A short joint for removing cuttings during tripping out, a drill string assembly and a usage method

Abstract

The present invention relates to a short section for removing cuttings during tripping out, a drill string assembly and a usage method, which includes a body, a sand settling cylinder and a sliding sleeve sequentially arranged inside the body. An upper sub is provided at the left end of the body, and a lower sub is provided at the right end. The sand settling cylinder is slidably connected to the body and detachably connected to the sliding sleeve. A sand settling cavity is formed along the side wall of the sand settling cylinder, and a cylindrical key is provided on its side wall. One end of the cylindrical key close to the body is provided with a compression spring. A sand settling cylinder flow channel is provided at the center of the sand settling cylinder. The length of the sand settling cavity is the same as the side wall of the sand settling cylinder, and the depth of the sand settling cavity is the same as the thickness of the side wall of the sand settling cylinder. A setting seat is provided at the upper end of the sliding sleeve, a fixed groove is provided on the side wall facing the sand settling cylinder, and a central flow channel is provided at the center. The diameter of the central flow channel is the same as that of the sand settling cylinder flow channel. A liquid suction hole corresponding to the sand settling cavity is also provided on the body. The structure of the present invention is simple and convenient to use.

Description

Technical Field

[0001] The present invention belongs to the technical field of drilling, and particularly relates to a sub-section, a drill string combination and a use method capable of removing cuttings during tripping out of the hole. Background Art

[0002] During the drilling process, solid particles in the wellbore are affected by gravity, viscous resistance, impact force, and buoyancy. When the concentration of cuttings is greater than the working capacity of these forces, the cuttings will settle to form a cutting bed, which seriously affects the mechanical drilling rate. During drilling, the resistance increases, especially in directional wells and horizontal wells, where downhole pressure release is likely to occur, resulting in no drilling pressure at the bit, no footage for a long time, slow progress of the project, and increased drilling costs; the cutting bed causes an increase in the torque of the drill string, and in severe cases, even breaks the drill string in the well, resulting in serious downhole accidents; the cutting bed is also the main cause of drill pipe sticking, and the presence of the cutting bed blocks the lower part of the testing tool.

[0003] Currently, the methods for removing the cutting bed mainly include: ① increasing the return velocity method; ② improving the mud properties method; ③ mechanical removal method. In on-site construction, usually the above several methods are combined. Although it is very beneficial for cutting removal, it makes the drilling process complex. Especially for the mechanical removal method, tripping in and out of the hole must be carried out within a short time, which seriously affects the drilling efficiency. Most of the currently commonly used drill string type cutting bed removal tools are purely mechanical. They drive the external structure to break the cutting bed through the rotation of the drill string and improve the flow state of the drilling fluid, thereby removing the cuttings. When the drill string is in the sliding drilling state, the drill string type cutting bed removal tool scrapes the cutting bed while sliding, and at the same time increases the sliding friction resistance of the drill string, thus affecting the improvement of the drilling efficiency. Moreover, the existing methods for removing the cutting bed are only simple destruction, and the cuttings after destruction will inevitably settle in other places in the wellbore to form a new cutting bed. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide a sub-section for removing cuttings during tripping out of the hole, a drill string combination and a use method, which can collect downhole cuttings into the sub-section during tripping out of the hole, fundamentally remove the cuttings in the well, eliminate the cutting bed, thereby reducing the friction resistance of the drill string and increasing the mechanical drilling rate.

[0005] The technical solution of the present invention lies in:

[0006] (1) The present invention proposes a sub-section for removing cuttings during tripping out of the hole.

[0007] A sub-section for removing cuttings during tripping out of the hole includes a body, a sand settling cylinder and a sliding sleeve which are sequentially arranged inside the body. An upper joint is provided at the left end of the body, and a lower joint is provided at the right end; the sand settling cylinder is slidably connected with the body and detachably connected with the sliding sleeve;

[0008] The sand settling cylinder is provided with a sand settling cavity along its side wall, and a cylindrical key is provided on its side wall. One end of the cylindrical key close to the body is provided with a compression spring. A sand settling cylinder flow channel is provided at the center of the sand settling cylinder. The length of the sand settling cavity is the same as the side wall of the sand settling cylinder, and the depth of the sand settling cavity is the same as the thickness of the side wall of the sand settling cylinder.

