Casing window opening tool and window opening method

Abstract

The present invention discloses a casing window opening tool and a window opening method, comprising: a perforation structure, including a gun body and a bullet, wherein an explosive chamber and a trajectory are arranged in the gun body, and the bullet is installed in the trajectory and located in front of the explosive chamber; a hole expansion structure, which is installed at the front end of the gun body; wherein the bullet can utilize the explosive impact force of the explosive in the explosive chamber to shoot out along the trajectory and penetrate the casing to form a perforation, and the hole expansion structure can expand the perforation into a window under the guidance of the bullet. The present invention utilizes the explosive impact energy of the explosive to shoot the bullet out and penetrate the casing of the old well to form a perforation, which can realize rapid perforation positioning outside the casing, and then the hole expansion structure can expand the perforation into a window under the guidance of the bullet, thereby solving the technical problem that the hole expansion structure is affected by the arc outer surface of the casing and the difference in hardness between the casing and the formation, causing it to deviate from the casing and cause the window opening failure, and only one drilling trip is required to complete the window opening operation outside the casing of the old well, with high operation efficiency, simple operation and strong adaptability.

Description

Technical Field

[0001] The invention relates to the technical field of oil and natural gas drilling, and in particular to a casing window opening tool and a window opening method. Background Art

[0002] With the rapid growth of demand for oil and gas energy due to the rapid development of industry and the implementation of the dual-carbon strategy, the demand for natural gas consumption will further expand. In order to adapt to the energy transformation and natural gas supply and demand characteristics under the new situation, the construction of natural gas storage is an important project to ensure the strategic reserve and stable supply of natural gas. The construction of gas storage by transforming the existing depleted oil and gas reservoirs is one of the important ways to build underground natural gas storage. However, in the process of transforming the depleted oil and gas reservoirs, most of the old wells need to be cemented to ensure the airtightness of the underground gas storage. At present, in the process of plugging the old wells, due to the many years of mining and the subsequent well repair and transformation, a large number of old wells have complicated situations such as casing change, collapse, and fish falling, and the plugging tools and materials cannot be re-entered into the wellbore to complete the plugging. Therefore, it is necessary to drill a rescue well around the old well, and realize the communication between the rescue well and the original wellbore of the old well in the well, establish a re-entry channel, and then inject cement into the rescue well to plug the old wellbore to ensure the overall sealing of the underground gas storage.

[0003] Establishing a full-size wellbore connection channel is an important guarantee to ensure the plugging effect of the old wellbore and the safety of the gas storage. In the process of connecting the rescue well with the old wellbore, the drill bit enters the formation from the wellbore of the rescue well, and then hits the casing of the old wellbore. At this time, the casing of the old wellbore needs to be perforated or the casing is opened outside the casing to complete the wellbore communication. Among them, the perforation operation has low wellbore connection efficiency, small diameter of the connecting channel, strong uncertainty of the plugging operation, and the plugging effect cannot be guaranteed; while ordinary window opening tools such as milling cones are suitable for opening windows inside the casing. When opening windows outside the casing, due to the arc outer surface of the casing and the difference in hardness between the casing and the formation, it is very easy to cause the cone head to deflect, miss the old well casing and enter the formation. Therefore, it is necessary to propose a new casing outside window opening method and supporting tools to ensure that the milling drill bit is stable during the milling window opening process, so that it can continuously drill the old well casing, quickly establish a full-size communication channel between the rescue well and the old wellbore, and then achieve safe and efficient plugging of the old wellbore, and ensure the long-term safe and stable operation of the gas storage. Summary of the invention

[0004] The purpose of the present invention is to provide a casing window opening tool and a window opening method to solve the technical problem that the current window opening tool is only suitable for opening windows inside the casing. When opening windows outside the casing, due to the arc outer surface of the casing and the difference in hardness between the casing and the formation, the cone head is easily deflected, and the old well casing is missed and the formation is entered.

[0005] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0006] The present invention provides a casing window opening tool, comprising: a perforating structure, comprising a gun body and a bullet, wherein the gun body is provided with an explosive chamber and a trajectory, and the bullet is installed in the trajectory and located in front of the explosive chamber; a hole expanding structure, installed at the front end of the gun body; wherein the bullet can utilize the explosive impact force of the explosive in the explosive chamber to be ejected along the trajectory and penetrate the casing to form a perforation, and the hole expanding structure can expand the perforation into a window under the guidance of the bullet.

