Downhole instrument anti-falling tool and anti-falling method thereof

Abstract

The invention relates to the technical field of well drilling tools, in particular to a downhole instrument anti-falling tool and an anti-falling method thereof, and aims to solve the technical problem that in the case of an overflow dangerous case, storage of a downhole instrument and avoiding of a more dangerous case cannot be taken into account at the same time. The downhole instrument anti-falling tool comprises a fastener, an outer sleeve and a bearing ring. The fastener is used for penetrating through the steel wire cable and is locked and matched with the steel wire cable; the outer sleeve is tubular, a boss is arranged on the inner wall of the outer sleeve, and the outer sleeve is used for being connected between the blowout prevention cock and a clamped drilling tool. The bearing ring is used for a steel wire cable to penetrate through and is configured to fall into the outer sleeve together with the fastener under the falling working condition and abut against the position between the fastener and the boss. By adopting the anti-falling tool for the underground instrument, the subsequent redundant workload caused by the complication of accidents can be reduced, and even one well can be saved.

Description

Technical Field

[0001] The invention relates to the technical field of drilling tooling, and in particular to a downhole instrument anti-falling tool and an anti-falling method thereof. Background Art

[0002] When drilling deep or ultra-deep wells, after uncovering the oil and gas layer, the drilling well is often stuck and the wireline operation is carried out. Oil and gas invasion often occurs, resulting in overflow danger. At present, there are two ways to deal with overflow danger:

[0003] The first is to start the steel cable drum, lift the downhole instrument out of the wellhead as much as possible, and then connect the wellhead anti-blowout cock; the second is to cut the steel cable when necessary, so that the downhole instrument falls into the well, and then quickly connect the wellhead anti-blowout cock. For overflow wells, these two methods are prone to suction pressure when the downhole instrument is quickly lifted, thereby accelerating the overflow and causing worse danger; the latter will cause the downhole instrument to fall directly into the bottom of the well or the water hole of the drilling tool, which will cause difficulties in the next step of salvage or loss of the downhole instrument. Summary of the invention

[0004] The purpose of the present invention is to provide a downhole instrument anti-fall tool and an anti-fall method thereof, so as to solve the technical problem that it is impossible to take both the preservation of downhole instruments and the avoidance of worse dangers into consideration when facing an overflow danger.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[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 pass the steel wire cable and is locked with the steel wire cable;

[0008] The outer sleeve is tubular, and a boss is provided on its inner wall. The outer sleeve is used to connect between the blowout prevention cock and the stuck drill bit;

[0009] The supporting ring is used for passing the steel cable, and is configured to fall into the outer sleeve together with the fastener under a falling condition, and abut between the fastener and the boss.

[0010] Furthermore, the fastener comprises a pressing plate, a plurality of threaded holes are provided on the pressing plate, and a limiting groove is provided on the surface of the pressing plate from one end to the other end;

[0011] The pressing plates are provided with two pieces, which are symmetrically distributed and connected by bolts passing through the threaded holes, so that the two limiting grooves are enclosed to form a wire passing hole.

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

[0013] The small end of the tapered 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 tapered hole.

[0014] Furthermore, the end of the outer sleeve having the tapered hole is provided with an internal thread for threaded connection with the anti-blowout cock;

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

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

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

[0018] Around the axis of the threading platform, a plurality of support claws are distributed at intervals on the side of the threading platform and are fixedly connected to the threading platform.

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

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

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

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

[0023] Further, 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 opening directions of the open ring and the second U-shaped groove are consistent;

[0026] A plurality of support rods are distributed at intervals around the axis of the open ring, and one end of the support rod is fixedly connected to the open ring, and the other end is fixedly connected to the support platform.

[0027] In a second aspect, the present invention further provides a method for preventing a downhole instrument from falling, comprising the following steps:

[0028] S100: Before drilling, the outer sleeve is threadedly connected to the stuck drill bit;

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

[0030] S300: Sleeve the support ring on the steel cable and place it on the boss inside the outer sleeve;

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

[0032] S500: Connect the outer sleeve to the anti-blowout cock thread.

