A fishing and launching device and MWD while drilling measuring instrument

Abstract

The application discloses a fishing and releasing device and a MWD (Measurement While Drilling) instrument, and relates to the technical field of downhole fishing devices. The fishing and releasing device comprises a fisherman, wherein the fisherman comprises a base, two fishing hooks and an elastic connecting piece. The fisherman in the fishing and releasing device provided by the application is towed by a steel wire rope, and the fisherman is driven to move downwards by mud pressure. The setting mode of the fishing hooks in the fisherman can capture the spear head without rotating the fisherman. When it is necessary to lower an inner drilling tool, the inner drilling tool is lowered to a position by the fisherman, a releasing device is lowered, and the mud pressure is utilized to release the inner drilling tool by the fishing hooks, so that the inner drilling tool is lowered. The application further provides a MWD instrument used in cooperation with the fishing and releasing device. The scheme provided by the application can realize fishing and releasing, and is convenient and easy to operate.

Description

Technical Field

[0001] This invention relates to the field of downhole fishing equipment technology, and in particular to a fishing and deployment device and a MWD (Measuring While Drilling) instrument. Background Technology

[0002] With the continuous development of the oil and gas field and geological drilling industry, directional drilling technology, as one of the most advanced drilling technologies in the world's oil exploration and development field, has increasingly higher requirements for construction technology and precision. Adopting directional drilling technology allows for the economical and effective development of oil and gas resources limited by surface and underground conditions, significantly increasing oil and gas production and reducing drilling costs, while also protecting the natural environment, resulting in significant economic and social benefits. In directional drilling, the MWD (Measuring While Drilling) instrument is a core component with high value. It acts as the eyes of the drilling personnel, allowing them to understand the drilling trajectory in real time. However, when the MWD instrument malfunctions downhole, its battery is low, or in horizontal drilling, the external drill string becomes stuck or other drilling accidents occur, making it impossible to retrieve the external drill string, current solutions mainly involve lifting the drill string for inspection or blasting to loosen the threads, or abandoning the drill string, resulting in significant economic losses and a waste of considerable construction time.

[0003] Current MWD (Measuring While Drilling) instruments are mainly used for retrieval, such as the MWD retrieval tool for horizontal open wells described in CN114482899A. It mainly consists of four parts: a converter head, a retrieval tube, a clamp, and a spring. Retrieval is achieved by spring compression. This retrieval tool is lowered through the drill pipe, which takes a long time and can only retrieve instruments.

[0004] CN209603915U describes a retrieval device for retrieving wireless drilling instruments. This device can deploy and retrieve MWD instruments by lowering a rotating retrieval hook into the wellhead. During deployment, it can be rotated to release the stuck object. However, the structure of this device is too complicated and the construction is difficult, especially since it requires the use of steel wire ropes in the horizontal section to achieve rotational retrieval and release. Summary of the Invention

[0005] The purpose of this invention is to provide a retrieval and deployment device and a MWD (Measuring While Drilling) instrument to solve the problems existing in the prior art, enabling retrieval and deployment with convenient and easy construction.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a salvage and deployment device, comprising: a salvage device, the salvage device including a base, two salvage hooks and an elastic connector; the base is used to connect with a steel wire rope, the two salvage hooks are arranged opposite each other and are hinged to the base by the same pin, the first end of the two salvage hooks is provided with a hook, and the second end is connected by the elastic connector. The two hooks are opposite each other, and under normal conditions, under the elastic force of the elastic connector, the gap between the two salvage hooks is less than the maximum cross-sectional size of the salvage spearhead. The salvage device moves toward the salvage spearhead under the pressure of mud, and the salvage hooks open under the reaction force of the salvage spearhead, allowing the salvage spearhead to enter the inside of the hooks so that the hooks hook the salvage spearhead.

[0008] Preferably, it also includes a release device, which includes a release sleeve for connecting to the wire rope. The release sleeve moves toward the fishing hook under mud pressure until the second end of the fishing hook enters the release sleeve. The inner wall of the release sleeve compresses the second end of the fishing hook, causing the two hooks to move away from each other.

