Array of inductive coils

Abstract

The application provides an array induction coil system, comprising: a shell; a core rod arranged in the shell; a middle joint assembly connected with one end of the shell; a pressure balance assembly connected with the other end of the shell; and a coil assembly arranged on the outer periphery of the core rod; wherein the pressure balance assembly can balance the oil pressure in the inner cavity of the shell to prevent the oil pressure from damaging the shell. According to the technical scheme of the application, the pressure balance assembly is arranged to balance the oil pressure in the inner cavity of the shell, so that the oil pressure in the inner cavity of the shell is equal to the pressure of the mud in the outer wellbore. When the oil pressure in the inner cavity of the shell is too large, the pressure balance assembly can reduce the pressure in the inner cavity to be equal to the pressure of the mud in the outer wellbore. Thus, the problem that the shell is broken or deformed due to the volume expansion of the silicone oil and is finally damaged is avoided. Further, the array induction coil system can be normally used.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration and development technology, and in particular to an array induction coil system. Background Technology

[0002] Currently, array induction coil systems are used in induction logging instruments. Typically, the inner cavity of the outer casing of an array induction coil system is filled with dimethyl silicone oil. During logging, as the well temperature and pressure increase, the silicone oil expands, causing the oil pressure inside the outer casing to rise.

[0003] However, in related technologies, the array induction coil system is limited by its own structure, and there is a situation where the oil pressure inside is not reduced in time, which can easily lead to damage to its outer casing.

[0004] In other words, the array induction coil system in the relevant technology has the problem of silicone oil volume expansion causing damage to its outer casing. Summary of the Invention

[0005] To address the problems in the prior art, this application proposes an array induction coil system that solves the problem of silicone oil volume expansion causing damage to its outer casing.

[0006] The array induction coil system of the present invention includes: a housing; a core rod disposed within the housing; a connector assembly connected to one end of the housing; a pressure balancing assembly connected to the other end of the housing; and a coil assembly disposed on the outer periphery of the core rod; wherein the pressure balancing assembly is capable of balancing the oil pressure within the inner cavity of the housing to prevent the oil pressure from damaging the housing.

[0007] In one embodiment, the pressure balancing assembly includes: a housing connected to the other end of an outer casing, and a flow-through hole on the housing communicating with the inner cavity of the outer wellbore; and a piston slidably disposed within the housing. When the oil pressure inside the inner cavity of the outer casing increases, the piston slides in a first direction to reduce the oil pressure until the oil pressure inside the inner cavity of the outer casing is balanced with the pressure inside the inner cavity of the wellbore. In this embodiment, by setting up a piston, the reciprocating movement of the piston in the first direction balances the oil pressure inside the inner cavity of the outer casing and the pressure of the mud inside the outer wellbore. Thus, when the temperature inside the inner cavity of the outer casing is too high, the silicone oil volume expands, causing the oil pressure inside the inner cavity to increase. The piston moves to the right to increase the volume of the inner cavity of the outer casing, thereby reducing the pressure inside and making it equal to the pressure of the mud inside the outer wellbore. This avoids the problem of the outer casing cracking or deforming due to the expansion of the silicone oil volume, ultimately leading to its damage. This ensures the normal operation of the array induction coil system.

[0008] In one embodiment, the coil assembly includes: a coil positioning mechanism fixed to the outer periphery of a mandrel; and a functional coil fixed to the coil positioning mechanism. In this embodiment, the coil positioning mechanism can adjust and fix the axial position of the functional coil on the mandrel. This ensures that the functional coil can be accurately installed in a preset mounting position, thereby ensuring the normal operation of the array induction coil system.

[0009] In one embodiment, an external thread is provided on the outer periphery of the core rod, and the coil positioning mechanism includes: a ceramic skeleton disposed on the outer periphery of the core rod; a first adjusting member threadedly connected to the core rod; and a second adjusting member threadedly connected to the core rod; wherein the ceramic skeleton is located between the first adjusting member and the second adjusting member, and the functional coil is wound and fixed on the ceramic skeleton, and the axial position of the ceramic skeleton on the core rod can be limited by screwing the first adjusting member and the second adjusting member.

