Gas well production channel reconstruction device and reconstruction method

Abstract

The gas well production channel reconstruction device comprises a continuous oil pipe and a whipstock connected into the oil pipe, a flexible drill rod is connected to the lower portion of the continuous oil pipe, the flexible drill rod is bent, the other end of the flexible drill rod faces the side wall of the oil pipe, and a hydraulic motor is connected to the end, facing the side wall of the oil pipe, of the flexible drill rod. An output shaft of the hydraulic motor is connected with a milling cone, a drill bit portion of the milling cone faces the side wall of the oil pipe, and the flexible drill rod is a hollow pipeline. The pump truck is used for pressing the interior of the continuous oil pipe to drive the hydraulic motor to rotate, so that the milling cone is driven to rotate, impact force is generated on the wall of the oil pipe, when the drilling and grinding time reaches a certain value, the oil pipe is drilled through, a new airflow channel is generated, and a gas well is reopened for production. The processes of milling and trepanning are realized through one-time operation; the flexible drill rod is bent through the whipstock, so that the milling cone is moved to further penetrate into the side wall of the oil pipe for punching.

Description

Technical Field

[0001] The present invention belongs to the technical field of downhole operation in production, and particularly relates to a device and method for reconstructing a production channel of a gas well. Background Art

[0002] At present, there are a large number of throttler wells in use in oilfields, and there are many throttler manufacturers. Affected by various factors such as the type of throttler and the limitation of fishing methods, the fishing success rate of throttlers is not high. In some wells, the throttler falls into the bottom of the well during fishing and cannot be fished out, blocking the gas flow channel, resulting in a serious decline in the gas well production or even shut-down. The traditional method is to pull out the tubing 3 and remove the throttler 12, which has problems such as long operation cycle, large operation workload, and high operation cost. Summary of the Invention

[0003] The purpose of the present invention is to provide a device and method for reconstructing a production channel of a gas well to solve the problem that the production channel of the tubing is blocked and the gas well is shut down due to the throttler falling into the well.

[0004] The purpose of the present invention is achieved by the following technical means. A device for reconstructing a production channel of a gas well includes a coiled tubing and a whipstock connected inside the tubing. A flexible drill pipe is connected below the coiled tubing. The flexible drill pipe is bent, and the other end faces the tubing side wall. A hydraulic motor is connected to the end of the flexible drill pipe facing the tubing side wall. The output shaft of the hydraulic motor is connected with a milling cone, and the drill head of the milling cone faces the tubing side wall. The flexible drill pipe is a hollow pipe.

[0005] It also includes a bridge plug, which is connected inside the tubing, and the whipstock is connected above the bridge plug.

[0006] The whipstock is an inclined platform with a downwardly inclined upper surface.

[0007] A downwardly concave flexible drill pipe groove is also formed on the upper surface of the whipstock, and the width of the flexible drill pipe groove matches that of the flexible drill pipe.

[0008] The cross-section of the flexible drill pipe groove is triangular, and the bottom edge of the flexible drill pipe groove faces the tubing side wall.

[0009] A method for reconstructing a production channel of a gas well includes the following steps:

[0010] Lower the bridge plug into the tubing to the position where the production channel needs to be drilled and fixed in the tubing; lower the whipstock above the bridge plug;

[0011] Lower the coiled tubing, flexible drill pipe, hydraulic motor and milling cone. The bent part of the flexible drill pipe contacts the upper surface of the whipstock, and the milling cone points to the tubing side wall;

[0012] Pressurize the coiled tubing on the ground to drive the hydraulic motor and the milling cone to rotate and drill holes in the tubing side wall;

[0013] Lower the coiled tubing further. During the lowering process, the flexible drill pipe bends further, the length of the vertical part decreases, and the length of the horizontal part increases. Push the milling cone further towards the sidewall of the tubing, so that the milling cone further grinds the drilled hole along the previously drilled hole until the sidewall of the tubing is drilled through, generating a new gas flow production channel. Stop the pressure pumping on the ground, and pull out the coiled tubing, flexible drill pipe, hydraulic motor, and milling cone.

[0014] When lowering the coiled tubing, insert the flexible drill pipe into the flexible drill pipe groove to fix the position of the flexible drill pipe.

[0015] The lowering speed of the coiled tubing is less than 600 m / h.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. By pumping pressure into the coiled tubing through a pump truck, drive the hydraulic motor to rotate, thereby driving the milling cone to rotate, and at the same time generating an impact force on the tubing wall. When the drilling and grinding time reaches a certain value, drill through the tubing to generate a new gas flow channel, realizing the restart of gas well production. One trip operation realizes the processes of milling and opening holes.