[0007] In an embodiment of the present invention, the warhead is fixed in the trajectory by a fastener, and the fastener can be broken under the action of the explosion impact force.

[0008] In an embodiment of the present invention, a first positioning structure is provided on the bullet, and a second positioning structure is provided in the trajectory. The bullet is ejected along the trajectory until the first positioning structure abuts against the second positioning structure to limit the bullet from being ejected further.

[0009] In an embodiment of the present invention, the hole enlarging structure comprises a milling drill bit, and the milling drill bit mills and enlarges the perforation into the window by rotation.

[0010] In an embodiment of the present invention, the milling drill bit is provided with a sliding hole, the sliding hole is communicated with the ballistic trajectory, and a smooth bore is provided in the sliding hole.

[0011] In an embodiment of the present invention, the gun body is connected to the drill pipe through a joint, and an excitation structure is provided behind the explosive bin, and the excitation structure can use the pressure of the drilling fluid in the drill pipe to detonate the explosive bin.

[0012] In an embodiment of the present invention, the excitation structure includes a voltage-controlled exciter and an excitation seat, wherein the voltage-controlled exciter is installed in the joint, the excitation seat is installed on the gun body, a detonator is provided in the excitation seat, and the detonator extends into the explosives bin; wherein the voltage-controlled exciter can impact the excitation seat under the pressure of the drilling fluid to cause the detonator to detonate the explosives bin.

[0013] In an embodiment of the present invention, the voltage-controlled exciter is fixed in the joint by a positioning member, and the positioning member can be broken when the pressure of the drilling fluid reaches a set pressure so that the voltage-controlled exciter can move toward the excitation seat.

[0014] In an embodiment of the present invention, a sealing structure is provided between the voltage-controlled exciter and the connector.

[0015] In an embodiment of the present invention, a plurality of drilling fluid circulation holes are provided on the joint, and the plurality of drilling fluid circulation holes are connected to the annulus between the drill pipe and the wellbore; the pressure-controlled exciter has a flow channel, and the inner cavity of the drill pipe is connected to the plurality of drilling fluid circulation holes through the flow channel.

[0016] In an embodiment of the present invention, the voltage-controlled exciter is provided with a ball groove, and the flow channel is connected with the inner cavity of the drill rod through the ball groove, wherein the ball groove can cooperate with the sphere and separate the flow channel from the inner cavity of the drill rod through the sphere, and the drilling fluid in the drill rod pushes the voltage-controlled exciter toward the excitation seat by pressing down the sphere.

[0017] In an embodiment of the present invention, the drilling fluid circulation hole is arranged obliquely, and one end of the drilling fluid circulation hole connected to the annulus is arranged closer to the wellhead than one end of the drilling fluid circulation hole connected to the flow channel.

[0018] The present invention provides a window opening method, comprising the following steps: lowering a casing window opening tool into a rescue well, and making a hole expansion structure touch the casing of an old well; detonating explosives in an explosive magazine, and utilizing the force of the explosion impact to eject a bullet along a trajectory and penetrate the casing of the old well, so that a perforation is formed on the casing of the old well; and the hole expansion structure, under the guidance of the bullet, expands the perforation to form a window connecting the rescue well and the old well.

[0019] In an embodiment of the present invention, lowering the casing window opening tool into the rescue well and making the hole expansion structure touch the casing of the old well includes the following steps: completing the drilling operation of the rescue well; drilling from the bottom of the rescue well to the old well using a guide tool until the casing of the old well is touched; lowering the completion casing into the rescue well and completing the well; lowering the whipstock into the completion casing and opening a window on the completion casing to form a completion casing window; lowering the casing window opening tool into the rescue well, and making the hole expansion structure pass through the completion casing window to touch the casing of the old well.

[0020] In an embodiment of the present invention, lowering the casing window opening tool into the rescue well and making the hole expansion structure touch the casing of the old well includes the following steps: completing the drilling operation of the rescue well and performing open hole completion; using a guide tool to drill from the bottom of the rescue well to the old well until the casing of the old well is touched; lowering the casing window opening tool into the rescue well and moving it along the open hole of the rescue well to the casing of the old well.

[0021] In an embodiment of the present invention, before the casing window opening tool is lowered into the rescue well, the rescue well is circulated and flushed; after the reaming structure touches the casing of the old well and before the casing of the old well is windowed, the rescue well is further circulated and flushed.

