A multifunctional logging instrument fishing assembly tool

Abstract

The utility model relates to the technical field of falling well instrument string fishing, disclose a multifunctional logging instrument overshot fishing combination tool, through the sequential connection of drill pipe, bent drill pipe and overshot fishing tool, adaptation big belly borehole and the complex fishing working condition of deformation fish head, bent drill pipe design is convenient for accurate search and introduction deformation fish head, effectively solve the fish head positioning problem under special working condition. The built-in fish detection device and overshot device of overshot fishing tool, the fish detection device can confirm the fish head into the barrel state in real time, make up the defect that the prior art lacks the detection of the barrel, the overshot device and overshot head cooperate, realize overshot and fishing integration, improve the operation efficiency. The overall structure design gives consideration to downhole safety and well control safety, adapts to a variety of complex working conditions, significantly improves the success rate of fishing, solves the problems of poor adaptability, insufficient safety guarantee and the like of the existing tool.

Description

Technical Field

[0001] This utility model belongs to the field of well logging instrument string retrieval technology, specifically a multi-functional logging instrument string retrieval combination tool. Background Technology

[0002] In horizontal and complex well logging, the storage logging technique is commonly used. However, this technique is prone to jamming of the logging instrument string during drilling and transportation. Coupled with inadequate on-site handling procedures and improper coordination among relevant parties, logging instrument string breakage accidents are frequent. During the accident handling phase, poor wellbore quality and deformed "fish head" (logging tool head) further increase the difficulty of quickly retrieving the fallen instrument string. Through the summary and analysis of numerous complex storage logging cases and existing retrieval techniques, the milling and retrieval technique has been proven to be the most effective method for handling stuck instrument strings. However, in actual operation, key technical issues such as locating the "fish head," introducing the "fish head," detecting the "fish head" after it enters the casing, the milling and retrieval operation of the stuck instrument string, and ensuring downhole and well control safety all directly affect the overall effectiveness of the milling and retrieval operation. Especially for special retrieval situations where a deformed "fish head" falls into a large-bore well and the instrument string becomes stuck, existing technologies are insufficient to meet the requirements for efficient retrieval.

[0003] To address the aforementioned challenges in fish retrieval, the existing technology discloses a long-tube milling and retrieval integrated combination tool (CN201412101Y). This combination tool consists of a milling head, a milling tube, and a retrieval tool. Its structure is reasonable and compact. In use, the milling tube and retrieval tool are combined and lowered into the well, allowing for the completion of all milling and retrieval operations for the fish in one go. This achieves the completion of both milling and retrieval processes in a single drilling operation, which not only simplifies the construction process and shortens the processing time but also effectively eliminates the risk of the fish sticking again shortly after milling, significantly improving the success rate of stuck drill bit handling. However, this technical solution still has significant shortcomings: it is not designed to adapt to the special working conditions of deformed fish heads and large-bellied wells, making it difficult to accurately locate and reliably introduce deformed fish heads; it lacks an effective detection mechanism after the fish head enters the well casing, making it impossible to confirm the fish head's entry status in a timely manner; its adaptability to complex downhole environments is limited, and the success rate of retrieval in a single attempt is difficult to guarantee when facing complex well conditions such as large-bellied wells; at the same time, it lacks targeted design in terms of downhole safety protection and well control safety assurance for the retrieval tool string, failing to comprehensively solve various key technical hazards in milling and retrieval operations.

[0004] In summary, existing technologies suffer from several drawbacks. Firstly, they present the high risk of instrument string breakage during traditional well logging operations. Secondly, they are difficult to retrieve under complex conditions, and key technical issues in milling and retrieval remain unresolved. Thirdly, existing combined tools suffer from insufficient adaptability to special conditions, lack of fish-head insertion detection functionality, and inadequate safety design. Therefore, developing a versatile, multi-functional logging tool with milling and retrieval capabilities that can handle complex retrieval situations, such as deformed fish-heads landing in large-bore wells and instrument string jamming, simultaneously addressing issues of fish-head locating and introduction, insertion detection, safe retrieval, and downhole and well control safety, while achieving a high success rate in a single retrieval attempt, is a pressing technical challenge in this field. Utility Model Content

