Logging cable releasable connecting device

Abstract

The invention relates to a logging cable releasable connecting device which comprises a cable head assembly, an instrument string assembly, a releasable module and a tension connecting assembly, a cable clamping cone assembly is installed in one end of an outer shell, and the instrument string assembly is installed at the other end of the outer shell; the tension connecting assembly comprises a connecting rod and a tension bar, the connecting rod is installed in the outer shell, and one end of the connecting rod is connected with the wire clamping cone set through a reducing sleeve. The releasable module is connected with the other end of the connecting rod through a connecting block, and is connected with the instrument string assembly through a pin assembly. According to the invention, the hot melting type autonomous release module is matched with the weak point connection of the tension rod, so that the cable is prevented from being snapped and damaged due to overlarge tension during separation, and the tension required to be applied to the cable can be reduced; the cable core contact pin assembly is arranged in the cable, the cable core is protected by filling high-temperature silicone grease, and the cable is suitable for high-temperature, high-pressure and changeable underground environments, so that the cable in a connected and separated state is effectively protected, and reliable connection and rapid and safe separation of the cable and an instrument string are met.

Description

Technical Field

[0001] This invention relates to the field of logging cable connection technology, and more specifically to a releasable logging cable connection device. Background Technology

[0002] Logging cables are often connected to downhole instruments via a bridle, allowing for separation of the cable from the instrument. However, most common connection devices employ a mechanical weak-point pull-out release method. Therefore, the strength of the internal release structure cannot be set too high, otherwise it will not be able to achieve release through pull-out and may even cause damage to the cable. On the other hand, if the strength of the release structure is set too low, the connection between the cable and the instrument will not be reliable enough. When the instrument encounters obstruction downhole, it will not be able to apply greater pulling force to release it, which may cause the instrument to fall into the well. Furthermore, the mechanical weak point is a one-time structure, and it takes a certain amount of time to break. After breaking, it needs to be replaced for the next use. Both the release and reassembly processes take time, affecting logging efficiency. Summary of the Invention

[0003] This invention provides a releasable connection device for logging cables, aiming to solve the problems in the prior art.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0005] A releasable connection device for a logging cable includes a cable head assembly, an instrument string assembly, a releasable module, and a tension connection assembly. The cable head assembly includes a clamping cone group and a housing, both ends of which are open. The clamping cone group is installed inside one end of the housing, and the instrument string assembly is installed at the other end of the housing.

[0006] The tension connection assembly includes a connecting rod and a tension bar. The connecting rod is installed inside the housing, with one end connected to the wire clamping cone assembly via an adapter sleeve. One end of the tension bar is connected to the other end of the connecting rod. The releasable module is installed inside the housing and is connected to the other end of the tension bar via a connecting block. The releasable module is also connected to the instrument string assembly via a pin assembly. The connecting block is fixedly connected to the housing.

[0007] The beneficial effects of this invention are: by connecting the cable and the instrument string through the releasable module, the cable can be actively released in conjunction with the cable tension, thereby achieving separation of the cable and the instrument string with less tension, thus better protecting the cable; at the same time, by connecting the cable and the releasable module through the tension connection assembly, the tension bar's tension weakness can be utilized to break the tension bar when the releasable module fails to release normally, thus avoiding excessive tension on the cable surface, thereby further protecting the cable.

[0008] This invention uses a self-release module in conjunction with a tension bar to address weak points, preventing the cable from being pulled apart by excessive tension during separation and reducing the required tension on the cable. This ensures reliable connection and rapid, safe separation between the cable and the instrument string.

[0009] Based on the above technical solution, the present invention can be further improved as follows.

[0010] Furthermore, the clamping cone assembly includes a cone frame, a large cone, and a small cone. The cone frame, the large cone, and the small cone are respectively installed inside the outer shell and are coaxially sleeved from the outside to the inside. The large cone and the small cone are respectively conical in shape, and the small cone has a through central hole for the cable core to pass through. One end of the adapter sleeve is fixedly sleeved outside the cone frame.

[0011] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. The inner and outer steel wires of the cable are clamped by a multi-layer cone structure, which ensures the tight connection between the clamping cone group and the outer armor of the cable and avoids pulling off and damaging the cable core when the cable is pulled up.