[0022] The characteristics and advantages of the present invention are:

[0023] The casing window opening tool and the window opening method of the present invention utilize the explosive impact energy of the explosive in the explosive bin to eject the bullet and penetrate the casing of the old well to form a perforation, so that rapid perforation positioning outside the casing can be realized, and then the hole expansion structure can expand the perforation into a window under the guidance of the bullet, thereby solving the technical problem that the hole expansion structure is affected by the arc outer surface of the casing and the difference in hardness between the casing and the formation, causing it to deviate from the casing and cause the window opening failure, and ensures the stability of the hole expansion and window opening of the hole expansion structure, so as to quickly establish a communication channel between the rescue well and the old well, and then realize safe and efficient blocking of the old well, ensuring the long-term safe and stable operation of the gas storage, and only one drilling trip is required to complete the window opening operation outside the casing of the old well, so that the rescue well and the old well can be communicated, with high operation efficiency, simple operation and strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a front cross-sectional view of the window opening tool in the present invention before being activated.

[0026] Figure 2 It is a side sectional view of the window opening tool in the present invention before being activated.

[0027] Figure 3 It is a side sectional view of the window opening tool after being stimulated in the present invention.

[0028] Figure 4 It is a cross-sectional view of the hole expansion structure in the present invention.

[0029] Figure 5 This is a usage status diagram of a window opening tool in one embodiment of the present invention.

[0030] Figure 6 This is a usage status diagram of a window opening tool in another embodiment of the present invention.

[0031] In the figure:

[0032] 100, perforation structure; 200, expansion structure; 300, excitation structure;

[0033] 1. Connector; 2. Voltage-controlled activator; 3. Activator seat; 4. Gun body; 5. Sealing end cap; 6. Bullet; 7. Milling drill bit; 8. Drilling fluid circulation hole; 9. Positioning groove; 10. Fastener; 11. Ball groove; 12. Flow channel; 13. Positioning piece; 14. Detonator; 15. Explosive magazine; 16. Smoothbore; 17. Old well; 18. Casing of old well; 19. Rescue well; 20. Drill pipe; 21. Completion casing; 22. Whipstock; 23. Completion open hole; 25. Sealing structure; 26. Explosion-bearing groove; 27. Ballistics; 28. Sliding hole; 29. ​​First positioning structure; 30. Second positioning structure; 31. Ball; 32. Perforation. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0035] Implementation Method 1

[0036] like Figure 1 , Figure 2 as well as Figure 3 As shown, the present invention provides a casing window opening tool, comprising: a perforating structure 100, comprising a gun body 4 and a bullet 6, wherein the gun body 4 is provided with an explosive chamber 15 and a ballistic 27, and the bullet 6 is installed in the ballistic 27 and is located in front of the explosive chamber 15; a hole expansion structure 200, which is installed at the front end of the gun body 4; wherein, in combination with Figure 5 and Figure 6 As shown, the bullet 6 can utilize the explosive impact force of the explosive in the explosive chamber 15 to be ejected along the trajectory 27 and penetrate the casing 18 to form a perforation 32 , and the expansion structure 200 can expand the perforation 32 into a window under the guidance of the bullet 6 .

[0037] It should be noted that the present invention defines the ejection direction of the bullet 6 as the front-to-back direction, that is, the drilling direction of the window opening tool, that is, Figure 1 The present invention is particularly suitable for opening a window in the casing 18 from outside the casing 18. After the casing window opening tool is lowered from the rescue well 19, the casing 18 of the old well 17 is opened from outside the casing 18 of the old well 17, thereby forming a window connecting the rescue well 19 and the old well 17. Of course, the present invention can also be used for opening a window in the casing or opening a window in other situations.

[0038] The casing window opening tool of the present invention utilizes the explosive impact energy of the explosive in the explosive bin 15 to eject the bullet 6 and penetrate the casing 18 of the old well 17 to form a perforation 32, so as to realize rapid perforation positioning outside the casing 18, and then the hole expansion structure 200 can expand the perforation 32 into a window under the guidance of the bullet 6, thereby solving the technical problem that the hole expansion structure 200 is affected by the arc outer surface of the casing 18 and the difference in hardness between the casing 18 and the formation, causing it to deviate from the casing 18 and cause the window opening failure, and ensures the stability of the hole expansion and window opening of the hole expansion structure 200, so as to quickly establish a communication channel between the rescue well 19 and the old well 17, and then realize safe and efficient blocking of the old well 17, ensuring the long-term safe and stable operation of the gas storage, and only one drilling trip is required to complete the window opening operation outside the casing 18 of the old well 17, so that the rescue well 19 can communicate with the old well 17, with high operation efficiency, simple operation and strong adaptability.