[0005] This utility model provides a multifunctional logging tool retrieval combination tool, which solves the complex retrieval problem of deformed fish head falling into a large-bodied well and the instrument string getting stuck.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A multifunctional logging tool retrieval assembly includes a drill pipe, a bent drill pipe, a connector, and a milling and retrieval tool connected in sequence. The milling and retrieval tool includes an upper connector, a cylinder, a retrieval device, a fish entry detection device, and a milling head. The upper end of the upper connector is connected to a safety connector, and the lower end is connected to the cylinder. The cylinder has a hollow structure and houses the fish entry detection device and the retrieval device. The fish entry detection device is connected to the retrieval device and is located near the safety connector. The milling head is connected to the side of the cylinder away from the safety connector.

[0007] Preferably, the safety connector includes a male connector and a female connector, which are connected by a wide-toothed thread. When the rotational torque is greater than 40% of the upper threading torque, the male connector and the female connector are reversed and separated.

[0008] Preferably, the upper connector is provided with a pressure relief device, which includes a pressure relief hole, a countersunk hole, and a rupture disc assembly installed in the countersunk hole. The rupture disc assembly ruptures when the pressure in the well riser reaches a preset value, thereby creating a circulation channel for the drilling fluid.

[0009] Preferably, the pressure relief device has a preset value of 15-25 MPa, and the rupture disc assembly includes a lower clamp, a rupture disc, and an upper clamp installed sequentially from the inside to the outside of the countersunk hole. The fastening screw tightens the lower clamp, the rupture disc, and the upper clamp by threading.

[0010] Preferably, both ends of the cylinder are provided with double-stage buckles, with the upper female buckle connected to the upper connector and the lower male buckle connected to the milling head. The fish detection device and the catching device are installed sequentially along the axial direction of the cylinder.

[0011] Preferably, the fishing device includes a first electrode sliding sleeve, a first bearing seat, a second electrode sliding sleeve and a second bearing seat arranged in sequence. The top of the second electrode sliding sleeve is provided with a countersunk step, and the inner wall of the countersunk hole is provided with a female buckle. It is connected to the corresponding second bearing seat through a connecting sleeve. A one-way thrust bearing is installed between the connecting sleeve and the electrode sliding sleeve.

[0012] Preferably, the first electrode sliding sleeve and the second electrode sliding sleeve are cylindrical, and the side walls of the first electrode sliding sleeve and the second electrode sliding sleeve are provided with windows, and the electrode plates are installed in the windows.

[0013] Preferably, the electrode plate is inserted into the window of the first electrode plate sleeve and the second electrode plate sleeve by a tenon joint and fixed by hexagonal screws, and the upper and lower end faces of the first electrode plate sleeve and the second electrode plate sleeve are chamfered.

[0014] Preferably, the fish entry detection device has a window on its side wall, the fish entry detection device includes a slider, the slider is installed in the window of the device body by a pin, a spring is installed between the slider and the inner wall of the window, the window is covered with a cover plate, the cover plate is fastened to the main body by screws, and a sealing ring is installed on the outer wall of the fish entry detection device.