[0012] Furthermore, the outer layer steel wires of the cable are evenly arranged between the cone frame and the large cone, and the inner layer steel wires of the cable are evenly arranged between the large cone and the small cone.

[0013] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. The inner and outer steel wires of the cable are clamped by a multi-layer cone structure, which ensures the tight connection between the clamping cone group and the outer armor of the cable and avoids pulling off and damaging the cable core when the cable is pulled up.

[0014] Furthermore, a limiting plate is provided at one end of the connecting rod, and the limiting plate is locked into the groove at the other end of the adapter sleeve by a locking sleeve.

[0015] The advantages of adopting the above-mentioned further solution are that it has a simple structure, reasonable design, and convenient assembly by using a limit plate to realize the connection between corresponding components.

[0016] Furthermore, the releasable module includes a release elastomer and a release mechanism that are interlocked together. The release elastomer is connected to the tension bar via the connecting block. The release mechanism is connected to the instrument string assembly via a connecting cylinder, and the connecting cylinder is sleeved outside the release mechanism.

[0017] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. Under a certain tension applied to the cable, the release elastic body can be separated from the release mechanism, thereby realizing the separation of the cable from the instrument string.

[0018] Furthermore, the space between the clamping cone assembly, the tension connection assembly, the connecting cylinder, the pin assembly, and the outer casing is filled with high-temperature silicone grease; the outer casing is provided with silicone grease injection holes.

[0019] The advantages of adopting the above-mentioned further solution are that it has a simple structure and reasonable design. It uses the consistency of high-temperature silicone grease to fix the cable core to a certain extent, while forming a flexible buffer zone between the outer shell and the internal components. It can adapt to the variable pressure environment of downhole operations, and its high temperature resistance is strong. Its consistency is less affected by temperature changes, so it can adapt to variable temperature environments and achieve long-term operation under high temperature and high pressure. In addition, due to its fluidity, it can play a good role in protection, insulation and sealing when not released, ensuring reliable connection between the cable and the equipment. When released, it will not hinder the release action and can protect the exposed cable core during the process.

[0020] Furthermore, the limiting plate, the connecting block, and the connecting cylinder are provided with multiple wire passage grooves at uniform intervals in the circumferential direction.

[0021] The advantages of adopting the above-mentioned further scheme are that the structure is simple and the design is reasonable. The use of multiple pairs of cable slots facilitates the connection of the internal cable core through each cable slot to the pin assembly, so as to realize the electrical connection required for logging and release actions, thereby reducing the impact of tension on the cable core and achieving the function of protecting the cable core.

[0022] Furthermore, the tension bar has a structure that is thin at both ends and thick in the middle, and an annular groove is provided in the middle.

[0023] The beneficial effect of adopting the above-mentioned further solution is that the tension bar has a reasonable structural design and is easy to break when the cable is subjected to a certain tension, thereby allowing the cable head assembly to separate from the cable head assembly.

[0024] Furthermore, both the connecting rod and the connecting block are provided with a fitted square shaft at their opposite ends, and the two fitted square shafts are provided with threaded holes at their opposite ends; the two ends of the tension rod are respectively threadedly connected to the two threaded holes.

[0025] The advantages of adopting the above-mentioned further solution are that the structure is simple, the design is reasonable, and the tension bar is easy to assemble with other components.

[0026] Furthermore, the two sets of square shafts are fitted with connecting sleeves, one end of which is connected to the connecting block to fix the set of square shafts, and the other end of which is connected to the connecting rod to slide the set of square shafts; a limiting sleeve is installed between the opposite ends of the two sets of square shafts, and the limiting sleeve is fitted over the tension bar.

[0027] The beneficial effects of adopting the above-mentioned further solution are that the sleeve square shaft can constrain the relative rotation of the two ends of the tension bar, avoid the torque transmitted from the cable from affecting the weak points of the tension bar, thereby avoiding abnormal breakage of the tension bar and ensuring the safety and reliability of the connection; in addition, the limiting sleeve can constrain the distance between the connecting rod and the connecting block, so that the sleeve square shafts at both ends of the tension bar can be axially aligned, thereby facilitating the installation of the connecting sleeve. Attached Figure Description

[0028] Figure 1 This is an overall sectional view of the present invention;

[0029] Figure 2 This is a schematic diagram of the assembly structure of the tension connection component and the clamping cone group in this invention;

[0030] Figure 3 for Figure 2 A sectional view along the middle aa direction;

[0031] Figure 4 for Figure 2 A sectional view along the middle (bb) direction;

[0032] Figure 5 This is a schematic diagram of the releasable module in this invention.