[0039] Specifically, the front end of the bullet 6 passes through the expansion structure 200 and shoots out a distance to penetrate the casing 18 of the old well 17, while the rear end of the bullet 6 is still in the trajectory 27, so that the expansion structure 200 can move along the bullet 6 to expand the hole, thereby avoiding deviation from the casing 18 of the old well 17. The front end of the bullet 6 is generally sharp, so that it has a better ability to penetrate the casing. The rear end of the bullet 6 is provided with an explosion-bearing groove 26, which is generally spherical, so that the bullet 6 can withstand the impact force of the explosion and be ejected under the impetus of the explosion impact force. The expansion structure 200 is provided with a sliding hole 28, and the sliding hole 28 is connected to the trajectory 27. Combined with Figure 1 and Figure 4 As shown, before the bullet 6 is fired, the part of the bullet 6 near its front end extends into the slide hole 28 and slides with the slide hole 28, and the other end of the bullet 6 slides with the ballistic 27. The slide hole 28 is provided with a smooth bore 16, so that the expansion structure 200 forms a barrel for guiding the bullet 6 to be fired, and the bullet 6 rotates when fired, so as to have better penetration ability, and can maintain a predetermined direction after firing, ensuring that the bullet 6 can accurately hit the window position of the casing 18 of the old well 17.

[0040] like Figure 2 , Figure 3 as well as Figure 5 and Figure 6As shown, in an embodiment of the present invention, the hole expansion structure 200 includes a milling drill bit 7. The window opening tool is connected to the drill rod 20, and the window opening tool is lowered into the rescue well 19 through the drill rod 20. After perforating the hole 32, the window opening tool is driven to rotate by the drill rod 20, so that the milling drill bit 7 rotates to mill and expand the perforation 32 into a window. Specifically, the milling drill bit 7 is connected to the front end of the gun body 4 by a thread, and the surface of the milling drill bit 7 is coated with a milling material coating. The sliding hole 28 is located at the center of the milling drill bit 7, and the front end of the sliding hole 28 is provided with a sealing end cover 5, so that the bullet 6 is sealed inside the gun body 4 before being ejected. When the bullet 6 is ejected, it first breaks through the sealing end cover 5, and then shoots through the casing 18 of the old well 17.

[0041] like Figure 2 and Figure 3 As shown, in the embodiment of the present invention, the bullet 6 is fixed in the trajectory 27 by a fastener 10, and the fastener 10 can break under the action of the explosive impact force, thereby causing the bullet 6 to be ejected. By fixing the bullet 6 in the trajectory 27, it is prevented that the bullet 6 slides in advance and affects its firing distance. In the embodiment of the present invention, the fastener 10 is a screw, and the gun body 4 and the bullet 6 are provided with matching mounting holes for penetrating the fastener 10. The fixing method before the bullet is ejected is not specifically limited, and it can also be fixed in the trajectory by other methods, such as a snap-on structure, a limit stopper or other structures; it can also be kept fixed only by the friction between the gun body.

[0042] like Figure 2 and Figure 3 As shown, in the embodiment of the present invention, a first positioning structure 29 is provided on the bullet 6, and a second positioning structure 30 is provided in the trajectory 27. The bullet 6 is ejected along the trajectory 27 until the first positioning structure 29 abuts against the second positioning structure 30 to limit the bullet 6 from continuing to eject. The first positioning structure 29 and the second positioning structure 30 limit the ejection distance of the bullet 6 to prevent the bullet 6 from being ejected completely due to the ejection distance being too long, resulting in the inability to use the bullet 6 to guide the hole expansion structure 200 to expand the hole. Specifically, the first positioning structure 29 is an outer step surface provided on the outer wall surface of the bullet 6, and the second positioning structure 30 is an inner step surface provided on the inner wall surface of the trajectory 27 to match the outer step surface.

