use of the two-side clamping type electromagnetic coupling structure composed of the pair of symmetrical structures, the required radial space of the pressure gauge barrel is maximized, the overall outer diameter of the pressure gauge barrel is the same as that of the conventional barrel of the same specification, and the pressure gauge barrel can be normally applied in the currently used casing. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a three-dimensional schematic diagram of the overall appearance of one of the embodiments of the present application.

[0035] Figure 2 is a partial cutaway structure schematic diagram of the embodiment of the present application without the direct reading pressure gauge.

[0036] Figure 3 is a perspective view of the retrievable direct reading pressure gauge.

[0037] Figure 4 is a partial cutaway view of the direct reading pressure gauge in place.

[0038] Figure 5 is a front view of the retrievable direct reading pressure gauge in place on the upper part of the cavity 104.

[0039] Figure 6 is a bottom view of the Figure 5

[0040] Figure 7 is a cross-sectional view of the A-A plane of the Figure 5

[0041] Figure 8 is a cross-sectional view of the B-B plane of the Figure 7

[0042] Figure 9 is a partial enlarged view of the X area in the Figure 7

[0043] Figure 10 is a partial enlarged view of the Y area in the Figure 8

[0044] Figure 11 is a front view of the retrievable pressure gauge.

[0045] Figure 12 is a side view of the Figure 11

[0046] Figure 13 is a cross-sectional view of the C-C plane of the Figure 11

[0047] Figure 14 is a cutaway view of the retrievable direct reading pressure gauge in place on the upper part of the cavity 104.

[0048] Figure 15 is a cross-sectional view of the B-B plane of the Figure 14

[0049] Figure 16 is a partial enlarged view of the X area in the Figure 14

[0050] Figure 17 is a partial enlarged view of the Y area in the Figure 15

[0051] Figure 18 is a schematic diagram of the principle of the conventional direct reading pressure gauge monitoring system

[0052] ​​​​​​​​​​In the diagram: 1. Support body; 101. Upper connector of the support; 102. Lower connector of the support; 103. Full-bore center hole of the support; 104. Lower inlet cavity of the pressure gauge; 105. Drainage channel; 2. Electromagnetic coupling seat of the support; 201. PEEK coil package of the electromagnetic coupling seat; 202. Magnetic conductor of the electromagnetic coupling seat; 3. Direct reading pressure gauge; 4. Long flat body; 401. PEEK coil package of the electromagnetic coupling head; 402. Magnetic conductor of the electromagnetic coupling head; 403. Coil of the electromagnetic coupling head; 5. Inner and outer electrical connection pipes of the support; 501. Connecting cable of the electromagnetic coupling seat; 6. Branch bridging box; 7. Steel pipe cable; 701. Upper end connection of the steel pipe cable; 702. Lower end connection of the steel pipe cable; 8. Steel pipe cable fixing clip; 9. Oil pipe; 10. Casing; 11. Christmas tree; 12. Surface direct reading equipment. Detailed Implementation

[0053] The main technical solution proposed in this invention is to change the existing connection method between the direct-reading pressure gauge and the external steel pipe cable of the support. The existing direct fixed electrical connection is replaced with a detachable electromagnetic coupling connection. Simultaneously, a method is adopted where a pair of symmetrically constructed dual-coupling coils on both sides sandwich the pressure gauge's electromagnetic coupling head coil in the middle, maximizing the saving of radial space in the pressure gauge support while maintaining the same outer diameter as existing pressure gauge support of the same specifications.

[0054] Before introducing specific embodiments, it should be clarified that when describing parts, ends, and relative positions in this document and other documents of this application, the terms "up" and "down" refer to the spatial orientations such as those in the accompanying drawings, excluding those in the figures. Figure 13 The top and bottom views are shown in the front view, side view, sectional view, and enlarged partial view. The top and bottom relationships in the aforementioned views are consistent with the top and bottom relationships in actual use of the embodiments of the present invention.

[0055] The following is in conjunction with the appendix Figure 1 To the attached Figure 17 The specific structure and implementation method of one of the embodiments of the present invention will be described in detail.