[0033] The attached diagram lists the components represented by each number as follows:

[0034] 1. Cable head assembly; 11. Housing; 2. Instrument string assembly; 3. Release module; 31. Release elastomer; 32. Release mechanism; 33. Locking rod; 34. Heating module; 35. Limiting module; 36. Spring; 4. Tension connection assembly; 41. Connecting rod; 411. Limiting plate; 42. Adapter sleeve; 421. Locking sleeve; 43. Tension bar; 44. Connecting block; 45. Set square shaft; 46. Connecting sleeve; 47. Limiting sleeve; 48. Spring; 5. Connecting cylinder; 6. Pin assembly; 7. Wire clamping cone assembly; 71. Conical frame; 72. Large cone; 73. Small cone; 8. Wire guide groove. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Example 1

[0040] like Figures 1 to 5 As shown, this embodiment provides a releasable connection device for logging cables, including a cable head assembly 1, an instrument string assembly 2, a releasable module 3, and a tension connection assembly 4. The cable head assembly 1 includes a clamping cone group 7 and an outer shell 11, both ends of which are open. The clamping cone group 7 is installed inside one end of the outer shell 11, and the instrument string assembly 2 is installed at the other end of the outer shell 11.

[0041] The tension connection assembly 4 includes a connecting rod 41 and a tension bar 43. The connecting rod 41 is installed inside the outer shell 11, and one end of it is connected to the wire clamping cone assembly 7 via an adapter sleeve 42. One end of the tension bar 43 is connected to the other end of the connecting rod 41. The releasable module 3 is installed inside the outer shell 11 and is connected to the other end of the tension bar 43 via a connecting block 44. The releasable module 3 is also connected to the instrument string assembly 2 via a pin assembly. The connecting block 44 is fixedly connected to the outer shell 11.

[0042] This solution connects the cable and instrument string via a releasable module 3, which can actively release the cable in conjunction with the cable tension, thereby achieving separation of the cable and instrument string with less tension and thus better protecting the cable. At the same time, the cable and releasable module 3 are connected via a tension connection component 4. By utilizing the tension weakness of the tension bar 43, the tension bar 43 can be broken when the releasable module 3 fails to release normally, thus avoiding excessive tension on the cable surface and further protecting the cable.

[0043] Preferably, in this embodiment, a spring 48 is sleeved on one end of the adapter sleeve 42 near the outer shell 11 to protect the outer steel wire of the cable at the connection of the clamping cone group, so as to prevent the cable from being excessively deflected and twisted relative to the clamping cone group for a long time, which would cause the outer steel wire to break.

[0044] This embodiment uses a self-release module in conjunction with a tension bar to prevent the cable from being pulled apart by excessive tension during separation, thus reducing the required tension on the cable and ensuring reliable connection and rapid, safe separation between the cable and the instrument string.

[0045] Example 2

[0046] Based on Embodiment 1, in this embodiment, the clamping cone assembly 7 includes a cone frame 71, a large cone 72, and a small cone 73. The cone frame 71, the large cone 72, and the small cone 73 are respectively installed inside the outer casing 11, and are coaxially sleeved from the outside to the inside. The large cone 72 and the small cone 73 are respectively conical in shape, and the small cone 73 is provided with a through central hole for the cable core to pass through. One end of the adapter sleeve 42 is fixedly sleeved on the outside of the cone frame 71.

[0047] The solution has a simple structure and a reasonable design. It uses a multi-layered cone structure to clamp the inner and outer steel wires of the cable, ensuring a tight connection between the clamping cone assembly and the cable armor, and preventing the cable core from being pulled off and damaged when the cable is lifted.

[0048] Example 3

[0049] Based on Embodiment 2, in this embodiment, the outer steel wires of the cable are evenly arranged between the cone frame 71 and the large cone 72, and the inner steel wires of the cable are evenly arranged between the large cone 72 and the small cone 73.