[0009] A seating seat is provided at the upper end of the sliding sleeve. A fixed groove is provided on one side of the side wall facing the sand settling cylinder, and a central flow channel is provided at the center. The diameter of the central flow channel is the same as that of the sand settling cylinder flow channel.

[0010] A liquid suction hole is also provided on the body corresponding to the sand settling cavity.

[0011] The outer diameter of the sand settling cylinder is the same as the inner diameter of the body, and the inner diameter is the same as the outer diameter of the sliding sleeve.

[0012] The sand settling cylinder is connected to the body by a thread, and the sliding sleeve is connected to the sand settling cylinder by a shear pin at the left end of the sand settling cylinder.

[0013] The diameter of the fixed groove is larger than the diameter of the cylindrical key, and the depth of the fixed groove is less than the length of the cylindrical key.

[0014] The upper sub is of the drill pipe female connection type, and the lower sub is of the drill pipe male connection type.

[0015] (2) The present invention provides a drill string assembly for removing cuttings during tripping out.

[0016] A drill string assembly for removing cuttings during tripping out includes any one of the above-mentioned short joints for removing cuttings during tripping out, and stabilizers are respectively connected to both ends of the short joint for removing cuttings during tripping out.

[0017] The stabilizing bars of the stabilizer are straight edges or spiral edges.

[0018] (3) The present invention provides a method for using a drill string assembly for removing cuttings during tripping out.

[0019] A method for using a drill string assembly for removing cuttings during tripping out, using the above drill string assembly for removing cuttings during tripping out, the specific use process is as follows:

[0020] S1: When tripping out is required, a setting tool is dropped into the drill pipe from the wellhead. The setting tool is guided by a guide head and reaches the seating seat for setting under the drive of the drilling fluid. At this time, the rubber seal of the setting tool blocks the central flow channel, the pressure builds up inside the body, the shear pin is cut off, the sliding sleeve moves to the right along the sand settling cylinder until the right end face of the sliding sleeve contacts the right end face of the sand settling cylinder. At this time, the cylindrical key is opposite to the center of the fixed groove, the compression spring extends, the cylindrical key is stuck into the fixed groove, and the sliding sleeve and the sand settling cylinder are fixed. At this time, the liquid suction hole, the sand settling cavity and the inside of the body form an open loop.

[0021] S2: At this time, the surface process is switched, the mud pump is started, and the mud is pumped from inside the drill pipe at a low displacement. At the same time, the rotary table is started to slowly rotate the drill string. The cuttings in the annulus are driven by the mud, enter the sand settling barrel through the liquid suction holes, and settle in the sand settling barrel, so as to completely remove the cuttings after the cuttings bed in the wellbore is destroyed during the tripping out process.

[0022] The displacement of the mud pump is less than or equal to 20 L / min, and the rotational speed of the drill string is 10 r / min.

[0023] The technical effect of the present invention is as follows:

[0024] The present invention has a simple structure and is easy to use. It can collect downhole cuttings into the short joint during the tripping out process, fundamentally remove the cuttings in the well, eliminate the cuttings bed, thereby reducing the friction resistance of the drill string and increasing the rate of penetration. Description of the Drawings

[0025] Figure 1 Schematic diagram of the structure of a short joint for removing cuttings during tripping out (during normal drilling).

[0026] Figure 2 Sectional view of the structure of a short joint for removing cuttings during tripping out (in the normal drilling state).

[0027] Figure 3 A-A sectional view of a short joint for removing cuttings during tripping out.

[0028] Figure 4 B-B sectional view of a short joint for removing cuttings during tripping out.

[0029] Figure 5 Schematic diagram of the structure of a short joint for removing cuttings during tripping out (when removing cuttings during tripping out).

[0030] Figure 6 Sectional view of the structure of a short joint for removing cuttings during tripping out (when removing cuttings during tripping out).