[0009] Preferably, both the base and the unblocking sleeve are provided with a straightening ring, and the straightening ring is provided with a flow hole.

[0010] Preferably, a limiting pin is provided between the hinged part of the two fishing hooks and the hook, the two ends of the limiting pin are connected to the base, and the limiting pin is located between the two fishing hooks.

[0011] Preferably, the base is provided with an installation cavity that extends from one end of the base to the other end. Two retrieval hooks are disposed in the installation cavity. The second end of each retrieval hook extends from the side wall of the installation cavity. The second end of each retrieval hook is provided with an inclined first guide surface. The distance between the two first guide surfaces gradually increases from the second end toward the first end.

[0012] The present invention also provides a measurement while drilling (MWD) instrument, including an inner drill string and an outer drill string, wherein the outer drill string is used to connect to the drill pipe, the inner drill string is seated inside the outer drill string, and the top structure of the inner drill string is a retrieval spearhead.

[0013] Preferably, the internal drilling tool further includes a retrieval pipe, a fixed seat, a fixed post, and two opposing spring clips. One end of the retrieval pipe is connected to the retrieval spearhead. The fixed seat is fixedly connected to one end of the fixed post. The fixed seat sits directly or indirectly on the stepped surface inside the external drilling tool. The other end of the fixed post is inserted into the other end of the retrieval pipe and can move axially within the retrieval pipe. The fixed post has an axially extending mounting hole that penetrates the fixed post radially. The two spring clips are located in the mounting hole and connected to the fixed post by elastic pins. The retrieval pipe has an elongated hole corresponding to the mounting hole. One end of the spring clip extends from the elongated hole. A limiting hole is provided on the recovery pipe. Both ends of the elastic pin extend into the limiting hole. The diameter of the limiting hole is larger than the diameter of the elastic pin. The retrieval spearhead moving towards the wellhead can drive the recovery pipe to move. A spring clip groove is provided inside the outer drilling tool. Under normal conditions, the fixed seat sits directly or indirectly on the stepped surface inside the outer drilling tool, and the spring clip is located in the spring clip groove. When the retrieval spearhead moves towards the wellhead, it drives the recovery pipe to move. The spring clip retracts under the pressure of the recovery pipe and moves out of the spring clip groove. The recovery pipe drives the elastic pin, the fixed column, and the fixed seat to move towards the wellhead.

[0014] Preferably, the end of the fixing base away from the retrieval spearhead is provided with a pulse generator section, a battery section, a directional instrument section, and a guide shoe assembly in sequence, and the fixing base, the pulse generator section, the battery section, the directional instrument section, and the guide shoe assembly are fixedly connected in sequence.

[0015] Preferably, the guide shoe assembly is provided with four limiting grooves, which are evenly arranged around the circumference of the guide shoe assembly. The limiting grooves extend from the bottom to the top of the guide shoe assembly. The side wall of the limiting groove is provided with an installation groove. An elastic shear pin is provided in the installation groove. The elastic shear pin extends out of the installation groove. The bottom of the extended part is provided with a second guide surface. The second guide surface gradually extends downward from one end of the elastic shear pin to the other end. An directional key is provided on the inner wall of the outer drill bit. The directional key enters the limiting groove from the bottom opening of the limiting groove and presses the second guide surface, causing the elastic shear pin to extend and retract inward so that the directional key enters the bottom of the limiting groove.

[0016] Preferably, the MWD (Measuring While Drilling) instrument is provided with a centralizing ring, and the centralizing ring is provided with a flow hole.

[0017] The present invention achieves the following technical effects compared to the prior art:

[0018] First, the retrieval device in the retrieval and deployment equipment provided by the present invention uses a steel wire rope for traction and retrieval, and uses mud pressure to drive the retrieval device to move downward. Moreover, the retrieval hook in the retrieval device is set in a way that can capture the spearhead without rotating the retrieval device.