[0056] The present invention discloses a removable direct-reading pressure gauge, the main feature of which is that it changes the existing connection method between the direct-reading pressure gauge and the external steel pipe cable of the support cylinder. The existing fixed direct electrical connection is changed to a detachable electromagnetic coupling connection. To achieve this connection, both the pressure gauge and the support cylinder structure must be modified accordingly.

[0057] First, there's the pressure gauge itself, such as... Figure 3As shown, the present application is characterized in that an electromagnetic coupling head is provided at the lower end of the direct-reading pressure gauge. The electromagnetic coupling head comprises a long flat body 4, the long axis of which is parallel to the axis of the direct-reading pressure gauge 3. The long flat body 4 has a constant cross-sectional shape along the axial direction, and the area of the cross-section is smaller than the cross-sectional area of the main body of the direct-reading pressure gauge 3. The cross-sectional shape of the long flat body 4 is quadrilateral: one pair of opposite sides are parallel and equal straight sides; the other pair of opposite sides are two equal arcs on the same circle, and the radius of the arcs is equal to the radius of the outer diameter of the main body of the direct-reading pressure gauge 3. The shape of the long flat body can also be understood as a cylinder with the same outer diameter as the direct-reading pressure gauge, from which two symmetrical circular segments are cut out in the longitudinal direction parallel to the two pairs of sides, as shown in Figure 3 and Figure 12 As shown, a long flat body with two mutually parallel planes is formed. The long flat body 4 contains an electromagnetic coupling head peek coil package 401 and an electromagnetic coupling head magnetic conductor 402, which are coaxially and tightly fitted with each other, the electromagnetic coupling head peek coil package 401 being on the outside and the electromagnetic coupling head magnetic conductor 402 being on the inside as a magnetic core, as shown in Figure 11 In this embodiment, as seen from the normal direction of the plane of the long flat body 4, the profiles of the electromagnetic coupling head peek coil package 401, the electromagnetic coupling head magnetic conductor 402, and the electromagnetic coupling head coil 403 are oblong. The whole forms a closed loop of the coil, with the center being the magnetic core electromagnetic coupling head magnetic conductor 402. The electromagnetic coupling head peek coil package 401 has the electromagnetic coupling head coil 403 inside, and the axial direction of the coil 403 is perpendicular to the axis of the direct-reading pressure gauge 3 and the straight sides of the cross-section of the long flat body 4; that is, perpendicular to the plane of the long flat body 4. In fact, the long flat body 4 with a constant cross-section has two opposite straight sides that form a pair of parallel planes, that is, the two planes of the long flat body 4.

[0058] To ensure the strength of the long flat body 4 to withstand the impact of the downhole environment and the launching and recovery operations, the electromagnetic coupling head peek coil package 401 and the electromagnetic coupling head coil 403 are made of peek material and are pressure-cast into an integral shape with the coil, and are then tightly bonded with the magnetic conductor, and finally inlaid and bonded into the corresponding space inside the long flat body 4. At the same time, the main body of the direct-reading pressure gauge 3 and the outside of the long flat body 4 are made of high-strength corrosion-resistant stainless steel, such as 17-4PH Chinese brand 0Cr17Ni4Cu4Nb used in this embodiment. The Chinese name of peek material is polyether ether ketone, which is a special engineering plastic with excellent properties such as high temperature resistance, self-lubrication, easy processing, and high mechanical strength.

[0059] The wound electromagnetic coupling head coil 403 has a coil wire tap for connecting with the functional circuit inside the direct-reading pressure gauge 3 to realize the corresponding functions.

[0060] To improve the electrical performance and mechanical strength of the electromagnetic coupling head flux guide 402 as a flux guide core, the electromagnetic coupling head flux guide 402 can be made of a material containing ferrite or all ferrite, or can be formed by stacking silicon steel sheets or silicon steel sheets.