[0015] Preferably, one end of the milling head is provided with wavy milling teeth, and the other end is provided with a double-stage male thread. Compared with existing technologies, this utility model has the following advantages: This utility model provides a multifunctional logging tool retrieval assembly. Through the sequential connection of drill pipe, curved drill pipe, and milling and retrieval tool, it adapts to complex retrieval conditions such as large-bore wells and deformed fish-head formations. The curved drill pipe design facilitates precise location and introduction of deformed fish-head formations, effectively solving the problem of fish-head positioning under special conditions. The milling and retrieval tool incorporates a fish-entry detection device and a retrieval device. The fish-entry detection device can confirm the fish-head entry status in real time, overcoming the deficiency of entry detection in existing technologies. The retrieval device and the milling head work together to achieve integrated milling and retrieval, improving operational efficiency. The overall structural design considers both downhole safety and well control safety, adapting to various complex conditions, significantly improving the success rate of retrieval in a single attempt, and solving problems such as poor adaptability and insufficient safety assurance of existing tools. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This invention relates to a multifunctional logging tool retrieval assembly. Figure 2 This is a schematic diagram of a milling and fishing tool according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the pressure relief device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the fishing device according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the fish detection device according to an embodiment of the present invention; In the diagram, 1-drill rod, 2-bent drill rod, 3-safety joint, 4-milling and fishing tool, 5-deformed fish head, 4-1-upper joint, 4-2-cylinder body, 4-3-fishing device, 4-4-fish entry detection device, 4-5-milling head, 4-1-1-upper clamp, 4-1-2-fastening screw, 4-1-3-rupture disc, 4-1-4-lower clamp, 4-3-1-first electrode plate sleeve, 4-3-2-first bearing seat, 4-3-3-second electrode plate sleeve, 4-3-4-one-way thrust bearing, 4-3-5-connecting sleeve, 4-3-6-second bearing seat, 4-4-1-cover plate, 4-4-2-slider, 4-4-3-pin, 4-4-4-spring, 4-4-5-sealing ring. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" 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 communication between two components.

[0022] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0023] like Figure 1 As shown in the figure, this utility model embodiment provides a multifunctional logging tool retrieval assembly, including a drill pipe 1, a bent drill pipe 2, a connector 3, and a milling and retrieval tool 4 connected in sequence. The milling and retrieval tool 4 includes an upper connector 4-1, a cylinder 4-2, a retrieval device 4-3, a fish entry detection device 4-4, and a milling head 4-5. The upper end of the upper connector 4-1 is connected to the safety connector 3, and the lower end is connected to the cylinder 4-2. The cylinder 4-2 has a hollow structure and houses the fish entry detection device 4-4 and the retrieval device 4-3. The fish entry detection device 4-4 is connected to the retrieval device 4-3 and is located on the side of the cylinder 4-2 away from the safety connector 3. The milling head 4-5 is connected to the side of the cylinder 4-2 away from the safety connector 3.

[0024] The sequential connection of drill pipe 1, curved drill pipe 2, and milling and fishing tool 4 adapts to complex fishing conditions such as large-bore wells and deformed fish heads 5. The curved drill pipe 2 is designed to facilitate precise location and introduction of the deformed fish head 5, effectively solving the problem of fish head positioning under special conditions. The milling and fishing tool 4 incorporates a fish entry detection device 4-4 and a fishing device 4-3. The fish entry detection device 4-4 can confirm the fish head's entry status in real time, compensating for the lack of entry detection in existing technologies. The fishing device 4-3 and the milling head 4-5 work together to achieve integrated milling and fishing, improving operational efficiency. The overall structural design takes into account both downhole safety and well control safety, adapts to various complex conditions, significantly improves the success rate of one-time fishing, and solves the problems of poor adaptability and insufficient safety assurance of existing tools.

[0025] The detailed device is as follows: The overall structure of this utility model is as follows: Figure 1 As shown, it is specifically composed of drill rod 1, bent drill rod 2, safety joint 3, milling and retrieval cylinder 4, and deformed fish head 5.

[0026] Drill pipe 1 connects individual pipes, each approximately 10m in length, together via threaded connectors. This extends the drill string, transmits drilling pressure and rotational torque, and transports the fishing tool string.

[0027] The bent drill pipe 2 serves the same purpose as the bent connector. Depending on the well conditions, bent drill pipes with different angles are processed on-site to increase the scanning range of the fishing tool string, thereby achieving the fish-finding effect and guiding the fish head that has fallen into the wellbore into the fishing tube.

[0028] Safety joint 3: When the milling and fishing tool gets stuck, the rotational torque will cause the safety joint to open from between the male and female joints connected by the wide sawtooth thread, leaving the male joint and the lower milling and fishing tool in the well, thereby releasing the fishing tool string.

[0029] Logging tool milling and fishing tool 4, structure as follows Figure 2 As shown.