[0019] Secondly, when it is necessary to lower the inner drilling tool, after the inner drilling tool is lowered into place using the retrieval device, the retrieval hook is released by lowering the release device and using mud pressure, thereby achieving the purpose of lowering the inner drilling tool. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the retrieval device provided in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the card unlocker provided in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the internal drilling tool provided in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the external drilling tool provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of the internal drilling tool, external drilling tool, fishing tool, and unsticking tool working together.

[0026] Figure 6 The MWD (Measuring While Drilling) instrument provided in this embodiment of the invention;

[0027] Figure 7 This is a schematic diagram of the boot assembly.

[0028] Figure 8 for Figure 7 The front view;

[0029] Figure 9 for Figure 7 A sectional view;

[0030] In the diagram: 1-retrieval device; 2-unstick device; 3-inner drill string; 4-outer drill string; 10-centering ring;

[0031] 11-Retrieval hook; 12-Base; 13-Elastic connector; 14-Limit pin; 15-Pin; 16-Mounting cavity;

[0032] 21-Unlocking sleeve;

[0033] 31-Retrieval spearhead; 32-Recovery tube; 33-Ejector clip; 34-Fixing base; 35-Pulse generator sub-section; 36-Battery sub-section; 37-Orientation instrument sub-section; 38-Guide shoe assembly; 39-Ejector clip holder;

[0034] 381-Limiting groove; 382-Elastic shear pin;

[0035] 311 - Second elastic pin; 312 - Spear holder; 314 - First elastic pin;

[0036] 41-Salvage external connector; 42-Spring clip external connector; 43-Non-magnetic drill collar; 44-Directional connector; 45-Directional key; 46-Spring clip slot. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Example 1

[0040] This embodiment provides a retrieval and deployment device, such as... Figure 1 As shown, it includes: a retrieval device 1, which includes a base 12, two retrieval hooks 11, and an elastic connector 13; the base 12 is used to connect with a wire rope, the two retrieval hooks 11 are arranged opposite each other and are hinged to the base 12 by the same pin 15, the first end of the two retrieval hooks 11 is provided with a hook, and the second end is connected by the elastic connector 13. The two hooks are opposite each other. Under normal conditions, under the elastic force of the elastic connector 13, the gap between the two retrieval hooks 11 is less than the maximum cross-sectional size of the retrieval spearhead 31. The retrieval device 1 moves toward the retrieval spearhead 31 under the pressure of mud. The retrieval hooks 11 open under the reaction force of the retrieval spearhead 31 and allow the retrieval spearhead 31 to enter the inside of the hook so that the hook hooks catch the retrieval spearhead 31.

[0041] The salvage and deployment equipment provided by this invention is suitable for MWD (Measuring While Drilling) instruments equipped with salvage spearheads 31.

[0042] When in use, the retrieval device 1 is dropped into the well. When the retrieval device 1 is obstructed from descending, the pump is turned on to drive the retrieval device 1 to continue descending through mud pressure until the retrieval device 1 can no longer descend. The descent depth is calculated and the retrieval spearhead 31 on the MWD (Measuring While Drilling) instrument is reached. The pump is turned on again to allow the retrieval device 1 to capture the retrieval spearhead 31, that is, the two hooks open and hook the retrieval spearhead 31. The wire rope is then pulled up and the internal drill string 3 in the MWD instrument is taken out for maintenance.

[0043] The retrieval device 1 in this invention is pulled and retrieved by a steel wire rope. The retrieval device 1 is driven to move downward by the pressure of the mud. The retrieval hook 11 in the retrieval device 1 is set in a way that can capture the spearhead 31 without rotating the retrieval device 1.

[0044] In some embodiments, the above embodiments only function as retrieval instruments, while for deployment, such as Figure 2 As shown, the salvage and deployment device provided in this embodiment of the invention also includes a release device 2. The release device 2 includes a release sleeve 21, which is used to connect with the wire rope. Under the pressure of the mud, the release sleeve 21 moves toward the salvage hook 11 until the second end of the salvage hook 11 enters the release sleeve 21. The inner wall of the release sleeve 21 compresses the second end of the salvage hook 11, causing the two hooks to move away from each other.