[0018] 2. Bend the flexible drill pipe through the whipstock, so that the position of the milling cone moves and further drills holes into the sidewall of the tubing. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of a gas well production channel reconstruction device;

[0020] Figure 2 It is a schematic structural diagram of the whipstock;

[0021] Figure 3 It is a schematic diagram of the change of the flexible drill pipe when the coiled tubing is lowered;

[0022] In the figure, 1 is the coiled tubing; 2 is the whipstock; 3 is the tubing; 4 is the flexible drill pipe; 5 is the bridge plug; 6 is the hydraulic motor; 7 is the milling cone; 8 is the flexible drill pipe groove; 9 is the casing; 10 is the hydraulic anchor; 11 is the packer; 12 is the restrictor; 13 is the ball seat; 14 is the artificial bottom hole;

[0023] The present invention will be further described in detail below with reference to the drawings and embodiments. Specific Embodiments

[0024]

Embodiment 1

[0025] As Figure 1As shown, a gas well production channel reconstruction device includes a coiled tubing 1 and a whipstock 2 connected to the tubing 3. A flexible drill rod 4 is connected below the coiled tubing 1, wherein the flexible drill rod 4 is bent and the other end faces the side wall of the tubing 3. A hydraulic motor 6 is connected to the end of the flexible drill rod 4 facing the side wall of the tubing 3. The output shaft of the hydraulic motor 6 is connected to a milling cone 7. The drill head of the milling cone 7 faces the side wall of the tubing 3. The flexible drill rod 4 is a hollow pipe.

[0026] If Figure 1 As shown in , the existing oil pipe 3 is provided with a casing 9 and an artificial well bottom 14 outside, a throttle 12 and a ball seat 13 at the bottom of the oil pipe 3, and a hydraulic anchor 10 and a packer 11 are often provided outside the casing 3.

[0027] The whipstock 2 is connected to the oil pipe 3, one is for positioning, the other is to provide a contact point for the flexible drill pipe 4 to bend.

[0028] The coiled tubing 1 is connected to the flexible drill pipe 4, and the lower end of the flexible drill pipe 4 is connected to the hydraulic motor 6. By pressing the coiled tubing 1 on the ground, the hydraulic motor 6 and the milling cone 7 on the output shaft are driven to rotate.

[0029] The entire flexible drill rod 4 remains bent without the influence of external force, and the lower end changes from pointing downward to pointing toward the side wall of the oil pipe 3, and the milling cone 7 rotates to drill a hole in the side wall of the oil pipe 3.

[0030] It also includes a bridge plug 5, which is connected to the oil pipe 3, and the whipstock 2 is connected above the bridge plug 5.

[0031] The bridge plug 5 provides support for the whipstock 2, fixes the bridge plug 5 in the oil pipe 3, and the whipstock 2 falls on or is connected above the bridge plug 5 to ensure that the whipstock 2 is stable and will not fall.

[0032] The incline device 2 is an inclined platform with an upper surface inclined downward.

[0033] If Figure 1 As shown in , the cross section of the whipstock 2 is triangular, and the whole is a ramp.

[0034] The upper surface of the whipstock 2 is also provided with a downwardly concave flexible drill rod groove 8, the width of which matches the flexible drill rod 4.

[0035] The cross section of the flexible drill pipe groove 8 is triangular, and the bottom edge of the flexible drill pipe groove 8 faces the side wall of the oil pipe 3.

[0036] If Figure 2 As shown in FIG. 1 , a flexible drill pipe groove 8 is provided on the upper surface of the whipstock 2, i.e., the inclined surface. The cross section of the flexible drill pipe groove 8 is also triangular, and the bottom edge extends all the way to the inclined surface of the whipstock 2 and intersects with the inclined surface, so that when the flexible drill pipe 4 is bent, the horizontal part can be along the bottom of the flexible drill pipe groove 8 toward the side wall of the oil pipe 3. ​​

[0037] A method for reconstructing a production channel of a gas well, comprising the following steps:

[0038] Lower a bridge plug 5 into the tubing 3 to the position where the production channel needs to be drilled and fixed the bridge plug 5 inside the tubing 3; lower a whipstock 2 above the bridge plug 5;

[0039] Lower a coiled tubing 3, a flexible drill pipe 4, a hydraulic motor 6 and a milling cone 7. The bent part of the flexible drill pipe 4 contacts the upper surface of the whipstock 2, and the milling cone 7 points to the side wall of the tubing 3;

[0040] Pressurize the coiled tubing 1 on the ground to drive the hydraulic motor 6 and the milling cone 7 to rotate and drill the side wall of the tubing 3;

[0041] Further lower the coiled tubing 1. During the lowering process, the flexible drill pipe 4 is further bent, the length of the vertical part decreases, and the length of the horizontal part increases, pushing the milling cone 7 further towards the side wall of the tubing 3, so that the milling cone 7 further grinds and drills along the previously drilled hole until the side wall of the tubing 3 is drilled through to generate a new gas flow production channel. Stop pressurizing on the ground and retrieve the coiled tubing 3, the flexible drill pipe 4, the hydraulic motor 6 and the milling cone 7.

[0042] When lowering the coiled tubing 3, the flexible drill pipe 4 is inserted into the flexible drill pipe groove 8 to fix the position of the flexible drill pipe 4.

[0043] The lowering speed of the coiled tubing 3 is less than 600 m / h.

[0044] During use, first lower the bridge plug 5 and the whipstock 2 to the position where drilling is required.