[0031] Figure 7 Schematic diagram of the structure of a drill string for removing cuttings during tripping out.

[0032] Reference numerals: 1, upper sub; 2, body; 3, setting seat; 4, shear pin; 5, sand settling barrel; 6, sliding sleeve; 7, central flow path; 8, fixed groove; 9, compression spring; 10, cylindrical key; 11, sand settling barrel flow path; 12, lower sub; 13, sand settling cavity; 14, liquid suction hole; 15 - rubber seal; 16 - guide head; 17 - stabilizer. Detailed Description of the Invention

[0033] The present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0034] Embodiment 1

[0035] A short section for removing cuttings during tripping out, comprising a body 2, a sand settling cylinder 5 and a sliding sleeve 6 which are sequentially arranged inside the body 2. An upper sub 1 is provided at the left end of the body 2, and a lower sub 12 is provided at the right end. The sand settling cylinder 5 is slidably connected to the body 2 and detachably connected to the sliding sleeve 6. A sand settling chamber 13 is formed along the side wall of the sand settling cylinder 5, and a cylindrical key 10 is provided on its side wall. A compression spring 9 is provided at one end of the cylindrical key 10 close to the body 2. A flow channel of the sand settling cylinder 5 is provided at the center of the sand settling cylinder 5. The length of the sand settling chamber 13 is the same as the side wall of the sand settling cylinder 5, and the depth of the sand settling chamber 13 is the same as the thickness of the side wall of the sand settling cylinder 5. A liquid suction hole is also provided on the body 2 corresponding to the sand settling chamber 13.

[0036] Example 2

[0037] On the basis of Example 1, it further includes: The outer diameter of the sand settling cylinder 5 is the same as the inner diameter of the body 2, and the inner diameter is the same as the outer diameter of the sliding sleeve 6. The sand settling cylinder 5 is connected to the body 2 by threads, and the sliding sleeve 6 is connected to the sand settling cylinder 5 by a shear pin 4 at the left end of the sand settling cylinder 5. The diameter of the fixed groove 8 is larger than the diameter of the cylindrical key 10, and the depth of the fixed groove 8 is smaller than the length of the cylindrical key 10. The upper sub 1 is of the female drill pipe coupling type, and the lower sub 12 is of the male drill pipe coupling type.

[0038] Example 3

[0039] A drill string assembly for removing cuttings during tripping out, comprising any one of the above short sections for removing cuttings during tripping out, and stabilizers 17 are respectively connected to both ends of the short section for removing cuttings during tripping out. The stabilizing bars of the stabilizers 17 are straight edges or spiral edges.

[0040] Example 4

[0041] A method for using a drill string assembly for removing cuttings during tripping, using the drill string assembly for removing cuttings during tripping as described above. The specific usage process is as follows: S1: When tripping is to be carried out, a setting tool is dropped into the drill pipe from the wellhead. The setting tool is guided by the guide head 16 and reaches the setting seat 3 under the drive of the drilling fluid for setting. At this time, the rubber seal body 15 of the setting tool blocks the central flow channel 7, and the pressure builds up inside the body 2. The shear pin 4 is cut off, and the sliding sleeve 6 moves to the right along the sand settling cylinder 5 until the right end face of the sliding sleeve 6 contacts the right end face of the sand settling cylinder 5. At this time, the center of the cylindrical key 10 is opposite to the center of the fixed groove 8, the compression spring 9 extends, and the cylindrical key 10 is engaged in the fixed groove 8. The sliding sleeve 6 and the sand settling cylinder 5 are fixed. At this time, the liquid suction hole forms an open loop with the sand settling cavity 13 and the inside of the body 2; S2: At this time, the surface flow path is switched, the drilling fluid pump is started, and the drilling fluid is pumped out from the drill pipe at a low displacement. At the same time, the rotary table is started to slowly rotate the drill string. The cuttings in the annulus are driven by the drilling fluid, enter the sand settling cylinder 5 through the liquid suction hole, and settle in the sand settling cylinder 5, so as to completely remove the cuttings after the cutting bed in the wellbore is destroyed during tripping.