[0010] In one embodiment, the coil positioning mechanism further includes elastic elements, which are respectively disposed between the first adjusting element and the ceramic frame, and between the second adjusting element and the ceramic frame. With this embodiment, the axial position of the ceramic frame and its functional coil on the core rod can be adjusted by rotating the first and second adjusting elements. This adjustment method is convenient to operate and has high positioning accuracy. It greatly ensures the positional accuracy of the coil on the core rod, significantly reduces the difficulty of machining, improves assembly efficiency, and reduces the workload of assembly and electrical personnel.

[0011] In one embodiment, a first positioning hole is provided on the outer periphery of the core rod, a first adjusting member is provided with a first threaded hole, and the coil positioning mechanism further includes a first threaded connector, which is threadedly connected to the first threaded hole, with one end of the connector extending out of the first threaded hole and inserted into the first positioning hole. Through this embodiment, by using the positioning hole, the threaded hole, and the threaded connector, and by threading the connector into the positioning hole, the threaded connector is inserted into the positioning hole. This achieves precise positioning of the ceramic skeleton and the functional coil wound on it, thus meeting the high-precision positioning requirements of the functional coil.

[0012] In one embodiment, a second positioning hole is provided on the outer periphery of the core rod, a second adjusting member is provided with a second threaded hole, and the coil positioning mechanism further includes a second threaded connector, which is threadedly connected to the second threaded hole, with one end of the connector extending out of the threaded hole and inserted into the second positioning hole. Through this embodiment, by using the positioning hole, the threaded hole, and the threaded connector, and by threading the connector into the positioning hole, the threaded connector is inserted into the positioning hole. This achieves precise positioning of the ceramic skeleton and the functional coil wound on it, thus meeting the high-precision positioning requirements of the functional coil.

[0013] In one embodiment, a groove is provided on the outer periphery of the mandrel, located below the ceramic skeleton. The array induction coil system also includes a temperature sensor disposed within the groove. This embodiment uses the temperature sensor to measure the temperature at the coil location. By using multiple temperature readings, temperature compensation can be performed on the array induction coil system and the signal circuit, reducing the impact of temperature on the measurement structure and improving measurement accuracy.

[0014] In one embodiment, the functional coil includes a receiving coil, a shielding coil, and a transmitting coil, wherein the shielding coil is spaced between the receiving coil and the transmitting coil.

[0015] In one embodiment, an adapter is also included, which is connected to the other end of the housing.

[0016] The above-mentioned technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0017] The array induction coil system provided by the present invention has at least the following advantages compared with the prior art:

[0018] The system is equipped with a pressure balancing component to balance the oil pressure inside the housing, ensuring that the oil pressure inside the housing is equal to the mud pressure in the external wellbore. This allows the pressure balancing component to reduce the pressure inside the housing when it becomes too high, bringing it equal to the mud pressure in the external wellbore. This prevents the housing from cracking or deforming due to the expansion of the silicone oil, thus ensuring the proper functioning of the array induction coil system. Attached Figure Description

[0019] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0020] Figure 1 A schematic diagram of the array induction coil system of the present invention is shown;

[0021] Figure 2 Showing Figure 1 A magnified view of a portion of the array induction coil system at point A;

[0022] Figure 3 Showing Figure 2 A partial sectional view of another axial section of the array induction coil system;

[0023] Figure 4 A partial cross-sectional view of a comparative array induction coil system of the present invention is shown;

[0024] Figure 5The diagram shows the arrangement of the functional coils in an array induction coil system in the related art.