[0050] The solution has a simple structure and a reasonable design. It uses a multi-layered cone structure to clamp the inner and outer steel wires of the cable, ensuring a tight connection between the clamping cone assembly and the cable armor, and preventing the cable core from being pulled off and damaged when the cable is lifted.

[0051] Example 4

[0052] Based on any one of Embodiments 2 to 3, in this embodiment, a limiting plate 411 is provided at one end of the connecting rod 41, and the limiting plate 411 is locked into the groove at the other end of the adapter sleeve 42 by a locking sleeve 421.

[0053] The solution has a simple structure and reasonable design. It uses a limit plate to connect the corresponding components, making assembly convenient.

[0054] Based on the above scheme, the locking sleeve 421 has a structure that is thick at one end and thin at the other end, and both ends are open; the locking sleeve 421 is sleeved on the connecting rod 41, and the other end of the adapter sleeve 42 has an internal thread. The thick end of the locking sleeve 421 is connected to the adapter sleeve 42 through the thread, locking the limiting plate 411 in the groove at one end of the adapter sleeve 42.

[0055] Example 5

[0056] Based on Embodiment 4, in this embodiment, the releasable module 3 includes a release elastomer 31 and a release mechanism 32 that are interlocked together. The release elastomer 31 is connected to the tension rod 43 through the connecting block 44. The release mechanism 32 is connected to the instrument string assembly 2 through the connecting cylinder 5, and the connecting cylinder 5 is sleeved on the outside of the release mechanism 32.

[0057] Preferably, in this embodiment, the release mechanism 32 is provided with an end hole for the release elastic body 31 to be inserted. The release elastic body 31 is inserted into the end hole, which has a cavity with both ends open. An annular boss is provided in the end hole, and an annular groove is provided on the outer side of the release elastic body 31. The annular boss and the annular groove are fitted together to restrict the axial sliding of the elastic release body. One end of the locking rod 33 is inserted into the release elastic body 31 and can slide along the axial direction of the release mechanism 32. The heating module 34 is installed in the release mechanism 32, and the other end of the locking rod 33 has a cavity. One end of the heating module 34 extends into the cavity. The limiting module 35 is fixedly sleeved on the heating module 34 and abuts against the other end of the locking rod 33. The locking rod 33 has a step, and a spring 36 is sleeved on the locking rod 33. The two ends of the spring 36 abut against the step and the annular protrusion in the release mechanism 32, respectively.

[0058] Furthermore, the limiting module 35 adopts a thermoplastic material structure and is sleeved on the outside of the heating module 34. That is, the release device uses a thermoplastic release structure. The heating module 34 heats the limiting module 35, causing it to melt, thereby releasing the axial movement constraint on the locking rod 33. A preset elastic reset element, i.e., spring 36, pushes the locking rod 33 axially away from the release elastic body 31, causing the release elastic body 31 to release its tight contact with the inner wall of the end hole. Under a certain tensile force applied by the cable, the release elastic body can then detach from the release device, thus separating the cable from the instrument string. Simultaneously, the heating module 34 can heat and melt the high-temperature silicone grease near the outside of the release device, facilitating the separation of the cable core.

[0059] When the locking rod and the release elastic body are in the locked state, the end of the locking rod extends into the connecting block and just makes contact with the pin of the locking connecting block and the outer shell. Based on this, the end of the limiting rod can be set as a multi-stage shaft. Through its axial displacement, different rod diameter sections contact the pin, causing the pin to be pushed out and the length of the outer shell to change. By setting a scale on the pin, the axial position of the locking rod can be determined according to the length of the pin pushed out, that is, the state of the release module lock can be determined. It can be divided into locked state, released state, and abnormal position state, which is conducive to intuitive observation and ensures the safety of logging operations.

[0060] Preferably, in this embodiment, the tension bar 43 has the ability to withstand a certain amount of tension. A narrow section is provided in the middle, which is the weak point of tension. When the tension exceeds the tension limit at the weak point, the tension bar 43 will be broken. One end of the tension bar 43 connected to the cable is the tension application end, and the other end is the output end.

