Wear band assembly for near-bit instrument and near-bit instrument

Abstract

The present application relates to a kind of wear-resistant band assemblies suitable for near-bit instrument, wear-resistant band assemblies include: first wear-resistant band, it is annular structure, by laser cladding at the first end of circuit skeleton, the first end of circuit skeleton is connected with motor;Second wear-resistant band, also annular structure, by laser cladding at the second end of circuit skeleton, the second end of circuit skeleton is connected with the first end of the casing;Third wear-resistant band, it is helical wear-resistant band, by laser cladding on the wall of casing, the second end of casing is connected with the first end of casing fixed double female, the second end of casing fixed double female is connected with drill bit.The wear-resistant band includes adding a place annular wear-resistant band on circuit skeleton, a long helical wear-resistant band is designed on casing, the helical direction is right-handed form, consistent with the direction of rotation when instrument drilling, wear-resistant band surface is polished, can reduce the resistance when contact with well wall.

Description

Technical Field

[0001] This invention relates to a wear-resistant belt assembly and a near-bit instrument, belonging to the field of drilling technology. Background Technology

[0002] As drilling equipment adapted for hard formations, near-bit instruments require continuous drilling through these formations to reach the oil reservoir. Therefore, the instruments themselves demand high strength, hence the inclusion of wear-resistant bands. However, the original instruments only had a single annular wear-resistant band at the circuit frame, avoiding the cover plate. The initial design consideration was that with the drill bit at the bottom and the wear-resistant band at the top, it would be sufficient to protect the entire instrument and reduce friction between the instrument body and the wellbore during operation.

[0003] However, observation of the returned instruments from actual drilling revealed the following: the double-nut retainer on the barrel showed severe wear at its connection to the circuit frame; the lower end of the barrel showed more severe wear, while the upper end showed slightly less wear; the copper ring, data port cover, power port cover, and pressure cap all exhibited varying degrees of wear; the wear on the wear-resistant strip differed significantly between the upper and lower ends, with the lower end showing more severe wear than the upper end. This wear on the instrument has severely impacted the usability of the double-nut retainer, copper ring, barrel, and cover. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a wear-resistant belt assembly and a near-drill-bit instrument suitable for near-drill-bit instruments. The wear-resistant belt includes an annular wear-resistant belt added to the circuit skeleton and a long spiral wear-resistant belt designed on the cylinder. The spiral direction is right-handed, consistent with the rotation direction of the instrument during drilling. The surface of the wear-resistant belt is polished to reduce the resistance generated when in contact with the well wall.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A wear-resistant belt assembly for near-bit instruments, the wear-resistant belt assembly being laser-clad onto the near-bit instrument, the near-bit instrument including a retainer and circuit frames and retainer fixing double nuts located at both ends of the retainer, the wear-resistant belt assembly comprising:

[0007] The first wear-resistant belt is a ring structure and is laser-clad onto the first end near the first end of the circuit frame, the first end of which is connected to the motor.

[0008] The second wear-resistant strip, also a ring structure, is laser-clad onto the second end near the circuit skeleton, and the second end of the circuit skeleton is connected to the first end of the sleeve.

[0009] The third wear-resistant belt is a spiral wear-resistant belt, which is laser-fused onto the wall of the barrel. The second end of the barrel is connected to the first end of the barrel fixing nut, and the second end of the barrel fixing nut is connected to the drill bit.

[0010] Preferably, the wear-resistant belt assembly for near-drill bit instruments is provided with a transmission coil, a data port cover, a power port cover, and a pressure cap on the circuit frame, wherein the first wear-resistant belt and the second wear-resistant belt avoid the transmission coil, the data port cover, the power port cover, and the pressure cap during laser cladding.

[0011] The wear-resistant belt assembly for near-drill bit instruments, preferably, includes a third wear-resistant belt comprising several spiral belts evenly distributed on the wall of the barrel, wherein the spiral direction of the spiral belts is right-handed.

[0012] The wear-resistant belt assembly for near-drill bit instruments, preferably, has a spiral belt pitch of 1500-2500 mm and a height of 300-600 mm.

[0013] Preferably, the wear-resistant belt assembly for near-drill bit instruments is made primarily of cemented carbide.

[0014] The wear-resistant belt assembly for near-drill bit instruments, preferably, is composed mainly of nickel-based tungsten carbide particles, with a content of 40wt-70wt%.

[0015] A second aspect of the present invention provides a near-drill bit instrument comprising the wear-resistant belt assembly described in any one of the preceding claims.