[0043] like Figure 1 , Figure 2 , Figure 3 as well as Figure 5 and Figure 6As shown, in the embodiment of the present invention, the gun body 4 is connected to the drill pipe 20 through the joint 1, and an excitation structure 300 is provided behind the explosive chamber 15. The excitation structure 300 can use the pressure of the drilling fluid in the drill pipe 20 to detonate the explosive chamber 15, which is simple and safe to operate. Specifically, the gun body 4 is generally a hollow structure, and the part of the cavity located between the excitation structure 300 and the explosion-bearing groove 26 forms the explosive chamber 15 for filling the explosive, and the other part of the cavity forms the ballistic 27 that slides with the warhead 6. Optionally, the explosive chamber is detonated by other feasible detonating devices in the prior art.

[0044] like Figure 2 and Figure 3 As shown, the excitation structure 300 includes a voltage-controlled exciter 2 and an excitation seat 3. The voltage-controlled exciter 2 is installed in the joint 1, and the excitation seat 3 is installed on the gun body 4. A detonator 14 is arranged in the excitation seat 3, and the detonator 14 extends into the explosive chamber 15. The voltage-controlled exciter 2 can impact the excitation seat 3 under the pressure of the drilling fluid to make the detonator 14 detonate the explosive chamber 15. Specifically, the voltage-controlled exciter 2 can also be called a voltage-controlled detonator, and the front end of the voltage-controlled exciter 2 is provided with an excitation striker for impacting the excitation seat 3. The excitation seat 3 is installed at the rear end of the gun body 4.

[0045] like Figure 2 and Figure 3 As shown, the voltage-controlled exciter 2 is fixed in the joint 1 by a positioning member 13. The positioning member 13 can break when the pressure of the drilling fluid reaches the set pressure, so that the voltage-controlled exciter 2 can move toward the excitation seat 3. The voltage-controlled exciter 2 is fixed by the positioning member 13 to prevent the voltage-controlled exciter 2 from hitting the excitation seat 3 in advance. In an embodiment of the present invention, the positioning member 13 is a positioning pin, and a positioning hole for passing the positioning pin is provided on the joint 1. A positioning groove 9 is provided on the outer wall surface of the voltage-controlled exciter 2, and one end of the positioning member 13 is inserted into the positioning groove 9. The voltage-controlled exciter 2 can also be fixed in the joint 1 by other means, such as a snap-on structure, a limit stop block or other structures. The voltage-controlled exciter 2 can also be kept fixed only by the friction between it and the joint 1.

[0046] like Figure 1 As shown, a sealing structure 25 is provided between the voltage-controlled exciter 2 and the connector 1. By providing the sealing structure 25, the sealing between the voltage-controlled exciter 2 and the connector 1 is ensured. Specifically, the sealing structure 25 includes a plurality of sealing members and a plurality of sealing grooves, the plurality of sealing grooves are arranged on the outer wall surface of the voltage-controlled exciter 2, and the plurality of sealing members are installed in the plurality of sealing grooves.

[0047] like Figure 2As shown, in the embodiment of the present invention, a plurality of drilling fluid circulation holes 8 are provided on the joint 1, and the plurality of drilling fluid circulation holes 8 are connected to the annulus between the drill pipe 20 and the wellbore; the pressure-controlled exciter 2 has a flow channel 12, and the inner cavity of the drill pipe 20 is connected to the plurality of drilling fluid circulation holes 8 through the flow channel 12. By providing the drilling fluid circulation holes 8 and the flow channel 12, a drilling fluid circulation channel between the drill pipe 20 and the annulus can be established before the window opening operation, so that the drilling fluid is circulated to wash the well, and the sand, rock debris and other bottom debris in the rescue well 19 are discharged from the wellhead, so that the expansion structure 200 can be in close contact with the casing 18 of the old well 17. Specifically, the drilling fluid circulation holes 8 are arranged obliquely, and one end of the drilling fluid circulation holes 8 connected to the annulus is arranged closer to the wellhead relative to the end of the drilling fluid circulation holes 8 connected to the flow channel 12, so that the drilling fluid can better discharge the sand, rock debris and other bottom debris from the wellhead.