[0061] As can be seen from the above structure, the tension bar 43's tension application end is connected to the cable's outer armor via the connecting rod 41, the adapter sleeve 42, and the clamping cone group 7. The tension bar 43's output end is connected to the release elastic body 31 and the outer shell 11 via the connecting block 44. That is, the tension on the cable is transmitted to the release elastic body 31 and the outer shell 11 after passing through the tension bar 43. When the tension exceeds the weak point of the tension bar 43, the cable tends to move away from the outer shell 11 and the release elastic body 31. Therefore, the adapter sleeve 42 and the outer shell 11 tend to slide together. That is, the adapter sleeve 42 enables the tension applied by the cable to be transmitted axially to the connecting rod 41, the tension bar 43, and the release elastic body 31. This allows the desired separation effect to be achieved with less tension, thus protecting the cable.

[0062] Example 6

[0063] Based on Example 5, in this example, the clamping cone group 7, the tension connecting assembly 4, the connecting cylinder 5, and the pin assembly are respectively filled with high-temperature silicone grease between them and the outer shell 11; the outer shell 11 is provided with silicone grease injection holes 12.

[0064] This solution features a simple structure and reasonable design. It utilizes the consistency of high-temperature silicone grease to fix the cable core to a certain extent, while simultaneously forming a flexible buffer zone between the outer shell and internal components. This allows it to adapt to the varying pressure environments of downhole operations. Furthermore, its high-temperature resistance is strong, and its consistency is less affected by temperature changes, enabling it to operate in diverse temperature environments and achieve long-term operation under high temperature and high pressure conditions. In addition, due to its fluidity, it provides good protection, insulation, and sealing when not in use, ensuring reliable connection between the cable and the equipment. When released, it does not obstruct the release action and can protect the exposed cable core during the process.

[0065] Preferably, in this embodiment, a plug is installed at the aforementioned silicone grease injection hole 12.

[0066] Example 7

[0067] Based on any one of Embodiments 5 to 6, in this embodiment, the limiting disk 411, the connecting block 44, and the connecting cylinder 5 are provided with a plurality of wire grooves 8 at uniform intervals in the circumferential direction.

[0068] The scheme has a simple structure and reasonable design. It utilizes multiple pairs of cable grooves 8 to facilitate the internal cable core to pass through each cable groove 8 and connect with the pin assembly 6, thereby achieving the electrical connection required for logging and release operations, thus reducing the impact of tension on the cable core and protecting the cable core.

[0069] The multiple wire guide slots 8 on the limiting plate 411 can be evenly spaced, or they can be symmetrically arranged in pairs corresponding to the two wire guide slots 8 on the rear connecting block 44. The purpose is to organize the multiple core wires inside the cable core according to the wiring sequence, which is beneficial for subsequent wiring and also avoids the mutual tangling between the cable cores, thus protecting the cable core.

[0070] Example 8

[0071] Based on the above embodiments, in this embodiment, the tension bar 43 has a structure that is thin at both ends and thick in the middle, and an annular groove is provided in the middle.

[0072] The structure is designed to be easy to break when the cable is subjected to a certain tensile force, thereby allowing the cable head assembly to separate from the cable head assembly.

[0073] Example 9

[0074] Based on the above embodiments, in this embodiment, the opposite ends of the connecting rod 41 and the connecting block 44 are provided with a fitted square shaft 45, and the opposite ends of the two fitted square shafts 45 are provided with threaded holes; the two ends of the tension rod 43 are respectively threadedly connected to the two threaded holes.

[0075] The scheme has a simple structure and reasonable design, and the tension bar 43 is easy to assemble with other components.

[0076] Preferably, in this embodiment, the housing square shaft 45 is preferably a hexagonal prism structure, which can constrain the relative rotation of the two ends of the tension rod 43, avoid the torque transmitted from the cable from affecting the weak points of the tension rod 43, thereby avoiding abnormal breakage of the tension rod 43 and ensuring the safety and reliability of the connection.

[0077] Example 10

[0078] Based on embodiment 9, in this embodiment, the two sets of square shafts 45 are fitted with connecting sleeves 46. One end of the connecting sleeve 46 is fixedly fitted to the set of square shafts 45 connected to the connecting block 44, and the other end of the connecting sleeve 46 is slidably fitted to the set of square shafts 45 connected to the connecting rod 41. A limiting sleeve 47 is installed between the opposite ends of the two sets of square shafts 45, and the limiting sleeve 47 is fitted over the tension rod 43.