[0016] The present invention has the following advantages due to the adoption of the above technical solutions:

[0017] This invention incorporates a ring-shaped wear-resistant strip on the circuit frame, avoiding the cover plate and groove. This allows the wear-resistant strip to act as two fulcrums when the instrument is under pressure, bending, and in contact with the well wall, effectively preventing contact between the circuit frame substrate and the well wall. A long spiral wear-resistant strip is designed on the gripper, with a right-hand spiral direction consistent with the instrument's rotation during drilling. The surface of this wear-resistant strip is polished to reduce resistance upon contact with the well wall. The long spiral wear-resistant strip on the gripper essentially prevents contact between the gripper substrate and the well wall; combined with the wear-resistant strip on the circuit frame, this effectively ensures that the entire instrument substrate does not contact the well wall. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the wear-resistant belt structure of a conventional instrument and the wear condition of parts after actual drilling, provided as an embodiment of the present invention;

[0019] Figure 2A schematic diagram of an improved near-bit instrument wear-resistant belt assembly and a near-bit instrument provided in another embodiment of the present invention;

[0020] Figure 3 a is Figure 2 Sectional view of AA, Figure 3 b is Figure 2 Sectional view of BB;

[0021] Figure 4 for Figure 2 Sectional view of CC;

[0022] The markings in the diagram are as follows:

[0023] 1-Circuit frame; 2-Cylinder; 3-Transmission coil; 4-Cylinder fixing plate; 5-Data port cover; 6-Power port cover; 7-Clad cover; 8-Cylinder fixing double female; 9-Copper ring; 10-First wear-resistant belt; 11-Second wear-resistant belt; 12-Third wear-resistant belt. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," "third," "fourth," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0026] This invention addresses the problem in existing near-bit drilling instruments where the lower end of the gripper experiences severe wear, while the upper end shows slightly less wear. The copper ring, data port cover, power port cover, and pressure cap all exhibit varying degrees of wear, and the wear resistance band shows a significant difference between the upper and lower ends, with the lower end showing more severe wear. The invention provides a wear resistance band assembly adapted for hard formations in near-bit drilling instruments. This assembly incorporates a ring-shaped wear resistance band design on the circuit frame, avoiding the cover plate and groove. This allows the circuit frame wear resistance band to act as two fulcrums when the instrument is under pressure, bending, and in contact with the wellbore, preventing contact between the circuit frame substrate and the wellbore. A long spiral wear resistance band is designed on the gripper, with a right-hand spiral direction consistent with the instrument's rotation direction during drilling. The surface of the wear resistance band is polished to reduce resistance during contact with the wellbore.

[0027] The technical solution of the invention will now be described in detail with reference to the accompanying drawings.

[0028] like Figure 1 As shown, existing near-bit instruments only have a single annular wear-resistant strip (i.e., the first wear-resistant strip 10) designed at the circuit frame 1. The wear-resistant strip avoids the data port cover 5 and the power port cover 6. The initial consideration for this design was that the instrument has a drill bit at the bottom with a diameter of 215.9 mm, and a wear-resistant strip at the top with a diameter of 190.8 mm, which is sufficient to protect the entire instrument and reduce friction between the instrument base and the well wall during operation.

[0029] However, observation of the returned instruments from actual drilling revealed the following: the wear at the connection point between the retainer 2 and the circuit frame 1 was severe; the second end of the retainer 2 was more severely worn, while the first end was slightly less worn; the copper ring 9, data port cover 5, power port cover 6, and pressure cap 7 all exhibited varying degrees of wear; the wear on the first and second ends of the wear-resistant band (i.e., the first wear-resistant band 10) differed significantly, with the second end showing more severe wear than the first. This wear on the instrument has severely impacted the usability of the retainer fixing the double female 8, copper ring 9, retainer 2, and the covers (data port cover 5 and power port cover 6).

[0030] Analysis revealed that the instrument was bent under pressure during directional drilling, and the entire instrument was pressed tightly against the well wall. The original wear-resistant zone (i.e., the first wear-resistant zone 10) could be considered as a fulcrum, which could not guarantee that the entire instrument body would not contact the well wall when the instrument was bent. After being driven by the motor, the instrument rotated at a faster speed, and repeated contact and friction with the well wall in the hard formation caused severe wear of the entire instrument body.

[0031] The improved wear-resistant belt assembly structure is as follows: Figure 2As shown, an annular wear-resistant strip (i.e., the second wear-resistant strip 11) is added to the circuit frame 1. The second wear-resistant strip 11 avoids the cover plates (data port cover plate 5, power port cover plate 6) and the groove. In this way, when the instrument is subjected to pressure and bending and comes into contact with the well wall, the wear-resistant strips (the first wear-resistant strip 10 and the second wear-resistant strip 11) on the circuit frame 1 can be regarded as two fulcrums, preventing the base of the circuit frame 1 from contacting the well wall. A long spiral wear-resistant strip (i.e., the third wear-resistant strip 12) is designed on the barrel 2. The spiral direction is right-handed, which is consistent with the rotation direction of the instrument during drilling. The surface of the wear-resistant strip assembly is polished to reduce the resistance generated when in contact with the well wall. The long spiral wear-resistant strip (the third wear-resistant strip 12) on the barrel 2 can basically prevent the base of the barrel 2 from contacting the well wall. With the wear-resistant strips (the first wear-resistant strip 10 and the second wear-resistant strip 11) of the circuit frame 1, it can be basically ensured that the base of the entire instrument does not come into contact with the well wall.