[0025] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0026] Figure label:

[0027] 10. Outer shell; 20. Core rod; 21. Wire groove; 30. Middle connector assembly; 40. Pressure balance assembly; 41. Housing; 411. Flow hole; 42. Piston; 43. Lower connector; 50. Coil assembly; 51. Coil positioning mechanism; 511. Ceramic skeleton; 512. First adjusting component; 513. Second adjusting component; 514. Elastic component; 515. First threaded connector; 516. Second threaded connector; 52. Functional coil; 60. Temperature sensor; 70. Adapter; 51'. Coil positioning mechanism; 511'. First positioning mechanism; 5111'. Bushing; 5112'. First adjusting nut; 5113'. First bushing screw; 5114'. Ceramic skeleton; 512'. Second positioning mechanism; 5121'. Skeleton screw; 5122'. Ceramic skeleton. Detailed Implementation

[0028] The invention will now be further described with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the present invention provides an array induction coil system, which includes a housing 10, a core rod 20, a connector assembly 30, a pressure balancing assembly 40, and a coil assembly 50. The core rod 20 is disposed inside the housing 10, the connector assembly 30 is connected to one end of the housing 10, the pressure balancing assembly 40 is connected to the other end of the housing 10, and the coil assembly 50 is disposed on the outer periphery of the core rod 20. The pressure balancing assembly 40 can balance the oil pressure inside the housing 10 to prevent oil pressure from damaging the housing 10.

[0030] In the above configuration, a pressure balancing component 40 is provided to balance the oil pressure inside the housing 10, ensuring that the oil pressure inside the housing 10 is equal to the pressure of the mud in the external wellbore. This way, when the oil pressure inside the housing 10 is too high, the pressure balancing component 40 can reduce the pressure inside, making it equal to the pressure of the mud in the external wellbore. This avoids the problem of the housing 10 cracking or deforming due to the volume expansion of the silicone oil, ultimately preventing damage. Furthermore, it ensures the normal operation of the array induction coil system.

[0031] It should be noted that the inner cavity of the outer casing 10 is generally filled with dimethyl silicone oil. During well logging, as the well temperature and pressure continuously increase, the silicone oil expands, causing the oil pressure inside the outer casing 10 to rise. If the oil pressure is not reduced in time, the outer casing 10 may burst or be damaged.

[0032] Specifically, in one embodiment, the outer shell 10 and the core rod 20 are made of fiberglass.

[0033] Specifically, such as Figure 1 As shown, in one embodiment, the pressure balancing assembly 40 includes a housing 41 and a piston 42. The housing 41 is connected to the other end of the outer casing 10, and a flow-through hole 411 is provided on the housing 41, communicating with the inner cavity of the outer wellbore. The piston 42 is slidably disposed within the housing 41. When the oil pressure inside the inner cavity of the outer casing 10 increases, the piston 42 slides in a first direction to reduce the oil pressure until the oil pressure inside the inner cavity of the outer casing 10 is balanced with the pressure inside the inner cavity of the wellbore.

[0034] In the above configuration, the piston 42, through its reciprocating movement in the first direction, balances the oil pressure inside the housing 10 and the mud pressure in the external wellbore. When the temperature inside the housing 10 becomes too high, the silicone oil expands, causing the oil pressure inside the housing 10 to rise. The piston 42 then moves to the right, increasing the volume of the housing 10's inner cavity, thereby reducing the pressure and bringing it equal to the pressure of the mud in the external wellbore. This avoids the problem of the housing 10 cracking or deforming due to silicone oil expansion, ultimately preventing its damage. This, in turn, ensures the normal operation of the array induction coil system.

[0035] Specifically, such as Figure 1 As shown, in one embodiment, the pressure balancing assembly 40 further includes a lower connector 43 disposed within the housing 41.

[0036] Specifically, such as Figure 2 and Figure 3 As shown, in one embodiment, the coil assembly 50 includes a coil positioning mechanism 51 and a functional coil 52. The coil positioning mechanism 51 is fixed to the outer periphery of the core rod 20, and the functional coil 52 is fixed to the coil positioning mechanism 51.