[0030] The upper connector 4-1 has a 410 drill bit thread output at the upper end, which connects to a 5" drill bit or safety connector; the lower end has a double-stage thread, which connects to the cylinder 4-2. The pressure relief holes designed on the upper connector consist of four through holes evenly distributed on the pipe wall. Countersunk holes are drilled from the outside in through these through holes, and internal threads are machined into the countersunk holes. The countersunk holes are used to house a pressure relief device consisting of a lower clamp 4-1-4, a rupture disc 4-1-3, and an upper clamp 4-1-1. The pressure relief device is as follows... Figure 3 As shown, the device consists of a hexagonal threaded ring, a sealing ring, and a hollow screw, fastened to the pressure relief hole by a 4-1-2 fastening screw. The pressure relief device is typically made of 304 stainless steel, and the rupture disc is designed with a burst pressure of 15-25 MPa in various models. In the event of a well control emergency during retrieval, if the standpipe pressure exceeds the design pressure of the upper connector pressure relief device, the rupture disc leaks, and drilling fluid flows from the upper connector pressure relief hole into the annulus, thus re-establishing the circulation channel.

[0031] The cylinder 4-2 is a hollow tubular shell, the length of which can be selected according to the technical parameters of the object being dropped. Both ends of the connection are double-stage buckles; the end connecting to the upper connector is a female buckle, and the end connecting to the milling head is a male buckle. The cylinder contains a fish entry detection device, electrode plate sleeves, bearing seats, connecting sleeves, and one-way thrust bearings. The installation sequence is: fish entry detection device 4-4, first electrode plate sleeve 4-3-1, first bearing seat 4-3-2, second electrode plate sleeve 4-3-3, second bearing seat 4-3-6.

[0032] The retrieval device 4-3 consists of two bearing seats and two electrode sliding sleeves, as shown below. Figure 4 As shown. The first electrode sleeve 4-3-1 and the second bearing housing 4-3-2 are independent. The second electrode sleeve 4-3-3 and the second bearing housing 4-3-6 are connected together by a connecting sleeve 4-3-5 and a thrust bearing 4-3-4. In the design, the second electrode sleeve 4-3-3 is based on the first electrode sleeve 4-3-1. A countersunk step is machined downward on the top surface of the second electrode sleeve 4-3-3, and a female thread is machined on the inner wall of the countersunk hole. The step is used to install the one-way thrust ball bearing 4-3-4. The female thread of the second electrode sleeve 4-3-3 is connected to the second bearing housing 4-3-6 through the connecting sleeve, so that the electrode sleeve only bears the downward drilling pressure during the retrieval operation, and does not bear the rotational torque during milling, and will not rotate with the rotation of the retrieval cylinder or the bearing housing.

[0033] The design of the first bearing seat 4-3-2 and the second bearing seat 4-3-6 inside the cylinder ensures that the electrode sleeve remains in a grabbing state when the retrieval cylinder is in the milling state, preventing damage to the electrode plate under rotational torque. The first bearing seat 4-3-1 has an axially mounted rolling bearing with an outer diameter 4mm smaller than the inner diameter of the cylinder wall. The second bearing seat 4-3-6 has an axially mounted rolling bearing and an axial groove machined around its lower part for mounting the connecting sleeve. A thrust bearing is installed at the connection between the connecting sleeve and the electrode sleeve. The axial rolling bearing and the one-way thrust bearing on the bearing seats release the torque on the electrode sleeve during the milling operation, thus smoothly achieving the milling and unloading operation.

[0034] The first and second pole plate sleeves 4-3-1 and 4-3-3 inside the cylinder are the main components of the object-catching body. They are cylindrical in shape, with 1-2 bearings at each end, embedded in the sidewall circumference of the sleeve body. Typically, six pole plates are installed within the window of the sleeve body. Each pole plate is tenon-and-mortise inserted into the sidewall and secured with hexagonal screws. During retrieval, the outward expansion force of the pole plates and the tensile force borne by the retrieval tool string are evenly distributed across the sleeve body, thus providing good protection for each pole plate. Both the upper and lower ends of the pole plate sleeves are chamfered to further improve fish entry and retrieval efficiency. The designed pole plate sleeves can retrieve objects within a range of 54-80mm; the breaking tensile force of the pole plates is >120KN. When the tensile load on the retrieval tool string exceeds the breaking tensile force of the pole plates, the retrieval tool string can be safely withdrawn.