[0061] To realize electromagnetic coupling with the above-mentioned direct-reading pressure gauge, the carrier cylinder for carrying the removable direct-reading pressure gauge also has a corresponding magnetic coupling structure. Therefore, in addition to the same structure as the existing pressure gauge carrier cylinder, it also includes a structure completely different from the existing pressure gauge carrier cylinder.

[0062] The same structure as the existing pressure gauge carrier cylinder includes a carrier cylinder body 1, an inner and outer electrical connection pipe 5, a branch bridge box 6, and a steel pipe cable 7. The carrier cylinder body 1 has an upper connector 101, a lower connector 102, a full-bore central hole 103, and a cylindrical pressure gauge running-in cavity 104. The upper connector 101 and the lower connector 102 are connected to the downhole tubing 9, respectively. The full-bore central hole 103 is used for normal production and operation, and the size of the bore directly affects the production and operation passing capacity of the entire tubing string. The principle is that the larger the better, close to the tubing diameter. The cylindrical pressure gauge running-in cavity 104 is used to accommodate and fix the pressure gauge. The inner and outer electrical connection pipe 5 is used to realize the electrical connection of the inner circuit of the carrier cylinder with the steel pipe cable 7 through the branch bridge box 6.

[0063] The axis of the full-bore central hole 103 and the axis of the pressure gauge running-in cavity 104 are usually parallel to each other, and the two axes have a common plane M. The plane M is proposed for more concise description later.

[0064] A passage is provided between the full-bore central hole 103 and the upper part of the pressure gauge running-in cavity 104, which allows the direct-reading pressure gauge 3 to enter the pressure gauge running-in cavity 104 laterally.

[0065] The branch bridge box 6 is located on a platform parallel to the axis of the carrier cylinder body 1 near the lower connector 102 on the outside of the carrier cylinder body 1, and the upper part is connected with the steel pipe cable 7 and the inner and outer electrical connection pipe 5, respectively. The inner and outer electrical connection pipe 5 is used to realize the electrical connection between the inside and outside of the carrier cylinder, while ensuring the sealing of the outside of the carrier cylinder and the insulation of the internal electrical circuit. The steel pipe cable 7 passes through the carrier cylinder body 1 upward, and the carrier cylinder body 1 has a through hole that can allow the steel pipe cable 7 to pass through, and the hole diameter is slightly larger than the steel pipe cable 7. The steel pipe cable 7 is connected at the upper end connection 701 and extends upward to the direct-reading device 12 at the wellhead ground surface. In the case of multi-layer section monitoring, the lower part of the branch bridge box 6 is also connected with the steel pipe cable 7, and is connected downward at the lower end connection 702 to the branch bridge box 6 or other downhole testing instrument equipment on the next carrier cylinder body 1.

[0066] In addition to the same structure as the existing pressure gauge carrier, in order to realize electromagnetic coupling with the direct reading pressure gauge, the technical scheme of the present application has the following different structures:

[0067] The lower part of the pressure gauge lower chamber 104 of the carrier body 1 is provided with an electromagnetic coupling seat, and the whole electromagnetic coupling seat is a pair of symmetrical structures 2 which are completely the same and symmetrical with the plane M; as shown in Figure 5 、 6 The two side double coupling coils can be coupled to the middle pressure gauge electromagnetic coupling head, realizing separable and close electromagnetic coupling. At the same time, the double coil clamping type electromagnetic coupling structure makes more use of the circumferential space in the carrier body 1 on both sides of the pressure gauge lower chamber 104, saving the radial space of the carrier body 1, thereby effectively reducing the overall outer diameter of the carrier body 1, so that the overall outer diameter of the carrier of the present application is the same as that of the existing direct reading pressure gauge carrier of the same specification. The outer diameter of the removable pressure gauge 3 in the embodiment is 1 inch, 25.4 mm; the full-bore central hole 103 is 60 mm, only 2 mm different from the inner diameter of the 2-7 / 8 inch oil pipe of the same specification; the outer diameter of the carrier used is 110 mm, which is the same size as the conventional pressure gauge carrier currently applied in the 5-1 / 2 inch casing, and can be normally applied in the 5-1 / 2 inch casing which is most commonly used in Daqing Oilfield.