[0037] In the above configuration, the coil positioning mechanism 51 can adjust the axial position of the functional coil 52 on the core rod 20 and precisely fix it in that axial position. This ensures that the functional coil 52 can be accurately installed in the preset installation position, thereby ensuring that the array induction coil system can operate normally.

[0038] Specifically, such as Figure 2 and Figure 3As shown, in one embodiment, the outer periphery of the core rod 20 is provided with external threads, and the coil positioning mechanism 51 includes a ceramic skeleton 511, a first adjusting member 512, and a second adjusting member 513. The ceramic skeleton 511 is disposed on the outer periphery of the core rod 20, the first adjusting member 512 is threadedly connected to the core rod 20, and the second adjusting member 513 is threadedly connected to the core rod 20. The ceramic skeleton 511 is located between the first adjusting member 512 and the second adjusting member 513, and the functional coil 52 is wound and fixed on the ceramic skeleton 511. By screwing the first adjusting member 512 and the second adjusting member 513, the axial position of the ceramic skeleton 511 on the core rod 20 can be defined.

[0039] Specifically, in one embodiment, the ceramic skeleton 511 is made of ceramic material.

[0040] Specifically, such as Figure 2 and Figure 3 As shown, in one embodiment, the coil positioning mechanism 51 further includes an elastic element 514, which is respectively disposed between the first adjusting element 512 and the ceramic skeleton 511, and between the second adjusting element 513 and the ceramic skeleton 511.

[0041] It should be noted that the elastic element 514 is provided to compensate for the gap caused by the difference in thermal expansion coefficients between the two adjusting elements (i.e., the first adjusting element 512 and the second adjusting element 513) when the coil system is at high temperature, due to the difference in thermal expansion coefficients between the fiberglass material and the ceramic material (i.e., the difference in thermal expansion coefficients between the ceramic skeleton 511 and the core rod 20). The gap is caused by the distance between the two adjusting elements (i.e., the first adjusting element 512 and the second adjusting element 513) being greater than the length of the ceramic skeleton 511.

[0042] Specifically, in one embodiment, both the first adjusting member 512 and the second adjusting member 513 are adjusting nuts.

[0043] In the above configuration, the axial position of the ceramic skeleton 511 and its functional coil 52 on the core rod 20 can be adjusted by turning the first adjusting member 512 and the second adjusting member 513. This adjustment method is convenient to operate and has high positioning accuracy (using threaded positioning). It greatly ensures the positional accuracy of the coil on the core rod, significantly reduces the difficulty of machining, improves assembly efficiency, and reduces the pressure on assembly and electrical personnel.

[0044] Specifically, in one embodiment, the elastic element 514 is a rubber pad.

[0045] Specifically, such as Figure 2 and Figure 3As shown, in one embodiment, a first matching positioning hole is provided on the outer periphery of the core rod 20, a first adjusting member 512 is provided with a first matching threaded hole, and the coil positioning mechanism 51 further includes a first threaded connector 515, which is threadedly connected to the first matching threaded hole, with one end of the connector protruding from the first matching threaded hole passing through the first matching positioning hole.

[0046] Specifically, such as Figure 2 and Figure 3 As shown, in one embodiment, a second matching positioning hole is provided on the outer periphery of the core rod 20, a second adjusting member 513 is provided with a second matching threaded hole, and the coil positioning mechanism 51 further includes a second threaded connector 516, which is threadedly connected to the second matching threaded hole, with one end of the connector protruding from the second matching threaded hole passing through the second matching positioning hole.

[0047] In the above configuration, a positioning hole, a matching threaded hole, and a threaded connector are used, with the threaded connector threaded into the matching threaded hole and inserted into the positioning hole. This achieves precise positioning of the ceramic frame 511 and the functional coil 52 wound on it, thus meeting the high-precision positioning requirements of the functional coil 52.

[0048] Specifically, such as Figure 3 As shown, in one embodiment, a groove 21 is provided on the outer periphery of the core rod 20. The groove 21 is located below the ceramic skeleton 511. The array induction coil system also includes a temperature sensor 60, which is disposed in the groove 21.