[0045] In use, first use the retrieval tool 1 to lower the inner drill string 3 into position. Then, the unsticking device 2 needs to be lowered to pull the retrieval tool 1 out of the well. One end of the unsticking device 2 is connected to a steel wire rope. The unsticking device 2 falls freely first. When it can no longer descend, turn on the small pump to push the unsticking device 2 with the mud pressure. After the lower end of the unsticking device 2 contacts the retrieval tool 1, under the action of the pump pressure, the unsticking device 2 is pressed into the retrieval hook 11, causing the retrieval hook 11 to disengage. At this time, it can be seen that the unsticking device 2 can no longer descend. Combined with the length of the drill string, it can be determined whether the unsticking device 2 has completed the unsticking. At this time, stop the pump and pull up the unsticking device 2 and the retrieval tool 1, thus completing the deployment of the inner drill string 3.

[0046] In some embodiments, the unblocking sleeve 21 has a spiral notch. When the unblocking device 2 is lowered, it can be directly put onto the wire rope of the retrieval device 1 through the notch. The spiral notch increases the difficulty of the unblocking sleeve 21 detaching from the wire rope. After successful unblocking, lifting the retrieval device 1 can drive the unblocking device 2 to be lifted synchronously.

[0047] In some embodiments, both the base 12 and the unstick 2 are provided with a centralizing ring 10, which has a flow passage. The flow passage is mainly used when the fishing device 1 or the unstick 2 cannot move forward after being lowered into the inclined or horizontal section of the well. It is necessary to pressurize and push the fishing device 1 and the unstick 2 until the corresponding work is completed. The flow passage area outside the unstick 2 is smaller than the flow passage area outside the base 12. This ensures that the pressure at the top of the unstick 2 is greater than the pressure at the bottom, and that the unstick 2 can continue to descend.

[0048] In some embodiments, a limiting pin 14 is provided between the hinged portion of the two retrieval hooks 11 and the hook itself. The two ends of the limiting pin 14 are connected to the base 12, and the limiting pin 14 is located between the two retrieval hooks 11. The limiting pin 14 is used to limit the retrieval hooks 11, preventing the retrieval hooks 11 from closing too tightly, which would prevent the retrieval spearhead 31 from entering between the two retrieval hooks 11 during retrieval.

[0049] In some embodiments, a mounting cavity 16 is provided in the base 12, the mounting cavity 16 extends from one end of the base 12 to the other end, two fishing hooks 11 are provided in the mounting cavity 16, the second end of the fishing hook 11 extends out from the side wall of the mounting cavity 16, the second end of the fishing hook 11 is provided with an inclined first guide surface, and the distance between the two first guide surfaces gradually increases from the second end toward the first end.

[0050] Example 2

[0051] This embodiment provides a MWD (Measuring While Drilling) instrument, such as... Figures 3-9 As shown, it includes an inner drill bit 3 and an outer drill bit 4. The outer drill bit 4 is used to connect to the drill rod, and the inner drill bit 3 sits inside the outer drill bit 4. The top structure of the inner drill bit 3 is a retrieval spearhead 31.

[0052] The MWD measurement-while-drilling instrument provided in this embodiment is used in conjunction with the salvage and deployment equipment described in Embodiment 1.

[0053] The outer drill bit 4 is connected to the bottom of the drill pipe, and the inner drill bit 3 includes measuring instruments, such as pulse generator sub 35, battery sub 36, and directional instrument sub 37.