[0068] Each of the pair of symmetrical structures 2 has a plane N parallel to the plane M in the direction facing the plane M. That is, each of the symmetrical structures 2 includes a plane N, and there are two planes N. The distance between the two planes N is greater than the distance between the two straight sides in the cross section of the long and flat body 4. The purpose is that the long and flat body 4 of the electromagnetic coupling head carried by the direct reading pressure gauge 3 can be inserted into this distance space to realize electromagnetic coupling.

[0069] Corresponding to the structure of the long and flat body 4 of the electromagnetic coupling head carried by the direct reading pressure gauge 3, each of the pair of symmetrical structures 2 includes an electromagnetic coupling seat peek coil package 201 and an electromagnetic coupling seat magnetic conductor 202 which are coaxially and closely fitted with each other, the electromagnetic coupling seat peek coil package 201 is outside, and the electromagnetic coupling seat magnetic conductor 202 is inside as a magnetic core; the electromagnetic coupling seat peek coil package 201 internally contains an electromagnetic coupling seat coil, and the axial direction of the coil is perpendicular to the plane M.

[0070] In order to closely couple with the electromagnetic coupling head of the direct reading pressure gauge, the electromagnetic coupling seat peek coil package 201 has the same profile as the electromagnetic coupling head peek coil package 401 in the corresponding direction from the normal direction of the plane M. The electromagnetic coupling seat magnetic conductor 202 also has the same profile as the electromagnetic coupling head magnetic conductor 402 in the corresponding direction. The corresponding direction refers to the normal direction of the plane of the long and flat body 4 of the direct reading pressure gauge.

[0071] Like the electromagnetic coupling head of the pressure gauge, the electromagnetic coupling seat peek coil package 201 and the electromagnetic coupling seat coil are made of peek material and are integrally formed by die casting with the wound coil. Then, the electromagnetic coupling seat magnetic conductor is tightly bonded together. Finally, it is inlaid and bonded to the corresponding shape space in the lower part of the pressure gauge lower cavity 104 inside the holder 1.

[0072] The wound coil of the electromagnetic coupling seat peek coil package 201 has a coil wire tap for linking the coil and the related circuit. In this embodiment, the two coil taps are connected to the steel pipe cable 7 in the branch bridge box 6 through the electromagnetic coupling seat connecting cable 501. The electromagnetic coupling seat coils inside the two electromagnetic coupling seat peek coil packages 201 of the pair of symmetric structures 2 are respectively connected to the electromagnetic coupling seat connecting cable 501. The electromagnetic coupling seat connecting cable 501 is connected to the branch bridge box 6 through the external sealing and insulation holder inner and outer electric connection pipe 5, and is directly connected to the steel pipe cable 7 in the branch bridge box 6 or connected to the steel pipe cable 7 through a bridge circuit. The holder inner and outer electric connection pipe 5 ensures the insulation of the internal circuit and the external sealing.

[0073] Since each of the pair of symmetric structures 2 protrudes inwardly at the lower part of the pressure gauge lower cavity 104, a slope is provided between the protruding upper end and the inner wall of the pressure gauge lower cavity 104, which facilitates the electromagnetic coupling head of the direct reading pressure gauge 3 to be smoothly inserted into the space between the pair of symmetric structures 2, i.e. the space between the two planes N. In order to ensure close electromagnetic coupling and smooth insertion into the space, the distance between the two planes N is at least 0.2 mm larger than the distance between the two straight edges in the cross section of the long and flat body 4.

[0074] Like the electromagnetic coupling head of the direct reading pressure gauge 3, in order to improve the electrical performance and mechanical strength of the electromagnetic coupling seat magnetic conductor 202 as a magnetic core, the electromagnetic coupling seat magnetic conductor 202 can be made of a material containing ferrite or all ferrite, or can be formed by stacking silicon steel sheets.