[0079] The square shaft 45 of the sleeve can constrain the relative rotation of the two ends of the tension bar 43, preventing the torque transmitted from the cable from affecting the weak points of the tension bar, thereby preventing abnormal breakage of the tension bar 43 and ensuring the safety and reliability of the connection; in addition, the limiting sleeve 47 can constrain the distance between the connecting rod 41 and the connecting block, so that the square shafts 45 of the two ends of the tension bar can be axially aligned, thereby facilitating the installation of the connecting sleeve 46.

[0080] The assembly process of the releasable connection device provided by the present invention is as follows:

[0081] Pass the cable head through the assembly of the outer shell 11 and the adapter sleeve 42. Leave a certain length of cable at the end of the cable that extends out of the adapter sleeve and mark it. Clamp the cable with a clamp. Pass the matching cone frame through the cable and place it on the cable clamping tool. Wrap it with a rope at the marked point. Then strip the inner and outer steel wires of the cable into a lantern shape and cut it at a certain length away from the binding point. Drive the large cone 72 and the small cone 73 into the corresponding positions and hammer them tightly. Finally, saw off the inner and outer steel wires along the end face of the cone frame 71 and grind them flat. Remove the black protective layer of the armored cable core, remove debris, and clean the cable core.

[0082] The assembled wire clamping cone group 7 is inserted into the adapter sleeve 42, and the two are connected and fixed by the set screw. The cable cores are passed out of the wire passage groove 8 of the limiting plate in sequence, and the limiting plate 411 is locked into the port groove of the adapter sleeve 42 by the locking sleeve 421.

[0083] Then install the tension bar 43. First, put the connecting sleeve 46 on the sleeve square shaft of the connecting rod, thread the tension bar to the end of the connecting rod, put the limiting sleeve on the outside of the tension bar 43, and then thread the tension bar to the connecting block until the connecting block and the connecting rod clamp the limiting sleeve. Push the connecting sleeve 46 to cooperate with the sleeve square shaft on the connecting block. After adjusting it into place, lock the connecting sleeve 46 and the connecting block 44 with the set screw. Pass the cable core through the wire groove 8 on both sides of the connecting sleeve 46 in sequence, and insert it into the corresponding pin on the pin assembly 6 in sequence.

[0084] Align the connecting block 44 with the positioning pin hole on the outer casing 11, and then insert the positioning pin to achieve positioning and installation of the outer casing. Finally, add high-temperature silicone grease through the silicone grease injection hole 12 until it is full, and then install the plug to seal the silicone grease injection hole to complete the installation.

[0085] This invention connects the cable and instrument string via a releasable module, which can actively release the cable in conjunction with cable tension, thereby achieving separation of the cable from the instrument string with less tension and thus better protecting the cable. The cable and releasable module 3 are connected via a tension connection assembly 4. Utilizing the tension weakness of the tension bar 43, if the releasable module 3 fails to release normally, the tension bar 43 can be broken, thus avoiding excessive tension on the cable surface and further protecting the cable.

[0086] The cable head assembly is used to reliably connect to the cable. The tension connection assembly can reliably connect the cable to the release elastomer. The connecting cylinder 5 is used to reliably connect the release device to the instrument string assembly 2. The release elastomer is used to quickly connect to the release device, and the pin assembly 6 is used to quickly connect the cable core to the electrical connector of the instrument string, thereby achieving a reliable and fast connection between the cable and the instrument string.

[0087] This invention provides a releasable connection device for logging cables. It utilizes a heat-fusion self-release module in conjunction with a tension bar weak-point connection to prevent the cable from being broken due to excessive tension during separation. The adapter sleeve and outer casing work together to reduce the required tensile force on the cable. An internal cable core pin assembly is incorporated, and the cable core is protected by high-temperature silicone grease, adapting to the high-temperature, high-pressure, and variable downhole environment. In summary, this effectively protects the cable during both connection and separation, ensuring reliable connection between the cable and the instrument string, as well as rapid and safe separation.