[0045] Lower the coiled tubing 3, the flexible drill pipe 4, the hydraulic motor 6 and the milling cone 7. Before lowering, bend the flexible drill pipe 4 until the bending point of the flexible drill pipe 4 contacts the inclined surface of the whipstock 2,

[0046] And the flexible drill pipe 4 is inserted into the flexible drill pipe groove 8 and lowered in place.

[0047] Then pressurize on the ground, and the hydraulic motor 6 drives the milling cone 7 to rotate to prepare for drilling,

[0048] During the lowering process, in order to avoid collision, there is still a certain distance between the hydraulic motor 6 and the milling cone 7 and the side wall of the tubing 3. Therefore, continue to lower the coiled tubing 1. The flexible drill pipe 4 is further bent by the external force, the length of the vertical part is shortened, and the length of the horizontal part is elongated. The milling cone 7 contacts the tubing 3 under the action of the elongation of the horizontal part to drill the hole. Then further lower the coiled tubing 1, so that the horizontal part of the flexible drill pipe 4 is further elongated, and the milling cone 7 can penetrate into the wall of the tubing 3 until the milling cone 7 drills through the side wall of the tubing 3 to form a new production channel.

[0049] Such as Figure 3As shown, it can be seen that as the coiled tubing 1 is lowered, the right end of the flexible drill rod 4 extends further, approaches and penetrates into the side wall of the tubing 3, and pushes the milling cone 7 to drill through the entire side wall of the tubing 3.

[0050] During this process, the partially drilled hole and the flexible drill rod groove 8 define the position of the flexible drill rod 4, preventing the flexible drill rod 4 from shaking left and right when it is bent.

[0051] After that, the ground pressure is stopped, the coiled tubing 1 is lifted up, and the flexible drill pipe 4, hydraulic motor 6 and milling cone 7 are pulled out at once, so that the gas well can be restarted for production. This solves the problem that the choke falls to the bottom of the tubing and cannot be salvaged, blocking the air flow channel, causing a serious drop in gas well production or even shutdown, and provides a new means for resuming production of shutdown wells.

Claims

1. A gas well production channel reconstruction device, characterized in that: The invention comprises a continuous oil pipe (1) and a whipstock (2) connected to the oil pipe (3); a flexible drill rod (4) is connected below the continuous oil pipe (1); the flexible drill rod (4) is bent, and the other end faces the side wall of the oil pipe (3); a hydraulic motor (6) is connected to one end of the flexible drill rod (4) facing the side wall of the oil pipe (3); a milling cone (7) is connected to the output shaft of the hydraulic motor (6); the drill head of the milling cone (7) faces the side wall of the oil pipe (3); and the flexible drill rod (4) is a hollow pipe.

2. A gas well production channel reconstruction device according to claim 1, characterized in that: It also comprises a bridge plug (5), which is connected inside the oil pipe (3), and a whipstock (2) is connected above the bridge plug (5).

3. A gas well production channel reconstruction device according to claim 1, characterized in that: The whipstock (2) is an inclined platform with an upper surface inclined downward.

4. A gas well production channel reconstruction device according to claim 3, characterized in that: The upper surface of the whipstock (2) is also provided with a downwardly recessed flexible drill rod groove (8), and the width of the flexible drill rod groove (8) matches that of the flexible drill rod (4).

5. A gas well production channel reconstruction device according to claim 4, characterized in that: The cross section of the flexible drill rod groove (8) is triangular, and the bottom edge of the flexible drill rod groove (8) faces the side wall of the oil pipe (3).

6. A method for reconstructing a gas well production channel according to any one of claims 1 to 5, characterized in that: The following steps are involved: Lowering the bridge plug (5) into the oil pipe (3) to the position where the re-production channel is to be drilled, and fixing the bridge plug (5) in the oil pipe (3); lowering the whipstock (2) to the top of the bridge plug (5); The coiled tubing (3), the flexible drill pipe (4), the hydraulic motor (6) and the milling cone (7) are lowered, the bent portion of the flexible drill pipe (4) contacts the upper surface of the whipstock (2), and the milling cone (7) points to the side wall of the tubing (3); The ground pressurizes the inside of the coiled tubing (1), driving the hydraulic motor (6) and the milling cone (7) to rotate, thereby drilling holes in the side wall of the tubing (3); The coiled tubing (1) is further lowered, and the flexible drill pipe (4) is further bent during the lowering process, the length of the vertical portion is reduced, and the length of the horizontal portion is increased, and the milling cone (7) is further pushed toward the side wall of the tubing (3), so that the milling cone (7) further grinds and drills along the previously drilled hole, and the side wall of the tubing (3) is directly drilled through, generating a new air flow production channel, and the ground pressure is stopped, and the coiled tubing (3), the flexible drill pipe (4), the hydraulic motor (6) and the milling cone (7) are pulled out.

7. A method for reconstructing a gas well production channel according to claim 6, characterized in that: When the coiled tubing (3) is lowered, the flexible drill rod (4) is inserted into the flexible drill rod groove (8) to fix the position of the flexible drill rod (4).

8. A method for reconstructing a gas well production channel according to claim 6, characterized in that: The running speed of the coiled tubing (3) is less than 600 m / h.

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