[0049] In the above settings, the temperature sensor 60 is set to measure the temperature value at the location of the coil. By using multiple temperature values, temperature compensation can be performed on the array induction coil system and signal circuit, reducing the impact of temperature on the measurement structure and improving measurement accuracy.

[0050] Specifically, such as Figure 1 As shown, in one embodiment, the functional coil 52 includes a receiving coil, a shielding coil, and a transmitting coil, wherein the shielding coil is spaced between the receiving coil and the transmitting coil.

[0051] In the above configuration, the coil is wound on a ceramic frame 511 with a low coefficient of thermal expansion, ensuring high stability of the coil's electrical parameters. This ensures that the array induction coil system has good performance.

[0052] It should be noted that the coil positioning mechanism 51 in this application is applicable to the positioning of receiving coils, shielding coils, and transmitting coils. Compared with related technologies, which use various structures for different coils, it has strong compatibility.

[0053] Specifically, such as Figure 1As shown, in one embodiment, the array induction coil system further includes an adapter 70, which is connected to the other end of the housing 10.

[0054] The following is combined with Figures 1 to 3 Here is a complete embodiment of this application:

[0055] This invention relates to an array induction coil system for high temperature and high pressure applications. The array induction coil system includes a central connector assembly 30, a fiberglass shell (shell 10), a fiberglass core rod (core rod 20), a receiving coil, a shielding coil, a transmitting coil, a lower connector 43 (located inside the shell 41), a pressure balancing shell (shell 41), a piston 42, an adapter 70, an adjusting screw, a rubber pad, a ceramic frame 511, a set screw (first threaded connector 515 and second threaded connector 516), and a temperature sensor 60.

[0056] Specifically, the intermediate connector assembly 30, the fiberglass shell, the pressure balance shell, and the piston 42 form a sealed cavity filled with dimethyl silicone oil.

[0057] Specifically, the lower end of the pressure balance shell is designed with a waist-shaped hole (flow hole 411), through which downhole mud can enter the right side of piston 42, so that the oil chamber pressure can be linked with the pressure balance shell (mud pressure) to form pressure balance.

[0058] Specifically, piston 42 can move left and right within the pressure balance housing.

[0059] Specifically, during well logging, as the well temperature and pressure continuously increase, the volume of the silicone oil expands, and piston 42 moves to the right. During well discharge, as the well temperature and pressure continuously decrease, piston 42 moves to the left. This ensures that the volume of the oil chamber changes with temperature and pressure, preventing the fiberglass shell from being burst or crushed by absolute pressure.

[0060] Specifically, the outer circumference of the fiberglass core rod is threaded, and each coil has two rubber pads and two adjusting nuts at both ends. The two rubber pads are used to compensate for the gap caused by the difference in thermal expansion coefficients between the fiberglass and ceramic materials at high temperatures, which results in the distance between the two adjusting nuts being greater than the length of the coil frame (ceramic frame 511). The two adjusting nuts are used to adjust the axial position of the coil. After the coil position is adjusted, tightening the two adjusting nuts at both ends of the coil frame will fix the coil position. Each adjusting nut has two set screw holes and two set screws for locking the adjusting nut position.

[0061] Specifically, the maximum clearance between the set screw and the corresponding locating hole is 0.12 mm. The set screw locating hole is... Set screw mating surfaces The fiberglass core rod has a thread pitch of 2mm, and one rotation can move the ceramic skeleton axially by 2mm. The circumferential rotation of the adjusting nut relative to the fiberglass core rod can achieve axial positioning of the ceramic skeleton 511 on the core rod 20. When the set screw is installed in place, the inner hole of the adjusting nut can rotate a certain arc length relative to the outer circle surface of the mandrel (since the maximum gap between the set screw and the matching positioning hole is 0.12mm), and the maximum rotation angle is calculated to be 0.0046 radians, corresponding to an axial movement of 0.0015mm of the ceramic skeleton 511 relative to the core rod 20. Therefore, after the set screw is installed, a positioning accuracy of 0.0015mm can be achieved for the ceramic skeleton 511, which meets the electrical performance requirements of the coil.

