Downhole Instrument Anti-Fall Tools and Methods

Abstract

This invention relates to the field of drilling tooling technology, and more particularly to a downhole instrument anti-fall tool and method, aiming to solve the technical problem of simultaneously preserving downhole instruments and preventing further damage during a blowout hazard. The downhole instrument anti-fall tool includes a fastener, an outer sleeve, and a support ring. The fastener is used to thread a steel wire cable and is locked in place with the cable. The outer sleeve is tubular with a boss on its inner wall and is used to connect the blowout preventer valve to the stuck drill string. The support ring is used to thread the steel wire cable and is configured to fall into the outer sleeve along with the fastener during a fall, abutting against the fastener and the boss. Using this downhole instrument anti-fall tool can reduce the unnecessary workload caused by the complication of an accident and may even save a well.

Description

Technical Field

[0001] This invention relates to the field of drilling tooling technology, and in particular to a downhole instrument anti-falling tool and method thereof. Background Technology

[0002] When drilling deep or ultra-deep wells, if a stuck drill occurs after the oil and gas layer has been exposed, and wireline work is carried out, oil and gas intrusion and overflow hazards frequently occur. Currently, there are two main approaches to dealing with overflow hazards:

[0003] The first approach is to activate the wireline cable reel to pull the downhole instruments to the wellhead as much as possible, and then reconnect the blowout preventer (BOP) at the wellhead. The second approach, if necessary, is to cut the wireline cable to lower the downhole instruments back into the well, and then quickly reconnect the BOP at the wellhead. For overflow wells, the former approach, with its rapid retrieval of downhole instruments, can easily create suction pressure, accelerating the overflow and leading to a worse situation; the latter approach can cause the downhole instruments to fall directly to the bottom of the well or into the drill string's waterhole, creating difficulties for subsequent retrieval operations or even resulting in the loss of the downhole instruments. Summary of the Invention

[0004] The purpose of this invention is to provide a downhole instrument anti-fall tool and method to solve the technical problem of being unable to simultaneously preserve downhole instruments and prevent worse situations when facing a spill hazard.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] In a first aspect, the present invention provides a downhole instrument anti-fall tool, comprising: a fastener, an outer sleeve, and a support ring;

[0007] The fastener is used to thread the steel wire cable and to lock it in place with the steel wire cable.

[0008] The outer sleeve is tubular, and its inner wall is provided with a boss. The outer sleeve is used to connect the blowout preventer and the stuck drill bit.

[0009] The support ring is used to thread the steel wire cable and is configured to fall into the outer sleeve along with the fastener during the falling process, and abut against the fastener and the boss.

[0010] Furthermore, the fastener includes a pressure plate, which has a plurality of threaded holes, and a limiting groove is provided on the surface of the pressure plate from one end to the other.

[0011] The pressure plate consists of two symmetrically distributed plates, which are connected by bolts passing through the threaded holes, so that the two limiting grooves enclose each other to form a wire passage hole.

[0012] Furthermore, from one end of the outer sleeve to the other end, the channel of the outer sleeve is sequentially divided into a conical hole, a first straight hole, and a second straight hole;

[0013] The small end of the conical hole is connected to the first straight hole, and the diameter of the first straight hole is greater than the diameter of the second straight hole and equal to the diameter of the small end of the conical hole.

[0014] Furthermore, the end of the outer sleeve with the tapered hole is provided with an internal thread for threaded connection with the blowout preventer plug;

[0015] The end of the outer sleeve with the second straight hole is provided with an external thread for threaded connection with the stuck drill bit.

[0016] Furthermore, the supporting ring includes a threading platform and a supporting claw;

[0017] The threading station is provided with a first U-shaped groove extending along its own axis.

[0018] Around the axis of the threading table, a plurality of support claws are spaced apart on the side of the threading table and are fixedly connected to the threading table.

[0019] Furthermore, the downhole instrument anti-fall tool also includes an inner sleeve;

[0020] The inner sleeve is tubular, with a second threaded hole on its side wall, and an opening on its side wall from one end to the other.

[0021] The two ends of the inner sleeve are used to abut against the fastener and the support ring, respectively.

[0022] Furthermore, the downhole instrument anti-fall tool also includes an auxiliary platform, which is used to support the support ring and is provided with a clearance hole for threading a steel wire cable.

[0023] Furthermore, the auxiliary platform includes a support platform, an open ring, and a support rod;

[0024] The support platform is provided with a second U-shaped groove;

[0025] The openings of the open ring and the second U-shaped groove face the same direction;

[0026] Multiple support rods are spaced apart around the axis of the open ring, with one end of each support rod fixedly connected to the open ring and the other end fixedly connected to the support platform.