[0042] The displacement of the drilling fluid pump is less than or equal to 20 L / min, and the rotation speed of the drill string is 10 r / min.

Claims

1. A drill pipe assembly for removing cuttings during tripping, comprising a short joint for removing cuttings during tripping and stabilizers (17) respectively connected to both ends thereof; the short joint for removing cuttings during tripping includes a body (2), a sand settling cylinder (5) and a sliding sleeve (6) sequentially arranged inside the body (2), an upper sub (1) is provided at the left end of the body (2), and a lower sub (12) is provided at the right end; the sand settling cylinder (5) is slidably connected or threadedly connected to the body (2) and is detachably connected to the sliding sleeve (6); characterized in that: The sand settling cylinder (5) is provided with a sand settling cavity (13) along its side wall, and a cylindrical key (10) is provided on its side wall. A compression spring (9) is provided at one end of the cylindrical key (10) close to the body (2). A flow channel of the sand settling cylinder (5) is provided at the center of the sand settling cylinder (5). The length of the sand settling cavity (13) is the same as the side wall of the sand settling cylinder (5), and the depth of the sand settling cavity (13) is the same as the thickness of the side wall of the sand settling cylinder (5); A setting seat (3) is provided at the upper end of the sliding sleeve (6), a fixed groove (8) is provided on the side wall facing the sand settling cylinder (5), and a central flow channel (7) is provided at the center; The diameter of the central flow channel (7) is the same as that of the flow channel of the sand settling cylinder (5); A liquid suction hole is also provided on the body (2) corresponding to the sand settling cavity (13). The outer diameter of the sand settling cylinder (5) is the same as the inner diameter of the body (2), and the inner diameter is the same as the outer diameter of the sliding sleeve (6). The sliding sleeve (6) and the sand settling cylinder (5) are connected by a shear pin (4) at the left end of the sand settling cylinder (5). The specific usage process is as follows: S1: When pulling out the drill string, a setting tool is dropped into the drill pipe from the wellhead. The setting tool is guided by a guide head (16) and reaches the setting seat (3) for setting under the drive of the drilling fluid. At this time, the rubber seal (15) of the setting tool blocks the central flow channel (7), the pressure in the body (2) is built up, the shear pin (4) is cut off, and the sliding sleeve (6) moves to the right along the sand settling cylinder (5) until the right end face of the sliding sleeve (6) contacts the right end face of the sand settling cylinder (5). At this time, the center of the cylindrical key (10) is opposite to the fixed groove (8), the compression spring (9) extends, and the cylindrical key (10) is clamped into the fixed groove (8). The sliding sleeve (6) and the sand settling cylinder (5) are fixed. At this time, the liquid suction hole, the sand settling cavity (13) and the inside of the body (2) form an open loop; S2: At this time, the surface process is switched, the drilling fluid pump is started, and the drilling fluid is pumped from the drill pipe at a low displacement. At the same time, the rotary table is started to rotate the drill string slowly. The cuttings in the annulus are driven by the drilling fluid, enter the sand settling cylinder (5) through the liquid suction hole and settle in the sand settling cylinder (5), so as to completely remove the cuttings after the cutting bed in the wellbore is damaged during the process of pulling out the drill string.

2. The drill string assembly for removing cuttings during tripping according to claim 1, wherein: The diameter of the fixed groove (8) is larger than the diameter of the cylindrical key (10), and the depth of the fixed groove (8) is smaller than the length of the cylindrical key (10).

3. The drill string assembly for removing cuttings during tripping as claimed in claim 2, wherein: The upper sub (1) is of the female drill pipe connection type, and the lower sub (12) is of the male drill pipe connection type.

4. The drill string assembly for removing cuttings during tripping out according to claim 3, characterized in that: The displacement of the drilling fluid pump is less than or equal to 20 L / min, and the rotation speed of the drill string is 10 r / min.

5. The drill pipe string assembly for removing cuttings during tripping out according to claim 4, characterized in that: The stabilizing bars of the stabilizer (17) are straight edges or spiral edges.

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