[0035] Fish entry detection device 4-4, this device has a slider structure design, such as... Figure 5As shown, the device consists of several parts, including a cover plate 4-4-1, a slider 4-4-2, a pin 4-4-3, a spring 4-4-4, and a sealing ring 4-4-5. Two sealing rings designed on the outer wall of the fish entry detection device prevent mud cake and other impurities from entering the space between the retrieval device 4-3 and the cylinder wall from the end of the milling head during drilling, thus hindering the vertical movement of the electrode sleeve within the cylinder. During assembly, different models of sliders are selected according to the size of the object dropped downhole. The sliders are first installed sequentially inside the main body window of the device, and the slider stroke is fixed with screws. After installing the spring, cover plate, and sealing rings, the assembled fish entry detection device 4-4 is inserted into the lower step of the cylinder through the female buckle end. During retrieval, the deformed fish head compresses the slider inside the device, causing it to contract inwards. The expansion and contraction space after the slider compresses the spring ensures the smooth passage of the deformed fish head. Under drilling pressure, the undeformed instrument body passes through the detection device and enters the electrode sleeve. At this time, the change in pump pressure can determine whether the fish has entered the retrieval cylinder, thus achieving the effect of fish entry detection.

[0036] The milling head 4-5 has a wave-shaped design on one end and a milling tooth structure with 6 wave shapes. Its main function is to find and move the fish head or downhole sand and guide the fish head into the retrieval tube. The other end is designed with a double-stage male thread for connection with the retrieval body. The milling head can withstand a large torque during milling operations.

[0037] Deformed fish head 5 refers to a fishing head whose tip has deformed or bent. When the logging instrument string gets stuck, it breaks off and falls into the well under tensile and compressive loads. The deformed fish head becomes a major factor affecting the entry of the fallen instrument string into the retrieval tool.

[0038] This invention can effectively solve the problem of retrieving deformed fish heads stuck in logging instrument strings under complex working conditions, achieving the purpose of rapid processing, and is conducive to the further implementation of drilling, transportation and storage logging technology.

[0039] During milling and fishing operations, the fishing tool string is first lowered to the top of the fish head. The pump is then turned on to circulate and flush the top of the fish, using circulating drilling fluid to bring sediment and other foreign objects from the well to the surface, preparing for introducing the fish head into the fishing tool assembly 4. After flushing the top of the fish, the pump continues to lower the drill string, and the rotary table is started to rotate the fishing tool string. The rotating milling head 4-5 introduces the deformed fish head 5 into the fishing tube. When the fish head enters the tube, it squeezes any contact slider of the fish entry detection device 4-4. During the spring compression process, the inner diameter of the detection device gradually increases until the deformed fish head 5 passes through smoothly. After the deformed fish head passes through the fish entry detection device 4-4, the slider returns to its original position under the action of elastic force. Under the action of drilling pressure, the fish head is further introduced into the pole plate sleeve of the fishing device 4-3. At this time, the gap between the outer diameter of the instrument string body and the inner diameter of the slider is 5-10mm. During fishing, the pump pressure change before and after the object passes through the fish entry detection device can be used to determine whether the instrument string has entered the fishing tube.

[0040] After confirming the fish head has entered the barrel, continue lowering the drill string. The fish head will push open the retrieval electrode plate installed inside the sliding sleeve and continue moving upwards, passing through each component of the retrieval device in sequence until the bearing seat 4-3-6 contacts the lower end face of the upper connector 4-1, at which point the electrode plate sliding sleeve stops moving upwards. If the instrument string is unstuck, lift the retrieval tool string. The electrode plate sliding sleeve will move downwards, and the electrode plate, under the action of elastic force, will completely lock at the smallest diameter point of the instrument string. Then lift the retrieval tool string to complete the retrieval operation.