[0027] Secondly, the present invention also provides a method for preventing downhole instruments from falling, comprising the following steps:

[0028] S100: Connect the outer sleeve to the stuck drill bit via threads before drilling;

[0029] S200: Connect the two pressure plates with bolts to tighten the steel wire cable;

[0030] S300: The support ring is fitted onto the steel wire cable and placed inside the outer sleeve of the boss;

[0031] S400: Cut the steel wire cable and then put the cut end of the steel wire cable into the outer sleeve;

[0032] S500: Connect the outer sleeve to the blowout preventer via a threaded connection.

[0033] Furthermore, in step S200, in the event of an emergency, the two pressure plates are connected on the auxiliary platform to lock the steel wire cable.

[0034] In summary, the technical effects achieved by the downhole instrument anti-fall tool provided by this invention are as follows:

[0035] The downhole instrument anti-fall tool provided by the present invention includes a fastener, an outer sleeve, and a support ring; the fastener is used to thread a steel wire cable and locks with the steel wire cable; the outer sleeve is tubular with a boss on its inner wall and is used to connect between the blowout preventer and the stuck drill bit; the support ring is used to thread a steel wire cable and is configured to fall into the outer sleeve along with the fastener during the falling condition, and abut against the fastener and the boss.

[0036] In this downhole instrument anti-fall tool, when the fastener and support ring enter the outer sleeve, the support ring will sit on the boss and simultaneously support the fastener. In application, the outer sleeve is connected to the stuck drill string at the wellhead beforehand. In case of an emergency, the support ring is inserted into the outer sleeve, the fastener and wire cable are locked together, and then the wire cable is cut. The fastener and the cut end of the wire cable are then placed into the outer sleeve. After completion, the other end of the outer sleeve is connected to the blowout preventer. This secures the outer sleeve, which in turn prevents the fastener and support ring from falling, thus preventing the downhole instrument connected to the wire cable from falling into the well.

[0037] It can be seen that, compared with existing technologies, this downhole instrument anti-fall tool can prevent downhole instruments from falling into the well and eliminate the problem of worsening dangers caused by pulling up downhole instruments. Using this downhole instrument anti-fall tool can reduce the amount of unnecessary work caused by the complication of accidents and may even save a well. Attached Figure Description

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is an assembly diagram of the downhole instrument anti-fall tool connected to the steel wire cable according to an embodiment of the present invention;

[0040] Figure 2 This is an assembly diagram of the downhole instrument anti-fall tool provided in an embodiment of the present invention.

[0041] Icons: 100 - Fastener; 110 - Pressure plate;

[0042] 200 - Outer sleeve; 210 - Boss;

[0043] 300 - Support ring; 310 - Threading platform; 320 - Support claw;

[0044] 400-Inner sleeve;

[0045] 500 - Auxiliary platform; 510 - Support platform; 520 - Open ring; 530 - Support rod. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the 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 invention without inventive effort are within the scope of protection of the invention.

[0048] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0049] Currently, there are two approaches to dealing with a blowout: one is to activate the wireline drum to pull the downhole instruments to the wellhead as much as possible, and then connect the blowout preventer (BOP) at the wellhead; the other is to cut the wireline if necessary, allowing the downhole instruments to fall back into the well, and then quickly connect the BOP at the wellhead. For a blowout well, the former approach, with its rapid retrieval of downhole instruments, can easily create suction pressure, accelerating the blowout and leading to a worse situation; the latter approach can cause the downhole instruments to fall directly to the bottom of the well or into the drill string's waterhole, creating difficulties for subsequent retrieval or even resulting in the loss of the downhole instruments.

[0050] In view of this, the present invention provides a downhole instrument anti-fall tool, including a fastener 100, an outer sleeve 200, and a support ring 300; the fastener 100 is used to thread a steel wire cable and is locked in place with the steel wire cable; the outer sleeve 200 is tubular, and its inner wall is provided with a boss 210, and the outer sleeve 200 is used to connect between the blowout preventer and the stuck drill bit; the support ring 300 is used to thread a steel wire cable and is configured to fall into the outer sleeve 200 along with the fastener 100 during the falling condition, and abut against the fastener 100 and the boss 210.

[0051] In this downhole instrument anti-fall tool, when the fastener 100 and the support ring 300 enter the outer sleeve 200, the support ring 300 will sit on the boss 210 and simultaneously support the fastener 100. In application, the outer sleeve 200 is connected to the stuck drill string at the wellhead beforehand. In case of an emergency, the support ring 300 is inserted into the outer sleeve 200, the fastener 100 is locked to the wire cable, the wire cable is then cut, and the fastener 100 and the cut end of the wire cable are placed into the outer sleeve 200. After completion, the other end of the outer sleeve 200 is connected to the blowout preventer. This secures the outer sleeve 200, which in turn prevents the fastener 100 and the support ring 300 from falling, thus preventing the downhole instrument connected to the wire cable from falling into the well.