[0075] In order to prevent the lower end of the pressure gauge lower cavity 104 from accumulating dirt, which affects the direct reading pressure gauge to be in place, i.e. in position, a dirt discharge channel 105 is provided between the lower end of the pressure gauge lower cavity 104 and the full bore central hole 103. Dirt can be discharged at any time and cannot be accumulated.

[0076] The removable direct-reading pressure gauge 3 is deployed via tubing 9 using a dedicated wireline deployment tool, without interrupting well operations or production, and without requiring the tubing string to be pulled up or down. After the dedicated wireline deployment tool carries the removable direct-reading pressure gauge 3 into the full-bore center hole 103, a surface wireline operation is used to deflect the direct-reading pressure gauge 3. A channel is provided between the full-bore center hole 103 and the upper part of the pressure gauge lower entry chamber 104, allowing the direct-reading pressure gauge 3 to enter laterally into the pressure gauge lower entry chamber 104. Finally, the direct-reading pressure gauge 3 is lowered into the lower end of the pressure gauge lower entry chamber 104 within the support body 1, in the positioned state as shown. Figure 4 , 14 The positioning states are shown in figures 15, 16, and 17. At this point, the two opposing planes of the elongated flat body 4 are in contact with the two planes N of the electromagnetic coupling seat 2. The electromagnetic coupling seat PEek coil package 201 and the electromagnetic coupling head PEek coil package 401, as well as the electromagnetic coupling seat magnetic conductor 202 and the electromagnetic coupling head magnetic conductor 402, are completely overlapped, achieving tight electromagnetic coupling. Power supply and data transmission functions can be achieved with the surface direct-reading device 12 via the steel pipe cable 7. If the downhole retrievable direct-reading pressure gauge 3 malfunctions or needs to be retrieved for other reasons, a dedicated wire retrieval tool can be used to descend to the predetermined position, operate the wire retrieval tool to grasp the retrieval head at the top of the retrievable direct-reading pressure gauge 3, and retrieve it to the surface. Similarly, there is no need to shut down the well or stop production, nor to run out the tubing string. This solves the problem of existing technologies requiring well shutdown, production stoppage, and the running out of all tubing before replacing the pressure gauge.

Claims

1. A removable direct reading pressure gauge, characterized by: The lower end of the direct reading pressure gauge (3) is provided with an electromagnetic coupling head, which includes a long and flat body (4) parallel to the axis of the direct reading pressure gauge (3) and having a constant cross section and an area smaller than that of the main body of the direct reading pressure gauge (3); the cross section of the long and flat body (4) is quadrangular, one pair of opposite sides of which are parallel and equal, and the other pair of opposite sides are two equal arcs on the same circle, the radius of the arcs being equal to the radius of the outer diameter of the main body of the direct reading pressure gauge (3); the long and flat body (4) contains an electromagnetic coupling head peek coil package (401) and an electromagnetic coupling head magnet conductor (402) coaxially and tightly sleeved, the electromagnetic coupling head peek coil package (401) being outside and the electromagnetic coupling head magnet conductor (402) being inside as a magnet conductor core; the electromagnetic coupling head peek coil package (401) is provided with an electromagnetic coupling head coil (403) inside, the axis of the coil (403) being perpendicular to the axis of the direct reading pressure gauge (3) and the straight side of the cross section of the long and flat body (4); as viewed from the normal direction of the plane of the long and flat body (4), the profiles of the electromagnetic coupling head peek coil package (401), the electromagnetic coupling head magnet conductor (402) and the electromagnetic coupling head coil (403) are oblong; The electromagnetic coupling head peek coil package (401) and the electromagnetic coupling head coil (403) are made of peek material and are integrally formed by pressure casting, and are tightly bonded with the magnet conductor (402), and are finally embedded and bonded in the corresponding space in the long and flat body (4).

2. The removable direct reading pressure gauge of claim 1, wherein: The electromagnetic coupling head magnet conductor (402) is made of ferrite or silicon steel sheet or silicon steel sheet.