[0041] If the retrieval tool string encounters resistance at the depth of the fish head and there is no change in pump pressure, it indicates that the resistance is due to wellbore quality or after passing the fish head. First, treat it as a buried fish head; if this is ineffective, proceed with the retrieval of a hidden fish head. When retrieving a hidden fish head, rotate the retrieval tool string and increase its scanning range by bending the drill pipe 2. Use auxiliary tools such as a milling head to hook out the fish head 5 hidden in the large wellbore and guide it into the retrieval tool string. Only after a significant change in pump pressure can it be confirmed that the fish head has entered the wellbore.

[0042] If the fish head enters the milling sleeve and the retrieval tool string is lifted, the load increases. Attempt to release the stuck tool string within the safe pulling force range. If the release fails, switch to milling operation. Under the action of drilling pressure and torque, loosen and break the loose block, or peel the stuck tool string off the well wall so that it no longer affects the retrieval of the tool string, until the tool string can be released under the action of lifting load.

[0043] If the tool string cannot be released after retrieval, the sliding sleeve plate can be broken under the lifting load to remove its clamping force, allowing the retrieval tool string to be retrieved. During the entire retrieval and release process, if the retrieval tool string gets stuck at the large diameter, rotate the retrieval tool string. When the torque is greater than 40% of the upper closing torque, reverse the connection thread of safety connector 3 to release safety connector 3 and retrieve the upper tool string. If well control risks arise due to suction during the tripping process after retrieval, the drilling fluid can be circulated by starting the pump. When the pressure in the well standpipe is higher than the bursting pressure of the rupture disc, the rupture disc opens, and the drilling fluid returns from the pressure relief device, establishing a new circulation channel. After the well control hazard is handled, the retrieval tool string can be slowly retrieved.

[0044] In summary, when the head of a stuck logging instrument string deforms after falling into the well, improper tool selection during retrieval may not only prevent the head from being inserted into the retrieval tube, but may also fail to unstick the logging instrument string after retrieval. Conventional milling and retrieval techniques are not only time-consuming but may also create well control hazards and new engineering complexities, adding new risks to the retrieval process. This invention addresses the rapid retrieval of instruments that have fallen into the well due to improper handling after becoming stuck during storage logging operations. The developed retrieval tool, powered by the drilling pressure and rotational torque provided by the drill pipe, can retrieve objects that have fallen from the logging instrument string when the fish head is deformed. It can also locate and guide the fish head when it becomes trapped in the logging instrument string by adjusting the scanning range of the bent drill pipe and the milling head. Once the deformed fish head is detected as being inside the casing by the fish detection device, the retrieval tool string is rotated. Under the action of rotational torque, the stuck instrument string is dislodged, and under the action of drilling pressure, the electrode sliding sleeve completes the retrieval operation. If a well control emergency occurs after retrieval, or if the milling and retrieval casing becomes stuck due to sand accumulation, the pump can be activated to release the pressure and open the rupture disc of the pressure relief device, establishing a new circulation channel. Alternatively, the retrieval tool string can be opened by reversing the connection thread at the safety joint, and the drill pipe above the male joint can be pulled out to release the retrieval tool.

[0045] This invention optimizes the retrieval process for a stuck logging instrument string with a deformed fish head that has broken off and fallen into an open hole well. It achieves the goals of finding the fish, detecting the fish, and retrieving the logging instrument string in a single well run. In the event of a well control emergency, it can re-establish a circulation channel and rotate to release the milling and retrieval cylinder. Its application prospects are broad, and there is a strong demand for its use in the field.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0047] 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 be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications made to the technical solutions based on the technical concept proposed by this utility model shall fall within the scope of protection of the claims of this utility model.

Claims

1. A multifunctional logging tool and retrieval combination tool, characterized in that, The device includes a drill rod (1), a bent drill rod (2), a connector (3), and a milling and fishing tool (4) connected in sequence. The milling and fishing tool (4) includes an upper connector (4-1), a cylinder (4-2), a fishing device (4-3), a fish entry detection device (4-4), and a milling head (4-5). The upper end of the upper connector (4-1) is connected to the safety connector (3), and the lower end is connected to the cylinder (4-2). The cylinder (4-2) is a hollow structure. The fish entry detection device (4-4) and the fishing device (4-3) are built into the cylinder (4-2). The fish entry detection device (4-4) is connected to the fishing device (4-3). The fish entry detection device (4-4) is located on the side closer to the safety connector (3). The milling head (4-5) is connected to the side of the cylinder (4-2) away from the safety connector (3).