[0052] It can be seen that, compared with existing technologies, this downhole instrument anti-fall tool can prevent downhole instruments from falling into the well and eliminate the problem of worsening dangers caused by pulling up downhole instruments. Using this downhole instrument anti-fall tool can reduce the amount of unnecessary work caused by the complication of accidents and may even save a well.

[0053] The following combination Figure 1 and Figure 2 The structure and shape of the downhole instrument anti-fall tool provided in this embodiment are described in detail:

[0054] Further reference Figure 1The fastener 100 includes a pressure plate 110, which has multiple threaded holes. From one end of the pressure plate 110 to the other end, the surface of the pressure plate 110 has a limiting groove. There are two pressure plates 110, which are symmetrically distributed and connected by bolts passing through the threaded holes, so that the two limiting grooves enclose to form a wire passage hole.

[0055] Specifically, the steel wire cable is brought into contact with the groove surface of the limiting groove. The distance between the two pressure plates 110 can be adjusted using bolts. Utilizing the compressibility of the steel wire cable, the two pressure plates 110 and the steel wire cable will be interference-fitted to lock the steel wire cable. With this design, the fastener 100 and the steel wire cable are simple to lock, easy to operate, and can save time.

[0056] Further reference Figure 1 and Figure 2 The support ring 300 includes a threading platform 310 and support claws 320; the threading platform 310 is provided with a first U-shaped groove extending along its own axis; around the axis of the threading platform 310, a plurality of support claws 320 are spaced apart on the side of the threading platform 310 and are fixedly connected to the threading platform 310.

[0057] by Figure 2 For example, the cable threading platform 310 can be quickly fitted onto the cable through the first U-shaped groove, and the support ring 300 can be placed on the boss 210 through the support claw 320, preventing it from falling. In addition, the adjacent support claws 320 are spaced apart to provide a channel for normal circulating drilling fluid, ensuring that there is no pressure buildup during well control, and in the event of an overflow, the support ring 300 can be placed easily and quickly.

[0058] refer to Figure 2 The downhole instrument anti-fall tool also includes an inner sleeve 400; the inner sleeve 400 is tubular, with a second threaded hole on its side wall, and an opening on its side wall from one end to the other; the two ends of the inner sleeve 400 are used to abut against the fastener 100 and the support ring 300 respectively.

[0059] Specifically, through the opening, the inner sleeve 400 can be quickly fitted onto the wire cable. Its second threaded hole engages with the set screw to further secure the wire cable and prevent it from falling with the downhole instruments. It should also be noted that when the inner sleeve 400 and fastener 100 are inside the outer sleeve 200, an annular space is formed between both and the inner wall of the outer sleeve 200, ensuring normal flow of drilling fluid.

[0060] Further reference Figure 1 The downhole instrument anti-fall tool also includes an auxiliary platform 500, which is used to support the support ring 300 and is provided with a clearance hole for threading steel wire cables.

[0061] Continue to refer to Figure 1The auxiliary platform 500 includes a support platform 510, an open ring 520, and support rods 530. The support platform 510 is provided with a second U-shaped groove, and the openings of the open ring 520 and the second U-shaped groove face the same direction. Here, the break of the open ring 520 and the second U-shaped groove are clearance holes, through which steel wire cables can be directly passed through the auxiliary platform 500. Multiple support rods 530 are distributed at intervals around the axis of the open ring 520, and one end of the support rod 530 is fixedly connected to the open ring 520, and the other end is fixedly connected to the support platform 510.

[0062] With the above design, in the event of an emergency, the two pressure plates 110 can lock the steel wire cable on the support platform 510, which plays an auxiliary role. The structure of the auxiliary platform 500 ensures that overflow and backflow of slurry do not cause pressure buildup in the event of an emergency, making operation safe and reliable. After the two pressure plates 110 have completed the locking operation on the auxiliary platform 500, the auxiliary platform 500 is removed, and the steel wire cable is tested to determine whether it is locked. After confirming that it is locked, the steel wire cable is cut and the broken ends are tidied up. Then, the outer sleeve 200 is inserted, and the outer sleeve 200 is connected to the connector of the blowout preventer. This completes the on-site operation.

[0063] Further reference Figure 2 The outer sleeve 200 has an internal thread at the end with the tapered hole for threaded connection with the blowout preventer plug; the outer sleeve 200 has an external thread at the end with the second straight hole for threaded connection with the stuck drill bit. From one end of the outer sleeve 200 to the other, the channels of the outer sleeve 200 are sequentially divided into a tapered hole, a first straight hole, and a second straight hole; the small end of the tapered hole is connected to the first straight hole, and the diameter of the first straight hole is larger than the diameter of the second straight hole and equal to the diameter of the small end of the tapered hole.