[0033] Furthermore, in step S200, when a dangerous situation occurs, two pressure plates are connected on the auxiliary platform to complete the locking of the steel wire cable.

[0034] In summary, the technical effects that can be achieved by the downhole instrument anti-fall tool provided by the present invention are:

[0035] The downhole instrument anti-fall tool provided by the present invention comprises a fastener, an outer sleeve and a supporting ring; the fastener is used for threading a steel wire cable and is locked with the steel wire cable; the outer sleeve is tubular, and a boss is provided on its inner wall, and the outer sleeve is used to connect between the anti-blowout cock and the stuck drill bit; the supporting ring is used for threading a steel wire cable, and is configured to fall into the outer sleeve together with the fastener under a falling condition, and abut between the fastener and the boss.

[0036] In the downhole instrument anti-fall tool, when the fastener and the support ring enter the outer sleeve, the support ring will sit on the boss and support the fastener at the same time. When in use, the outer sleeve is connected to the stuck drill bit at the wellhead in advance. When a dangerous situation occurs, the support ring is put into the outer sleeve, the fastener is locked with the steel cable, and then the steel cable is cut, and the fastener and the broken end of the steel cable are put into the outer sleeve. After completion, the other end of the outer sleeve is connected to the anti-blowout cock, so that the outer sleeve is fixed, and the outer sleeve prevents the fastener and the support ring from falling, thereby preventing the downhole instrument connected to the steel cable from falling into the well.

[0037] It can be seen that compared with the existing technology, the downhole instrument anti-fall tool can prevent the downhole instrument from falling into the well, and at the same time can eliminate the problem of worse danger caused by lifting the downhole instrument; the use of the downhole instrument anti-fall tool can improve the subsequent redundant workload caused by the complication of the accident, and even save a well. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 An assembly diagram of a downhole instrument anti-fall tool provided in an embodiment of the present invention when connected to a steel wire cable;

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

[0041] Icon: 100-fastener; 110-pressure plate;

[0042] 200-outer sleeve; 210-boss;

[0043] 300-supporting 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 DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0047] 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 invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0049] At present, there are two ways to deal with overflow danger: one is to start the steel cable drum, lift the downhole instrument out of the wellhead as much as possible, and then connect the wellhead anti-blowout cock; the other is to cut the steel cable when necessary, so that the downhole instrument falls into the well, and then quickly connect the wellhead anti-blowout cock. For overflow wells, these two methods are prone to suction pressure when the downhole instrument is quickly lifted, thereby accelerating the overflow and causing worse dangers; the latter will cause the downhole instrument to fall directly into the bottom of the well or the water hole of the drilling tool, which will cause difficulties in the next step of salvage or loss of the downhole instrument.

[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 supporting ring 300; the fastener 100 is used to pass the steel wire cable and is locked 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 anti-blowout plug and the stuck drill bit; the supporting ring 300 is used to pass the steel wire cable, and is configured to fall into the outer sleeve 200 together with the fastener 100 under a falling condition, and abut between the fastener 100 and the boss 210.

[0051] In the downhole instrument anti-falling tool, when the fastener 100 and the support ring 300 enter the outer sleeve 200, the support ring 300 will be seated on the boss 210 and support the fastener 100 at the same time. When in use, the outer sleeve 200 is connected to the stuck drill tool in advance at the wellhead. When a dangerous situation occurs, the support ring 300 is put into the outer sleeve 200, the fastener 100 is locked with the steel cable, and then the steel cable is cut, and the fastener 100 and the broken end of the steel cable are put into the outer sleeve 200. After completion, the other end of the outer sleeve 200 is connected to the anti-blowout cock, so that the outer sleeve 200 is fixed, and the outer sleeve 200 prevents the fastener 100 and the support ring 300 from falling, thereby preventing the downhole instrument connected to the steel cable from falling into the well.