[0032] Specifically, the cross-sectional view of the wear-resistant strip on circuit frame 1 is as follows: Figure 3 As shown in the figure, the section with denser cross-section lines is the wear-resistant strip after laser cladding. The two annular wear-resistant strips (first wear-resistant strip 10 and second wear-resistant strip 11) are cleverly designed to avoid the data port cover 5, the power port cover 6, and the pressure cover 7. They provide good protection for the circuit frame 1, the transmission coil 3, the coil fixing plate 4, the data port cover 5, the power port cover 6, and the pressure cover 7.

[0033] The main feature of the wear-resistant belt design on the gripper 2 is a spiral laser-clad wear-resistant belt. The spiral pitch is designed to be 2000mm and the height is 445mm, with the specific pitch and height depending on the dimensions of the gripper 2. The spiral direction is right-handed, following the drilling direction of the instrument. Considering that the gripper 2 may deform under high-temperature cladding, the wear-resistant belt design covers most of the gripper 2, avoiding the sealing surface, thus improving the process and reducing the impact of deformation. The surface of the wear-resistant belt after laser cladding is polished to reduce surface roughness and minimize wear between the instrument and the well wall during drilling. The wear-resistant belt assembly is preferably made of cemented carbide, with the main component being nickel-based tungsten carbide particles, with a content of 40wt-70wt%.

[0034] The existing near-drill bit instrument design lacks a wear-resistant band on the retainer 2, with only a ring-shaped wear-resistant band on the circuit frame 1 at section B. Field measurements revealed significant wear on the retainer fixing double nuts 8 near retainer 2, severe wear on retainer 2 itself, and varying degrees of wear on the circuit frame 1, transmission coil 3, coil fixing 4, data port cover 5, power port cover 6, and pressure cap 7, affecting normal instrument operation. This application, after improving the wear-resistant band design, has received feedback from users under the same operating conditions: the entire instrument structure shows no wear, parts exhibit only normal use signs and no wear marks, and the wear-resistant band shows only slight wear, which is considered normal. Therefore, this design effectively protects the entire instrument, enhances its wear resistance, and extends its service life.

[0035] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wear-resistant belt assembly for a near-bit instrument, the wear-resistant belt assembly being laser-clad onto the near-bit instrument, the near-bit instrument comprising a retainer (2) and circuit frame (1) located at both ends of the retainer (2) and retainer fixing double nuts (8), characterized in that, The wear-resistant belt assembly includes: The first wear-resistant strip (10) is a ring structure and is laser-fused onto the circuit frame (1). The first wear-resistant strip (10) is close to the first end of the circuit frame (1), and the first end of the circuit frame (1) is connected to the motor. The second wear-resistant strip (11) is also a ring structure. It is laser-fused onto the circuit skeleton (1). The second wear-resistant strip (11) is close to the second end of the circuit skeleton (1). The second end of the circuit skeleton (1) is connected to the first end of the sleeve (2). The third wear-resistant belt (12) is a spiral wear-resistant belt, which is laser-fused onto the wall of the cylinder (2). The second end of the cylinder (2) is connected to the first end of the cylinder fixing double nut (8), and the second end of the cylinder fixing double nut (8) is connected to the drill bit.

2. The wear-resistant belt assembly for near-drill bit instruments according to claim 1, characterized in that, The circuit frame (1) is provided with a transmission coil (3), a data port cover (5), a power port cover (6) and a pressure cover (7). The first wear-resistant strip (10) and the second wear-resistant strip (11) avoid the transmission coil (3), the data port cover (5), the power port cover (6) and the pressure cover (7) during laser cladding.

3. The wear-resistant belt assembly for near-drill bit instruments according to claim 1, characterized in that, The third wear-resistant belt (12) includes several spiral belts evenly distributed on the wall of the sleeve (2), and the spiral direction of the spiral belts is right-handed.

4. The wear-resistant belt assembly for near-drill bit instruments according to claim 3, characterized in that, The pitch of the spiral ribbon is 1500-2500mm, and the height is 300-600mm.

5. The wear-resistant belt assembly for near-drill bit instruments according to claim 1, characterized in that, The wear-resistant belt assembly is mainly made of cemented carbide.

6. The wear-resistant belt assembly for near-drill bit instruments according to claim 5, characterized in that, The main component of the cemented carbide is nickel-based tungsten carbide particles, with a content of 40wt-70wt%.

7. A near-drill bit instrument, characterized in that, Includes the wear-resistant belt assembly as described in any one of claims 1-6.

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