[0088] To overcome the shortcomings of the existing technology, the present invention provides a releasable connection device for logging cables, which satisfies the requirements of reliable connection between the cable and the instrument string and rapid and safe separation; at the same time, the pin assembly of the bridle and the cable core is built into the bridle body, thereby increasing the silicone grease cavity and enhancing the pressure resistance of the bridle.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0090] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A releasable connection device for a logging cable, characterized in that: The device includes a cable head assembly (1), an instrument string assembly (2), a releasable module (3), and a tension connection assembly (4). The cable head assembly (1) includes a wire clamping cone assembly (7) and a housing (11), both ends of which are open. The wire clamping cone assembly (7) is installed inside one end of the housing (11), and the instrument string assembly (2) is installed at the other end of the housing (11). The tension connection assembly (4) includes a connecting rod (41) and a tension bar (43). The connecting rod (41) is installed inside the outer shell (11), and one end of it is connected to the wire clamping cone assembly (7) through an adapter sleeve (42). One end of the tension bar (43) is connected to the other end of the connecting rod (41). The releasable module (3) is installed inside the outer shell (11), and it is connected to the other end of the tension bar (43) through a connecting block (44). The releasable module (3) is connected to the instrument string assembly (2) through a pin assembly (6). The connecting block (44) is fixedly connected to the outer shell (11).

2. The releasable connection device for logging cables according to claim 1, characterized in that: The clamping cone assembly (7) includes a cone frame (71), a large cone (72), and a small cone (73). The cone frame (71), the large cone (72), and the small cone (73) are respectively installed inside the outer shell (11) and are coaxially sleeved from the outside to the inside. The large cone (72) and the small cone (73) are respectively conical in shape, and the small cone (73) has a through-hole for the cable core to pass through. One end of the adapter sleeve (42) is fixedly sleeved outside the cone frame (71).

3. The releasable connection device for logging cables according to claim 2, characterized in that: The outer steel wires of the cable are evenly arranged between the cone frame (71) and the large cone (72), and the inner steel wires of the cable are evenly arranged between the large cone (72) and the small cone (73).

4. The releasable connection device for logging cables according to claim 2, characterized in that: One end of the connecting rod (41) is provided with a limiting plate (411), and the limiting plate (411) is locked into the groove at the other end of the adapter sleeve (42) by a locking sleeve (421).

5. The releasable connection device for logging cables according to claim 4, characterized in that: The releasable module (3) includes a release elastomer (31) and a release mechanism (32) that are interlocked together. The release elastomer (31) is connected to the tension rod (43) through the connecting block (44). The release mechanism (32) is connected to the instrument string assembly (2) through the connecting tube (5), and the connecting tube (5) is sleeved on the outside of the release mechanism (32).

6. The releasable connection device for logging cables according to claim 5, characterized in that: High-temperature silicone grease is filled between the clamping cone assembly (7), the tension connecting assembly (4), the connecting cylinder (5), and the pin assembly (6) and the outer shell (11); the outer shell (11) is provided with silicone grease injection holes (12).

7. The releasable connection device for logging cables according to claim 5, characterized in that: The limiting plate (411), the connecting block (44), and the connecting cylinder (5) are provided with multiple wire grooves (8) evenly spaced in the circumferential direction.

8. The releasable connection device for logging cables according to any one of claims 1-7, characterized in that: The tension bar (43) has a structure that is thin at both ends and thick in the middle, and an annular groove is provided in the middle.

9. The releasable connection device for logging cables according to any one of claims 1-7, characterized in that: The connecting rod (41) and the connecting block (44) are each provided with a fitted square shaft (45) at their opposite ends, and the two fitted square shafts (45) are provided with threaded holes at their opposite ends; the two ends of the tension rod (43) are respectively threaded to the two threaded holes.

10. The releasable connection device for logging cables according to claim 9, characterized in that: The two sets of square shafts (45) are fitted with connecting sleeves (46). One end of the connecting sleeve (46) is fixedly fitted to the set of square shafts (45) connected to the connecting block (44), and the other end of the connecting sleeve (46) is slidably fitted to the set of square shafts (45) connected to the connecting rod (41). A limiting sleeve (47) is installed between the opposite ends of the two sets of square shafts (45), and the limiting sleeve (47) is fitted over the tension bar (43).

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