[0052] It can be seen that compared with the existing technology, the downhole instrument anti-fall tool can prevent the downhole instrument from falling into the well, and at the same time can eliminate the problem of worse danger caused by lifting the downhole instrument; the use of the downhole instrument anti-fall tool can improve the subsequent redundant workload caused by the complication of the accident, and 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] For further reference, Figure 1The fastener 100 includes a pressing plate 110, which is provided with a plurality of threaded holes, and a limiting groove is provided on the surface of the pressing plate 110 from one end to the other end; the pressing plate 110 is provided with two pieces, the two pressing plates 110 are symmetrically distributed, and are connected by bolts passing through the threaded holes, so that the two limiting grooves enclose a wire hole.

[0055] Specifically, the steel cable is brought into contact with the groove surface of the limit groove, and the distance between the two pressing plates 110 can be adjusted by bolts. By utilizing the compressibility of the steel cable, the two pressing plates 110 and the steel cable will be fitted in an interference fit manner to achieve locking of the steel cable. With this design, the fastener 100 and the steel cable are simply locked, easy to operate, and time can be saved.

[0056] For further reference, Figure 1 and Figure 2 The supporting ring 300 includes a threading platform 310 and a supporting claw 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 supporting claws 320 are distributed at intervals on the side of the threading platform 310 and are fixedly connected to the threading platform 310.

[0057] by Figure 2 For example, through the first U-shaped groove, the threading platform 310 can be quickly put on the cable, and through the support claws 320, the support ring 300 can be seated on the boss 210 without falling. In addition, the adjacent support claws 320 are spaced apart to provide a channel for the normal circulation of drilling fluid, ensuring that there is no pressure build-up during well pressure reduction, and the support ring 300 can be placed conveniently and quickly when overflow occurs.

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

[0059] Specifically, through the opening, the inner sleeve 400 can be quickly sleeved on the steel cable, and its second threaded hole cooperates with the top screw to further tighten the steel cable to prevent the steel cable from falling with the downhole instrument. In addition, it should be noted that when the inner sleeve 400 and the fastener 100 are in the outer sleeve 200, an annulus is formed between the inner sleeve 400 and the inner wall of the outer sleeve 200, ensuring the normal flow of drilling fluid.

[0060] For further reference, Figure 1 The downhole instrument anti-fall tool also includes an auxiliary platform 500, which is used to support the supporting ring 300 and is provided with an avoidance hole for passing the steel wire cable.

[0061] Continue to refer Figure 1The 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, and the opening directions of the open ring 520 and the second U-shaped groove are consistent. Here, the fracture of the open ring 520 and the second U-shaped groove are avoidance holes, through which the steel wire cable 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, when a dangerous situation occurs, the two pressing plates 110 can complete the locking of the steel cable on the support platform 510, and the support platform 510 plays an auxiliary role; the composition of the auxiliary platform 500 structure ensures that the overflow slurry is not blocked when facing a dangerous situation, and the operation is safe and reliable. After the two pressing plates 110 complete the locking operation on the auxiliary platform 500, the auxiliary platform 500 is removed, and the steel cable is tested to determine whether the steel cable is locked. After confirming that it is locked, the steel cable is cut, and the broken ends of the steel cable are sorted, and then the outer sleeve 200 is put in, and the outer sleeve 200 is connected to the joint of the anti-blowout cock, so that the on-site operation is completed.

[0063] For further reference, Figure 2 The end of the outer sleeve 200 with the tapered hole is provided with an internal thread for threaded connection with the anti-blowout cock; the end of the outer sleeve 200 with the second straight hole is provided with an external thread for threaded connection with the stuck drill. From one end to the other end of the outer sleeve 200, the channel of the outer sleeve 200 is divided into a tapered hole, a first straight hole and a second straight hole in sequence; the small end of the tapered 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 tapered hole.

[0064] Continue to refer Figure 2 The design of the two ends of the outer sleeve 200 enables the outer sleeve 200 to be quickly connected to the drilling tool and the anti-blowout cock; the design of the tapered hole forms a chamfer at the upper end of the outer sleeve 200, which is convenient for placing the supporting ring 300; the connection between the first straight hole and the second straight hole forms a boss 210, and the boss 210 is close to the lower end of the outer sleeve 200. In this way, when the wire cable is cut, there is a certain space in the outer sleeve 200 to hold the broken end of the wire cable, so that the upper end thereof is better connected to the anti-blowout cock.