3. A cradle for holding the removable direct reading pressure gauge of claim 1 comprising: The support barrel body (1), the inner and outer electric connection pipe (5), the branch bridging box (6) and the steel pipe cable (7); The support barrel body (1) is provided with an upper connecting head (101), a lower connecting head (102), a full-bore central hole (103) and a cylindrical pressure gauge running-in cavity (104), and the upper connecting head (101) and the lower connecting head (102) are connected with the downhole tubing (9) respectively; The axes of the full-bore central hole (103) and the pressure gauge running-in cavity (104) are parallel to each other, and the common plane of the two axes is plane M; A passage is arranged between the full-bore central hole (103) and the upper part of the pressure gauge running-in cavity (104) to enable the direct reading pressure gauge (3) to enter the pressure gauge running-in cavity (104) laterally; The branch bridging box (6) is located on a platform parallel to the axis of the support barrel body (1) near the lower connecting head (102) on the outer side of the support barrel body (1), and is connected with the steel pipe cable (7) and the inner and outer electric connection pipe (5) respectively; The steel pipe cable (7) passes through the support barrel body (1) upwardly, and is connected with the steel pipe cable leading upwardly to the direct reading device (12) on the wellhead ground at the upper end connection (701); In the case of monitoring in a multilayer section, the lower part of the branch bridging box (6) is also connected with the steel pipe cable (7), and is connected with the branch bridging box (6) or other downhole testing instrument devices on the next support barrel body (1) downwardly at the lower end connection (702); The application is characterized in that: The electromagnetic coupling seat of the lower part of the pressure gauge lower chamber (104) of the barrel body (1) is provided with an electromagnetic coupling seat, which is a pair of completely identical and symmetrical structures (2) with the plane M; The pair of symmetrical structures (2) have a plane N parallel to the plane M in the direction facing the plane M, and the distance between the two planes N is greater than the distance between the two straight edges in the cross section of the long and flat body (4); Each of the pair of symmetrical structures (2) includes an electromagnetic coupling seat peek coil package (201) and an electromagnetic coupling seat magnetic conductor (202) coaxially and tightly sleeved with each other, the electromagnetic coupling seat peek coil package (201) is outside, and the electromagnetic coupling seat magnetic conductor (202) is inside as a magnetic core; the electromagnetic coupling seat peek coil package (201) is wrapped with an electromagnetic coupling seat coil, and the axis of the coil is perpendicular to the plane M; From the normal direction of the plane M, the electromagnetic coupling seat peek coil package (201) has the same profile as the corresponding direction of the electromagnetic coupling head peek coil package (401), and the electromagnetic coupling seat magnetic conductor (202) has the same profile as the corresponding direction of the electromagnetic coupling head magnetic conductor (402); The electromagnetic coupling seat coils inside the two electromagnetic coupling seat peek coil packages (201) of the pair of symmetrical structures (2) are respectively connected to the electromagnetic coupling seat connecting cable (501), the electromagnetic coupling seat connecting cable (501) passes through the barrel inner and outer electric connection pipe (5) which is sealed and insulated to connect to the branch bridge box (6), and is connected to the steel pipe cable (7) directly or through a bridge circuit in the branch bridge box (6); Each of the pair of symmetrical structures (2) protrudes inward at the lower part of the pressure gauge lower chamber (104), and a slope is arranged between the upper end of the protrusion and the inner wall of the pressure gauge lower chamber (104) to facilitate the insertion of the electromagnetic coupling head on the lower end of the direct reading pressure gauge (3) into the space between the pair of symmetrical structures (2).

4. The tray of claim 3, wherein: The distance between the two planes N is at least 0.2 mm greater than the distance between the two straight edges in the cross section of the long and flat body (4).

5. The tray of claim 3, wherein: The electromagnetic coupling seat magnetic conductor (202) includes ferrite or silicon steel sheet or silicon steel sheet.

6. The tray of claim 3, wherein: A sewage passage (105) is arranged between the lower end of the pressure gauge lower chamber (104) and the full bore central hole (103).

7. The tray of claim 3, wherein: The electromagnetic coupling seat peek coil package (201) is made of peek material and a wound coil.

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