[0048] Combination Figure 2 and Figure 3 As shown, after the circulation and well washing, in order to increase the pressure of the drilling fluid in the drill pipe 20 to a level that can push the pressure-controlled exciter 2 to move, the pressure-controlled exciter 2 is provided with a ball groove 11, and the flow channel 12 is connected to the inner cavity of the drill pipe 20 through the ball groove 11, wherein the ball groove 11 can cooperate with the ball 31 and separate the flow channel 12 from the inner cavity of the drill pipe 20 through the ball 31, so that the drilling fluid in the drill pipe 20 will not flow into the flow channel 12 and press down the ball 31, thereby pushing the pressure-controlled exciter 2 to move toward the excitation seat 3. The ball 31 pushes the pressure-controlled exciter 2 forward for a distance and then completes the excitation, so that the drilling fluid circulation hole 8 is staggered with the pressure-controlled exciter 2, and the inner cavity of the drill pipe 20 is reconnected with the annulus through the drilling fluid circulation hole 8 to form a drilling fluid circulation channel, so that the drilling fluid in the drill pipe 20 flows into the annulus from multiple drilling fluid circulation holes 8 and is discharged from the wellhead carrying the sediment, rock debris, milling casing debris, etc. in the rescue well 19.

[0049] Combination Figure 5 As shown in the first embodiment of the present invention, the rescue well 19 is completed by casing, and the working process of the casing window opening tool is as follows: under the action of the whipstock 22, the window opening operation of the completion casing 21 of the rescue well 19 is first completed, and after the casing 18 of the old well 17 is drilled, a full well washing cycle is performed, and then the drilling tool assembly is replaced, and the window opening tool is connected to the window opening tool.

[0050] Connect to the bottom of the drill pipe 20 and lower it into the bottom of the rescue well 19. Use downhole measuring instruments to re-measure the lowering position of the window-opening tool 5 to ensure that the hole-expanding structure 200 of the window-opening tool can accurately touch the casing 18 of the old well 17. Then, after the mud pump of the rescue well 19 is turned on to fully circulate the drilling fluid, the ball 31 is put into the drill pipe 20 and the pump pressure is gradually increased until the thrust generated by the pressure of the drilling fluid in the drill pipe 20 acting on the ball 31 and the pressure-controlled exciter 2 reaches the shear strength of the positioning member 13, the positioning member 13 is sheared, and the pressure-controlled exciter 2 and the ball 31 are under the pressure of the drilling fluid in the drill pipe 20.

[0051] It will quickly descend under the action of the pressure-controlled exciter 2. After the pressure-controlled exciter 2 descends to the bottom of the joint 4, the drilling fluid circulation hole 8 will be opened again by 0 to re-establish the drilling fluid circulation channel between the drill pipe 20 and the annulus. When the excitation pin at the bottom of the voltage-controlled exciter 2 hits the excitation seat 3, the detonator 14 in the excitation seat 3 will trigger the explosion of the explosive chamber 15 in the gun body 4, thereby breaking the fastener 10, and the bullet 6 will be ejected under the action of the explosion impact force. The bullet 6 will first break through the sealing end cover 5 and then penetrate the casing 18. Since the milling drill bit 7 of the window opening tool is pre-drilled and pressed against the outer surface of the casing 18 of the old well 17, the tip of the bullet 6 can pierce the casing 18 under the action of the explosion impact and complete the perforation 32 of the casing 18. 5 When the bullet 6 is ejected until its outer step surface abuts against the inner step surface of the gun body 4, the ejection distance of the bullet 6 is limited,

[0052] It can serve as a positioning structure for the milling drill bit 7 while completing the perforation 32 of the casing 18 of the old well 17, guiding the milling drill bit 7 to further mill and expand the perforation 32 on the casing 18 of the old well 17, limiting the deviation of the milling drill bit 7, thereby accurately and quickly completing the window opening operation outside the casing 18 of the old wellbore 17.

[0053] Combination Figure 6 As shown, in the second embodiment of the present invention, the difference is that the rescue well 19 is an open hole completion, so that the casing 18 of the old well 17 can be directly drilled. Therefore, there is no need to perform window opening operations in the completion casing 21 of the rescue well 19 as in the above-mentioned first embodiment. The casing 18 of the old well 17 can be directly opened using a casing window opening tool, and the specific working process of the casing window opening tool is the same as that of the above-mentioned first embodiment, which will not be repeated here.