[0065] The present invention also provides a method for preventing a downhole instrument from falling. The method is based on the downhole instrument from falling and comprises the following steps:

[0066] S100: Before drilling, the outer sleeve 200 is threadedly connected to the stuck drill bit; S200: Two pressing plates 110 are connected by bolts to compress the steel cable; S300: The support ring 300 is sleeved on the steel cable and placed on the boss 210 in the outer sleeve 200; S400: Cut the steel cable and then put the broken end of the steel cable into the outer sleeve 200; S500: The outer sleeve 200 is threadedly connected to the anti-blowout cock. In step S200, when a dangerous situation occurs, the two pressing plates 110 are connected on the auxiliary platform 500 to complete the locking of the steel cable.

[0067] The anti-fall method uses the tool to avoid the well being scrapped or the accident being further complicated due to a stuck drill, avoids 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, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 downhole instrument anti-fall tool, characterized in that: include: A fastener (100), an outer sleeve (200) and a support ring (300); The fastener (100) is used to pass the steel wire cable and is locked with the steel wire cable; The outer sleeve (200) is tubular, and a boss (210) is provided on its inner wall. The outer sleeve (200) is used to connect between the blowout prevention cock and the stuck drill bit. The supporting ring (300) is used for passing a steel cable, and is configured to fall into the outer sleeve (200) together with the fastener (100) under a falling condition, and abut between the fastener (100) and the boss (210).

2. The downhole instrument anti-fall tool according to claim 1, characterized in that: The fastener (100) comprises a pressing plate (110), a plurality of first threaded holes are provided on the pressing plate (110), and a limiting groove is provided on the surface of the pressing plate (110) from one end to the other end of the pressing plate (110); Two pressing plates (110) are provided, and the two pressing plates (110) are symmetrically distributed and connected by bolts passing through the first threaded holes, so that the two limiting grooves are enclosed to form a wire passing hole.

3. The downhole instrument anti-fall tool according to claim 1, characterized in that: From one end to the other end of the outer sleeve (200), the hole of the outer sleeve (200) is divided into a tapered hole, a first straight hole, and a second straight hole in sequence; The small end of the tapered 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 tapered hole.

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

5. The downhole instrument anti-fall tool according to claim 1, characterized in that: The supporting ring (300) comprises a threading platform (310) and a supporting claw (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 distributed at intervals on the side of the threading platform (310) and are fixedly connected to the threading platform (310).

6. 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, and a second threaded hole is provided on its side wall, and an opening is also provided on its side wall from one end to the other end of the inner sleeve (400); The two ends of the inner sleeve (400) are used to abut against the fastener (100) and the supporting ring (300) respectively.

7. The downhole instrument anti-fall tool according to any one of claims 1 to 6, characterized in that: The downhole instrument anti-fall tool further comprises an auxiliary platform (500), wherein the auxiliary platform (500) is used to support the supporting ring (300) and is provided with an avoidance hole for passing a steel cable.

8. The downhole instrument anti-fall tool according to claim 7, characterized in that: The auxiliary platform (500) comprises 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 opening directions of the open ring (520) and the second U-shaped groove are consistent; A plurality of 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).

9. A method for preventing a downhole instrument from falling, characterized in that: The downhole instrument anti-fall tool according to any one of claims 1 to 8 comprises the following steps: S100: Before drilling, the outer sleeve (200) is threadedly connected to the stuck drill bit; S200: Connect the two pressing plates (110) by bolts to compress the steel wire cable; S300: Sleeve the supporting ring (300) on the steel cable and place it on the boss (210) inside the outer sleeve (200); S400: Cut the steel wire cable, and then put the broken end of the steel wire cable into the outer sleeve (200); S500: The outer sleeve (200) is threadedly connected to the anti-blowout cock.

10. The method for preventing downhole instrument from falling according to claim 9, characterized in that: In step S200, when a dangerous situation occurs, the two pressing plates (110) are connected on the auxiliary platform (500) to complete the locking of the steel cable.

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