[0062] Specifically, a temperature sensor is evenly distributed under the slot 21 corresponding to each coil to measure the temperature value at each coil location. By collecting the system measurement results corresponding to the series of heating or cooling temperature points of the array induction coil system, the relationship between the measurement results and temperature changes can be determined. This allows for temperature compensation of the coil system and signal circuit, reducing the influence of temperature on the measurement results and improving measurement accuracy.

[0063] The following is a comparative example of this application:

[0064] A comparative example provides an array of induction coil systems. Its difference from the embodiments of this application lies in:

[0065] The structure of the coil positioning mechanism 51' is different from that of the coil positioning mechanism 51 in this application, but the other structures are the same as those in this application, and will not be described in detail here.

[0066] Specifically, such as Figure 4 As shown, the coil positioning mechanism 51' includes a first positioning mechanism 511' and a second positioning mechanism 512', wherein the first positioning mechanism 511' is used to fix the shielding coil, and the second positioning mechanism 512' is used to fix the transmitting coil or the receiving coil.

[0067] Specifically, such as Figure 4 As shown, the first positioning mechanism 511' includes a bushing 5111', a first adjusting nut 5112', a first bushing screw 5113', and a ceramic frame 5114'. The first bushing screw 5113' fixes the bushing 5111' to the outer circumference of the fiberglass core rod. The outer circumference of the bushing 5111' has external threads. The first adjusting nuts 5112' are respectively located at both ends of the ceramic frame 5114' and are threadedly connected to the bushing 5111'. Positioning of the ceramic frame 5114' and its shielding coil can be achieved by adjusting the positions of the two first adjusting nuts 5112'.

[0068] Specifically, such as Figure 4As shown, the second positioning mechanism 512' includes four skeleton screws 5121' (made of PEEK material), which radially fix the ceramic skeleton 5122' to the outer circumference of the fiberglass core rod. This achieves the fixation of the transmitting coil or receiving coil disposed thereon.

[0069] It should be noted that, in the comparative example, for the transmitting or receiving coils requiring a fixed position, PEEK material frame screws 5121' are used to fix them to the fiberglass core rod. For the shielded coil requiring an adjustable position, it is fitted onto the bushing 5111', and the two ends of the coil are fixed with first adjusting nuts 5112'. The bushing 5111' is fixed to the fiberglass core rod by PEEK material first bushing screws 5113'. The ceramic frame 5122' used for the transmitting or receiving coils is fixed to the fiberglass core rod by four frame screws 5121'. Because the coil system has extremely high requirements for coil position, the coil position must not move when exposed to high temperatures or vibration. Therefore, extremely high requirements are placed on the four optical holes on the ceramic frame 5122' used for the transmitting and receiving coils, and on the four screw holes on the fiberglass core rod. The tolerances are stringent, and the machining precision is extremely high. If the tolerances are even slightly large, the transmitting or receiving coil and the core rod cannot be completely fixed together, and the coil may move relative to the fiberglass core rod by about 0.1 mm, which is unacceptable. Similarly, extremely high requirements are placed on the optical holes on the bushing 5111' of the first positioning mechanism 511', and on the two screw holes on the fiberglass core rod. The tolerances are stringent, and the machining precision is extremely high. If the tolerances are even slightly large, the bushing 5111' and the fiberglass core rod cannot be completely fixed together, and the coil may move relative to the fiberglass core rod by about 0.1 mm, which is unacceptable. Controlling these tolerances inevitably increases the processing difficulty and cost.