[0054] Implementation Method 2

[0055] 5. Figure 1 , Figure 5 as well as Figure 6As shown, the present invention provides a window opening method, which is implemented using the casing window opening tool in embodiment 1, and includes the following steps: lowering the casing window opening tool into the rescue well 19, and making the hole expansion structure 200 touch the casing 18 of the old well 17; detonating the explosive magazine 15, and using the force of the explosion impact to shoot the warhead 6 along the trajectory 27 and penetrate the casing 18 of the old well 17, so that a through hole 32 is formed on the casing of the old well 17; under the guidance of the warhead 6, the hole expansion structure 200 expands the through hole 32 to form a window connecting the rescue well 19 and the old well 17.

[0056] Combination Figure 5 As shown, in the first embodiment of the present invention, the casing window opening tool is lowered into the rescue well 19, and the reaming structure 200 is made to touch the casing 18 of the old well 17, including the following steps: completing the drilling operation of the rescue well 19; using the guide tool to drill from the bottom of the rescue well 19 to the old well 17 until the casing 18 of the old well 17 is drilled; the completion casing 21 is lowered into the rescue well 19 and the well is completed; the deflector 22 is lowered into the completion casing 21 and a window is opened on the completion casing 21 to form a window of the completion casing 21; the casing window opening tool is lowered into the rescue well 19, and the reaming structure 200 passes through the window of the completion casing 21 to touch the casing 18 of the old well 17.

[0057] Combination Figure 6 As shown, in the second embodiment of the present invention, the casing window opening tool is lowered into the rescue well 19, and the hole expansion structure 200 is made to touch the casing 18 of the old well 17, including the following steps: completing the drilling operation of the rescue well 19 and performing open hole completion; using the guide tool to drill from the bottom of the rescue well 19 to the old well 17 until the casing 18 of the old well 17 is drilled; the casing window opening tool is lowered into the rescue well 19, and moved along the completed open hole 23 of the rescue well 19 to the casing 18 of the old well 17.

[0058] Before the casing window opening tool is lowered into the rescue well 19, the rescue well 19 is circulated and flushed. After the reaming structure 200 touches the casing 18 of the old well 17 and before the casing 18 of the old well 17 is opened, the rescue well 19 is further circulated and flushed.

[0059] Combination Figure 2 and Figure 3As shown, specifically, after circulating well washing, the drill is pulled out to replace the drilling tool assembly, the drill pipe 20 is connected to the casing window opening tool, the casing window opening tool is lowered to the bottom of the rescue well 19 through the drill pipe 20 and touches the casing 18 of the old well 17, and the ball 31 is not dropped first, so that the inner cavity of the drill pipe 20 is connected with the annulus through the flow channel 12 and multiple drilling fluid circulation holes 8 in sequence to form a drilling fluid circulation channel, the drilling fluid is pumped into the drill pipe 20 for further circulating well washing, and then the ball 31 is dropped into the drill pipe 20, and the flow channel 12 is separated from the inner cavity of the drill pipe 20 by the ball 31, and the drilling fluid The circulation is interrupted and gradually pressurized to the set pump pressure, so that the pressure of the drilling fluid in the drill pipe 20 gradually increases to be able to push the ball 31 and the pressure-controlled exciter 2 forward, and then hit the excitation seat 3, so that the detonator 14 in the excitation seat 3 detonates the explosive chamber 15, and the force of the explosion impact pushes the warhead 6 to break the fastener 10, so that the warhead 6 is ejected forward and penetrates the casing 18 of the old well 17 to form a perforation 32, and then the drill disc is opened, and the drill pipe 20 is driven to rotate through the drill disc, and the drill pipe 20 drives the milling drill bit 7 to rotate and, under the guidance of the warhead 6, the perforation 32 is milled and expanded into a window.

[0060] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A casing window opening tool, characterized in that: include: The perforation structure comprises a gun body and a bullet, wherein the gun body is provided with an explosive chamber and a ballistic trajectory, and the bullet is installed in the ballistic trajectory and is located in front of the explosive chamber; A hole expansion structure is installed at the front end of the gun body, the hole expansion structure is provided with a sliding hole, the sliding hole is connected to the ballistic trajectory, and the bullet can extend into the sliding hole; Wherein, the warhead can utilize the explosive impact force of the explosive in the explosive chamber to shoot out along the trajectory and penetrate the casing to form a perforation, and the hole expansion structure can expand the perforation into a window under the guidance of the warhead; The bullet is provided with a first positioning structure, and the trajectory is provided with a second positioning structure. The bullet is ejected along the trajectory until the first positioning structure abuts against the second positioning structure to limit the bullet from being ejected further. The gun body is connected to the drill pipe through a joint, and an excitation structure is arranged behind the explosive bin, and the excitation structure can detonate the explosive bin by utilizing the pressure of the drilling fluid in the drill pipe.