[0054] The inner drill bit 3 needs to be positioned inside the outer drill bit 4. Therefore, in some embodiments, the inner drill bit 3 also includes a retrieval pipe 32, a fixed seat 34, a fixed post, and two opposing spring clips 33. One end of the retrieval pipe 32 is connected to the retrieval spearhead 31. The fixed seat 34 is fixedly connected to one end of the fixed post. The fixed seat 34 sits directly or indirectly on the stepped surface inside the outer drill bit 4. The other end of the fixed post is inserted from the other end of the retrieval pipe 32 and can move axially in the retrieval pipe 32. The fixed post is provided with an axially extending mounting hole that penetrates the fixed post radially. The two spring clips 33 are located in the mounting hole and connected to the fixed post by elastic pins. The retrieval pipe 32 has corresponding mounting holes. The outer drilling tool 4 has an elongated hole, with one end of the spring clip 33 extending out of the elongated hole. The recovery pipe 32 has a limiting hole, and both ends of the elastic pin extend into the limiting hole. The diameter of the limiting hole is larger than the diameter of the elastic pin. When the retrieval spearhead 31 moves toward the wellhead, it can drive the recovery pipe 32 to move. The outer drilling tool 4 has a spring clip groove 46. Under normal conditions, the fixed seat 34 sits directly or indirectly on the stepped surface inside the outer drilling tool 4, and the spring clip 33 is located in the spring clip groove 46. When the retrieval spearhead 31 moves toward the wellhead, it drives the recovery pipe 32 to move. Under the pressure of the recovery pipe 32, the spring clip 33 retracts and moves out of the spring clip groove 46. The recovery pipe 32 drives the elastic pin, the fixed column, and the fixed seat 34 to move toward the wellhead.

[0055] During normal use, the fixed seat 34 sits directly or indirectly on the stepped surface inside the outer drill string 4, the recovery pipe 32 sits on the fixed seat 34, and the spring clip 33 is located in the spring clip groove 46. When subjected to bottom hole pressure, because the top of the spring clip 33 is a flat structure, the spring clip 33 will not come out of the spring clip groove 46 when subjected to vertical upward pressure, thus enabling the inner drill string 3 to be positioned in the outer drill string 4.

[0056] When the MWD (Measuring While Drilling) instrument needs to be removed from the well for maintenance, the fishing spearhead 31 is first captured by the fishing tool 1, and the fishing tool 1 is pulled upward → the fishing spearhead 31 moves upward → the recovery pipe 32 moves upward → the spring clip 33 retracts → the elastic pin abuts against the bottom of the limiting hole → driving the fixed column, fixed seat 34 and the structure below the fixed seat 34 to move upward → completing the fishing.

[0057] In some embodiments, the end of the mounting base 34 away from the retrieval spearhead 31 is provided with a pulse generator section 35, a battery section 36, a directional instrument section 37, and a guide shoe assembly 38 in sequence, and the mounting base 34, the pulse generator section 35, the battery section 36, the directional instrument section 37, and the guide shoe assembly 38 are fixedly connected in sequence.

[0058] Specifically, the guide shoe assembly 38 is provided with four limiting grooves 381. The four limiting grooves 381 are evenly arranged around the circumference of the guide shoe assembly 38. The limiting grooves 381 extend from the bottom to the top of the guide shoe assembly 38. The side wall of the limiting groove 381 is provided with an installation groove. An elastic shear pin 382 is provided in the installation groove. The elastic shear pin 382 extends out of the installation groove. The bottom of the extended part is provided with a second guide surface. The second guide surface extends gradually downward from the end of the elastic shear pin 382 to the other end. The inner wall of the outer drill bit 4 is provided with a directional key 45. The directional key 45 enters the limiting groove 381 from the bottom opening of the limiting groove 381 and squeezes the second guide surface, causing the elastic shear pin 382 to extend and retract inward so that the directional key 45 enters the bottom of the limiting groove 381.

[0059] The guide shoe assembly 38 is used to position the inner drill string 3 in a specific orientation within the outer drill string 4, which is for circumferential positioning of the inner drill string 3.

[0060] When the inner drill string 3 is raised, the elastic shear pin 382 shears off, thus achieving the upward movement. When the inner drill string 3 is lowered after maintenance, a new elastic shear pin 382 needs to be replaced.