[0070] However, in this embodiment, the coil is wound on a ceramic frame 511 with a low coefficient of thermal expansion, ensuring high stability of the coil's electrical parameters. The position of the ceramic frame 511 can be adjusted by adjusting the adjusting nuts on both sides of the coil frame. By changing the direction of displacement restriction on the mating parts by the set screw clearance from axial to circumferential, the positioning accuracy of the coil on the mandrel is extremely high, greatly reducing the difficulty of machining, improving assembly efficiency, and alleviating the pressure on assembly and electrical personnel. The multi-point temperature-compensated coil structure and circuit design can compensate for the temperature of the coil system and signal circuit, ensuring the accuracy, reliability, and repeatability of the instrument's measurements, and improving measurement precision.

[0071] It should be noted that, as Figure 5As shown, in related technologies, array induction coil systems typically employ a single-sided arrangement, with multiple arrays in total. Each array contains three coils: a transmitting coil, a main receiving coil, and a shielded receiving coil. The transmitting coil is shared by multiple arrays and is located at the bottom of the coil system. The core rod is typically made of fiberglass, and the coil frame is made of high-temperature resistant ceramic material (ceramic frame). Here, T represents the transmitting coil, B the shielded receiving coil, and R the main receiving coil.

[0072] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0073] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. An array induction coil system, characterized in that, include: shell; as well as The core rod is disposed within the outer casing; as well as A connector assembly is connected to one end of the housing; as well as A pressure balancing assembly is connected to the other end of the housing; as well as A coil assembly is disposed on the outer periphery of the core rod; The pressure balancing component can balance the oil pressure inside the housing cavity to prevent the oil pressure from damaging the housing. The pressure balancing assembly includes: A housing, connected to the other end of the outer casing, wherein the housing is provided with a flow passage that communicates with the inner cavity of the outer wellbore; and The piston is slidably disposed within the housing; When the oil pressure inside the outer casing increases, the piston slides in a first direction to reduce the oil pressure until the oil pressure inside the outer casing is balanced with the pressure inside the wellbore. The coil assembly includes: A coil positioning mechanism is fixed on the outer periphery of the core rod; and The functional coil is fixed on the coil positioning mechanism; The core rod has an external thread on its outer periphery, and the coil positioning mechanism includes: A ceramic skeleton is disposed on the outer periphery of the mandrel; and A first adjusting element is threadedly connected to the mandrel; and The second adjusting component is threadedly connected to the mandrel. The ceramic skeleton is located between the first and second adjusting members, and the functional coil is wound and fixed on the ceramic skeleton. The axial position of the ceramic skeleton on the mandrel can be limited by screwing the first and second adjusting members. The coil positioning mechanism further includes elastic elements, which are respectively disposed between the first adjusting element and the ceramic skeleton, and between the second adjusting element and the ceramic skeleton.

2. The array induction coil system according to claim 1, characterized in that, The core rod has a first matching positioning hole on its outer periphery, the first adjusting member has a first matching threaded hole, and the coil positioning mechanism also includes a first threaded connector. The first threaded connector is threadedly connected to the first matching threaded hole, and one end of the connector that passes through the first matching threaded hole is inserted into the first matching positioning hole.

3. The array induction coil system according to claim 1, characterized in that, The core rod is provided with a second matching positioning hole on its outer periphery, the second adjusting member is provided with a second matching threaded hole, and the coil positioning mechanism further includes a second threaded connector, which is threadedly connected to the second matching threaded hole, with one end of the connector passing through the second matching threaded hole and inserted into the second matching positioning hole.

4. The array induction coil system according to claim 1, characterized in that, A groove is provided on the outer periphery of the core rod, the groove being located below the ceramic skeleton. The array induction coil system also includes a temperature sensor, which is disposed within the groove.

5. The array induction coil system according to claim 1, characterized in that, The functional coil includes a receiving coil, a shielding coil, and a transmitting coil, wherein the shielding coil is spaced between the receiving coil and the transmitting coil.

6. The array induction coil system according to claim 1, characterized in that, It also includes an adapter that connects to the other end of the housing.

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