2. The casing window opening tool according to claim 1, characterized in that: The warhead is fixed in the trajectory by a fastener, and the fastener can be broken under the action of the explosion impact force.

3. The casing window opening tool according to claim 1, characterized in that: The hole enlarging structure comprises a milling drill bit, and the milling drill bit mills and enlarges the perforation into the window by rotating.

4. The casing window opening tool according to claim 3, characterized in that: The milling drill bit is provided with the sliding hole, and the sliding hole is provided with a smooth bore.

5. The casing window opening tool according to claim 1, characterized in that: The excitation structure includes a voltage-controlled exciter and an excitation seat, wherein the voltage-controlled exciter is installed in the joint, the excitation seat is installed on the gun body, a detonator is arranged in the excitation seat, and the detonator extends into the explosive bin; Wherein, the voltage-controlled exciter can impact the excitation seat under the pressure of the drilling fluid to cause the detonator to detonate the explosive bin.

6. The casing window opening tool according to claim 5, characterized in that: The voltage-controlled exciter is fixed in the joint by a positioning piece, and the positioning piece can be broken when the pressure of the drilling fluid reaches a set pressure, so that the voltage-controlled exciter can move toward the excitation seat.

7. The casing window opening tool according to claim 5, characterized in that: A sealing structure is provided between the voltage-controlled exciter and the connector.

8. The casing window opening tool according to claim 5, characterized in that: The joint is provided with a plurality of drilling fluid circulation holes, which are connected to the annulus between the drill pipe and the wellbore; the pressure-controlled exciter has a flow channel, and the inner cavity of the drill pipe is connected to the plurality of drilling fluid circulation holes through the flow channel.

9. The casing window opening tool according to claim 8, characterized in that: The voltage-controlled exciter is provided with a ball groove, and the flow channel is connected with the inner cavity of the drill pipe through the ball groove, wherein the ball groove can cooperate with the ball and separate the flow channel from the inner cavity of the drill pipe through the ball, and the drilling fluid in the drill pipe pushes the voltage-controlled exciter toward the excitation seat by pressing down the ball.

10. The casing window opening tool according to claim 8, characterized in that: The drilling fluid circulation hole is arranged obliquely, and one end of the drilling fluid circulation hole communicating with the annulus is arranged closer to the wellhead than one end of the drilling fluid circulation hole communicating with the flow channel.

11. A window opening method, characterized in that: Using the casing window opening tool according to any one of claims 1 to 10, the window opening method comprises the following steps: The casing window opening tool is lowered into the rescue well, and the hole expansion structure is made to touch the casing of the old well; Detonating the explosives in the explosive chamber, using the force of the explosion impact to shoot the warhead along the trajectory and penetrate the casing of the old well, so that a perforation is formed on the casing of the old well; The expansion structure, under the guidance of the bullet, expands the perforation to form a window connecting the rescue well and the old well.

12. The window opening method according to claim 11, characterized in that: The method of lowering the casing window opening tool into the rescue well and making the hole expansion structure touch the casing of the old well includes the following steps: completing the drilling operation of the rescue well; Drilling from the bottom of the rescue well toward the old well using a guide tool until the casing of the old well is hit; Running a completion casing into the rescue well and completing the well; Lowering a whipstock into the completion casing and opening a window on the completion casing to form a completion casing window; The casing window opening tool is lowered into the rescue well, and the hole expansion structure is made to pass through the completion casing window and touch the casing of the old well.

13. The window opening method according to claim 11, characterized in that: The method of lowering the casing window opening tool into the rescue well and making the hole expansion structure touch the casing of the old well includes the following steps: completing the rescue well drilling operation and performing open hole completion; Drilling from the bottom of the rescue well toward the old well using a guide tool until the casing of the old well is hit; The casing window opening tool is lowered into the rescue well and moved along the open hole of the rescue well to the casing of the old well.

14. The window opening method according to claim 11, characterized in that: Also includes: Before the casing window opening tool is lowered into the rescue well, the rescue well is circulated and flushed; After the reaming structure touches the casing of the old well and before the casing of the old well is opened, the rescue well is further circulated and flushed.

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