2. The multifunctional logging tool and retrieval combination tool according to claim 1, characterized in that, The safety connector (3) includes a male connector and a female connector, which are connected by a wide sawtooth thread. When the rotational torque is greater than 40% of the upper torque, the male connector and the female connector are reversed and separated.

3. The multifunctional logging tool and retrieval combination tool according to claim 1, characterized in that, The upper connector (4-1) is equipped with a pressure relief device, which includes a pressure relief hole, a countersunk hole, and a rupture disc assembly installed in the countersunk hole. The rupture disc assembly ruptures when the pressure in the well riser reaches a preset value, so that the drilling fluid forms a circulation channel.

4. A multifunctional logging tool and retrieval combination tool according to claim 3, characterized in that, The pressure relief device has a preset value of 15-25MPa. The rupture disc assembly includes a lower clamp (4-1-4), a rupture disc (4-1-3), and an upper clamp (4-1-1) installed sequentially from the inside to the outside of the countersunk hole. The lower clamp (4-1-4), the rupture disc (4-1-3), and the upper clamp (4-1-1) are tightened by the threaded engagement of the fastening screw (4-1-2).

5. A multifunctional logging tool and retrieval combination tool according to claim 1, characterized in that, Both ends of the cylinder (4-2) are provided with double-stage buckles. The upper female buckle is connected to the upper connector (4-1), and the lower male buckle is connected to the milling head (4-5). The fish detection device (4-4) and the catching device (4-3) are installed sequentially along the axial direction of the cylinder (4-2).

6. A multifunctional logging tool and retrieval combination tool according to claim 1, characterized in that, The fishing device (4-3) includes a first electrode sliding sleeve (4-3-1), a first bearing seat (4-3-2), a second electrode sliding sleeve (4-3-3), and a second bearing seat (4-3-6) arranged in sequence. The top of the second electrode sliding sleeve (4-3-3) is provided with a countersunk step, and the inner wall of the countersunk hole is provided with a female buckle. It is connected to the corresponding second bearing seat (4-3-6) through a connecting sleeve (4-3-5). A one-way thrust bearing (4-3-4) is installed between the connecting sleeve (4-3-5) and the electrode sliding sleeve (4-3-3).

7. A multifunctional logging tool and retrieval combination tool according to claim 6, characterized in that, The first electrode sliding sleeve (4-3-1) and the second electrode sliding sleeve (4-3-3) are cylindrical. The side walls of the first electrode sliding sleeve (4-3-1) and the second electrode sliding sleeve (4-3-3) are provided with windows, and electrode plates are installed in the windows.

8. A multifunctional logging tool and retrieval combination tool according to claim 7, characterized in that, The electrode plate is inserted into the window of the first electrode plate sleeve (4-3-1) and the second electrode plate sleeve (4-3-3) by tenon and mortise and tenon and fixed by hexagonal screws. The upper and lower end faces of the first electrode plate sleeve (4-3-1) and the second electrode plate sleeve (4-3-3) are chamfered.

9. A multifunctional logging tool and retrieval combination tool according to claim 1, characterized in that, The fish entry detection device (4-4) has a window on its side wall. The fish entry detection device (4-4) includes a slider (4-4-2). The slider (4-4-2) is installed in the window of the main body of the device by means of a pin (4-4-3). A spring (4-4-4) is installed between the slider (4-4-2) and the inner wall of the window. The window is covered with a cover plate (4-4-1), which is fastened to the main body by screws. A sealing ring (4-4-5) is installed on the outer wall of the fish entry detection device (4-4).

10. A multifunctional logging tool and retrieval combination tool according to claim 1, characterized in that, The milling head (4-5) has wavy milling teeth at one end and double-stage male threads at the other end.

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