[0061] Specifically, the elastic shear pin 382 consists of a pin and a spring.

[0062] In some embodiments, a centralizing ring 10 is provided outside the MWD (Measuring While Drilling) instrument, and the centralizing ring 10 is provided with a flow hole.

[0063] In some embodiments, one end of the recovery tube 32 and the retrieval spearhead 31 can be fixedly connected in a conventional manner, or they can be connected by a retrieval spearhead seat 312, a first elastic pin 314, and a second elastic pin 311. Specifically, both ends of the retrieval spearhead seat 312 extend into the recovery tube 32 and the retrieval spearhead 31, respectively, and are connected to the recovery tube 32 by the first elastic pin 314 and to the retrieval spearhead 31 by the second elastic pin 311.

[0064] The specific usage process is as follows:

[0065] 1. Before construction, assemble the internal drill bit 3 on the ground, check that all threads are tightened, and connect the ground machine to test the instruments to ensure they are working properly.

[0066] 2. After the outer drilling tool 4 is connected on the drilling rig, the inner drilling tool 3 is lifted by the retrieval device 1 and put into the outer drilling tool 4;

[0067] 3. Use the unjamming device 2 to unjamm the retrieval device 1, remove the retrieval device 1, complete the assembly of the inner and outer drilling tools 4, connect the drilling tools, start the pump to test the instrument signals and the orientation tool face;

[0068] 4. Connect the drill pipe and lower it into the well for drilling operations. When the MWD (Measuring While Drilling) instrument has no signal or the battery is dead, unscrew the drill pipe and connect it to the retrieval device 1 via the winch wire rope. Lower the retrieval device 1 to retrieve the inner drill string 3. When the retrieval device 1 cannot descend further, the pump can be turned on at a small displacement to allow the retrieval device 1 to continue descending until the retrieval device 1 can no longer descend. Calculate the descent depth and reach the upper end of the retrieval spearhead 31. Continue to turn on the pump to allow the retrieval device 1 to capture the retrieval spearhead 31.

[0069] 5. Raise the retrieval device 1 with the wire rope, break the elastic shear pin 382 used for positioning the guide shoe, and continue to raise it until the internal drill string 3 is retrieved. Replace or repair the battery of the MWD instrument on the ground. After completion, reconnect the ground machine to test whether the instrument is working properly.

[0070] 6. After replacing the elastic shear pin 382 for the guide shoe, use the wire rope with the retrieval tool 1 to re-deploy the MWD instrument. After encountering resistance during descent, start the pump at a small displacement to push it down. Calculate the descent depth and stop the pump when it is the same as the retrieval depth, indicating that the descent has reached the target depth. At this time, continue to start the pump and check whether the difference between the tool face and the tool face before the last retrieval is 0°, 90°, 180° or 270°. If the difference between the tool face and the tool face is these values, it means that the orientation key 45 is in place.

[0071] 7. Thread the release device 2 onto the wire rope and deploy it. Then turn on the pump to push it downwards, so that the lower end of the release device 2 squeezes the retrieval hook 11 to release the retrieval spearhead 31. Then slowly lift the wire rope and check the suspended weight. If the suspended weight is light, it means that the release was successful. Then lift the retrieval device 1.