[0064] Continue to refer to Figure 2 The design of the two ends of the outer sleeve 200 allows it to be quickly connected to the drill bit and blowout preventer. The tapered hole design creates a chamfer at the upper end of the outer sleeve 200, which facilitates the insertion of the support ring 300. The connection between the first straight hole and the second straight hole forms a boss 210, which is close to the lower end of the outer sleeve 200. This provides sufficient space for the outer sleeve 200 to hold the broken end of the steel wire cable when it is cut, thus facilitating better connection of its upper end to the blowout preventer.

[0065] The present invention also provides a method for preventing downhole instrument fall-off tools, which includes the following steps:

[0066] S100: Before drilling, thread the outer sleeve 200 to the stuck drill bit; S200: Connect the two pressure plates 110 with bolts to tighten the wire cable; S300: Sleeve the support ring 300 onto the wire cable and place it inside the boss 210 of the outer sleeve 200; S400: Cut the wire cable and then insert the cut end into the outer sleeve 200; S500: Thread the outer sleeve 200 to the blowout preventer plug. In step S200, in case of an emergency, the two pressure plates 110 are connected on the auxiliary platform 500 to lock the wire cable.

[0067] This anti-fall-off method, through this tool, avoids well failure due to stuck drill bit accidents or further complication of the accident, prevents sudden overflow events, and prevents downhole instruments from falling into the well.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tool for preventing downhole instruments from falling, characterized in that, include: Fastener (100), outer sleeve (200), and support ring (300); The fastener (100) is used to thread the steel wire cable and lock it in place with the steel wire cable; The outer sleeve (200) is tubular, and its inner wall is provided with a boss (210). The outer sleeve (200) is used to connect the blowout preventer and the stuck drill bit. The support ring (300) is used to thread the steel wire cable and is configured to fall into the outer sleeve (200) along with the fastener (100) during the falling condition, and abut against the fastener (100) and the boss (210). The fastener (100) includes a pressure plate (110), which has a plurality of first threaded holes, and a limiting groove is provided on the surface of the pressure plate (110) from one end to the other. The pressure plate (110) is provided in two pieces, the two pressure plates (110) are symmetrically distributed, and are connected by bolts passing through the first threaded hole, so that the two limiting grooves are enclosed to form a wire passage hole; The downhole instrument anti-fall tool also includes an auxiliary platform (500), which is used to support the support ring (300) and is provided with a clearance hole for threading steel wire cable; The auxiliary platform (500) includes a support platform (510), an open ring (520), and a support rod (530); The support platform (510) is provided with a second U-shaped groove; The openings of the open ring (520) and the second U-shaped groove face the same direction; Multiple support rods (530) are spaced apart around the axis of the open ring (520), and one end of each support rod (530) is fixedly connected to the open ring (520), and the other end is fixedly connected to the support platform (510). In case of an emergency, the two pressure plates (110) are connected on the auxiliary platform (500) to lock the steel wire cable.

2. The downhole instrument anti-fall tool according to claim 1, characterized in that, From one end of the outer sleeve (200) to the other end, the channels of the outer sleeve (200) are sequentially divided into a conical hole, a first straight hole, and a second straight hole; The small end of the conical hole is connected to the first straight hole, and the diameter of the first straight hole is greater than the diameter of the second straight hole and equal to the diameter of the small end of the conical hole.

3. The downhole instrument anti-fall tool according to claim 2, characterized in that, The end of the outer sleeve (200) with the tapered hole is provided with an internal thread for threaded connection with the anti-blowout plug; The outer sleeve (200) has an external thread at the end with the second straight hole for threaded connection with the stuck drill bit.

4. The downhole instrument anti-fall tool according to claim 1, characterized in that, The support ring (300) includes a threading platform (310) and a support claw (320); The threading station (310) is provided with a first U-shaped groove extending along its own axis; Around the axis of the threading table (310), a plurality of support claws (320) are spaced apart on the side of the threading table (310) and are fixedly connected to the threading table (310).

5. The downhole instrument anti-fall tool according to claim 1, characterized in that, The downhole instrument anti-fall tool also includes an inner sleeve (400); The inner sleeve (400) is tubular, with a second threaded hole on its side wall, and an opening is provided on its side wall from one end to the other. The two ends of the inner sleeve (400) are used to abut against the fastener (100) and the support ring (300), respectively.

6. A method for preventing downhole instruments from falling, characterized in that, Based on the downhole instrument anti-fall tool as described in any one of claims 1 to 5, the following steps are included: S100: Connect the outer sleeve (200) to the stuck drill bit before drilling; S200: Connect the two pressure plates (110) with bolts to tighten the steel wire cable; S300: The support ring (300) is fitted onto the steel wire cable and placed inside the boss (210) of the outer sleeve (200); S400: Cut the wire cable and then put the cut end of the wire cable into the outer sleeve (200); S500: Connect the outer sleeve (200) to the blowout preventer via a threaded connection.

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