[0072] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A measurement-while-drilling (MWD) instrument, characterized in that: It includes an inner drill string and an outer drill string. The outer drill string is used to connect to the drill pipe. The inner drill string is located inside the outer drill string. The top structure of the inner drill string is a retrieval spearhead, which is used in conjunction with a retrieval and deployment device. The salvage and deployment equipment includes a salvage device, which comprises a base, two salvage hooks, and an elastic connector. The base is used to connect with a steel wire rope. The two salvage hooks are arranged opposite each other and are hinged to the base via the same pin. The first end of each salvage hook is provided with a hook, and the second end is connected via the elastic connector. The two hooks are opposite each other. Under normal conditions, under the elastic force of the elastic connector, the gap between the two salvage hooks is less than the maximum cross-sectional size of the salvage spearhead. The salvage device moves toward the salvage spearhead under the pressure of the mud. The salvage hooks open under the reaction force of the salvage spearhead, allowing the salvage spearhead to enter the inside of the hooks and thus hook the salvage spearhead. The salvage and deployment equipment also includes a release device, which includes a release sleeve for connecting to a wire rope. Under mud pressure, the release sleeve moves toward the salvage hook until the second end of the salvage hook enters the release sleeve. The inner wall of the release sleeve compresses the second end of the salvage hook, causing the two hooks to move away from each other. Both the base and the release sleeve are provided with a straightening ring, and the straightening ring has a flow hole. The flow area outside the release device is smaller than the flow area outside the base. The internal drilling tool also includes a recovery pipe, a fixed base, a fixed column, and two opposing spring clips. One end of the recovery pipe is connected to the retrieval spearhead. The fixed base is fixedly connected to one end of the fixed column. The other end of the fixed column is inserted into the other end of the recovery pipe and can move axially within the recovery pipe. The fixed column has an axially extending mounting hole that penetrates the fixed column radially. The two spring clips are located in the mounting hole and connected to the fixed column by elastic pins. The recovery pipe has elongated holes corresponding to the mounting holes. One end of the spring extends from the elongated hole. A limiting hole is provided on the recovery pipe. Both ends of the elastic pin extend into the limiting hole. The diameter of the limiting hole is larger than the diameter of the elastic pin. A spring chuck groove is provided inside the outer drill bit. Under normal conditions, the fixed seat sits directly or indirectly on the stepped surface inside the outer drill bit, and the spring chuck is located in the spring chuck groove. When the retrieval spearhead moves toward the wellhead, it drives the recovery pipe to move. The spring chuck retracts under the pressure of the recovery pipe and moves out of the spring chuck groove. The recovery pipe drives the elastic pin, the fixed column, and the fixed seat to move toward the wellhead.

2. The MWD (Measuring While Drilling) instrument according to claim 1, characterized in that: A limiting pin is provided between the hinged part of the two fishing hooks and the hook, and the two ends of the limiting pin are connected to the base. The limiting pin is located between the two fishing hooks.

3. The MWD (Measuring While Drilling) instrument according to claim 1, characterized in that: The base has an installation cavity that extends from one end of the base to the other. Two retrieval hooks are disposed in the installation cavity. The second end of each retrieval hook extends from the side wall of the installation cavity. The second end of each retrieval hook has an inclined first guide surface. The distance between the two first guide surfaces gradually increases from the second end toward the first end.

4. The MWD (Measuring While Drilling) instrument according to claim 1, characterized in that: The fixed base, at the end away from the retrieval spearhead, is sequentially provided with a pulse generator section, a battery section, a directional instrument section, and a guide shoe assembly. The fixed base, the pulse generator section, the battery section, the directional instrument section, and the guide shoe assembly are sequentially and fixedly connected.

5. The MWD (Measuring While Drilling) instrument according to claim 4, characterized in that: The guide shoe assembly has four limiting grooves on its exterior, which are evenly arranged around the circumference of the guide shoe assembly. The limiting grooves extend from the bottom to the top of the guide shoe assembly. The side wall of the limiting groove has an installation groove, and an elastic shear pin is provided in the installation groove. The elastic shear pin extends out of the installation groove, and the bottom of the extended part has a second guide surface. The second guide surface gradually extends downward from one end of the elastic shear pin to the other end. The inner wall of the outer drill bit has a directional key. The directional key enters the limiting groove through the bottom opening of the limiting groove and presses against the second guide surface, causing the elastic shear pin to extend and retract inward so that the directional key enters the bottom of the limiting groove.

6. The MWD (Measuring While Drilling) instrument according to claim 1, characterized in that: The MWD (Measuring While Drilling) instrument is equipped with a centralizing ring, and the centralizing ring has overflow holes.

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