Out-casing windowing drill bit and method capable of achieving directional sand blasting perforation

Abstract

The invention discloses a casing external windowing drill bit capable of achieving directional sand blasting perforation and a method. The drill bit comprises a drill bit body, a rotary valve, a fixed valve and an eccentric balance weight. The rotary valve and the fixed valve are vertically arranged in the drill bit body, the fixed valve is fixed to the drill bit body, and the rotary valve can rotate relative to the fixed valve; the eccentric balance weight is fixed to the upper portion of the rotary valve, and the rotary valve can rotate under the action of eccentric gravity so that the eccentric balance weight can be arranged at a preset balance weight position. A nozzle is arranged on the lower portion of the drill bit body and communicated with the rotary valve, the fixed valve and the nozzle to form a flow channel. A first opening is formed in the bottom of the rotary valve; a second opening corresponding to the nozzle is formed in the bottom of the fixed valve; the first opening and the second opening can be aligned or at least partially staggered under the rotation action of the rotary valve so as to control the overflowing area of the flow channel; the drill bit can ensure that the jet flow direction is accurately aligned with a treatment well casing, the accuracy and efficiency of sand blasting perforation are improved, and then the success rate and efficiency of follow-up windowing are improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas drilling, and in particular to a casing external window drill bit capable of directional sandblasting and perforating and a method thereof. Background Art

[0002] With the long-term exploration and development of oil and gas resources, there are a large number of depleted wells and abandoned wells in some old oil fields. The wellbore of these depleted wells and abandoned wells has been in service for a long time, and the casing has been corroded and worn. In addition, due to the perforation, well repair, alternating injection and production and other operation measures, the wellbore casing, cement ring, etc. have been damaged to varying degrees, causing the wellbore to lose its sealing, which in turn leads to leakage inside and outside the casing and interlayer channeling. In addition, during the oil and gas production operation, oil, gas, water, etc. will flow to the wellhead, and the surface near the wellhead will be infiltrated and soaked for a long time, resulting in loose soil and liquefaction near the wellhead, and the wellhead may collapse and be buried. Therefore, the complex situation of leakage in old wells will pose a long-term hidden danger to the later injection and production operations of the oil field, resource potential, and the construction of gas storage for depleted oil and gas reservoirs. The safety and environmental protection of old wells is a major problem currently facing old oil fields.

[0003] Effective underground plugging is a reliable way to safely and environmentally manage old wells. However, due to long-term mining, well repair operations, production increase and transformation measures, a large number of old wells currently have casing deformation, casing misalignment, wellhead or underground collapse, fish falling and other complex conditions, resulting in the inability of operating tools and plugging materials used in the plugging process of old wells to re-enter the wellbore of the old wells to form an effective plug. Therefore, it is necessary to drill new rescue wells around the treatment wells (old wells that need to be treated), and to achieve effective connection between the rescue wells and the treatment wells underground, and to establish a communication channel using the rescue wells, and then to achieve complete plugging of the treatment wells underground. To achieve effective connection between the rescue wells and the treatment wells, it is necessary to mill and open windows in the treatment wells in the rescue wells. Summary of the invention

[0004] In order to enrich the product categories of window-opening drill bits and increase the selection space of window-opening methods outside the casing, the present invention provides a window-opening drill bit outside the casing capable of directional sandblasting and perforating and a method thereof.

[0005] In a first aspect, an embodiment of the present invention provides a casing external window drill bit capable of directional sandblasting and perforating, comprising a drill bit body, a rotary valve, a fixed valve and an eccentric counterweight; The rotary valve and the fixed valve are arranged vertically inside the drill body, the fixed valve is fixed to the drill body, and the rotary valve can rotate relative to the fixed valve; The eccentric counterweight is fixed to the upper part of the rotary valve, and the rotary valve can rotate under the action of eccentric gravity so that the eccentric counterweight is located at a preset counterweight position; A nozzle is provided at the lower part of the drill body, and the rotary valve, the fixed valve and the nozzle are connected to form a flow channel; The bottom of the rotary valve is provided with a first opening; the bottom is provided with a second opening corresponding to the nozzle; the first opening and the second opening can be aligned or at least partially staggered under the rotation of the rotary valve to control the flow area of ​​the flow channel.

[0006] In one or some optional embodiments, the casing external window drill bit capable of directional sandblasting and perforating further includes an elastic member; The elastic member is sleeved on the rotary valve and placed between the fixed valve and the eccentric weight; The elastic member is in a pre-stressed state and is suitable for supporting the rotary valve; The side wall of the rotary valve is provided with a guide key; the side wall of the fixed valve is provided with a guide groove, and the upper end is provided with a guide slope; the rotary valve can compress the elastic part downward under the action of fluid pressure so that the guide key is stuck in the guide groove, or the guide key slides along the guide slope.

[0007] In one or some optional embodiments, the angle between the radius where the guide key is located and the radius where the first opening is located is equal to the angle between the radius where the guide groove is located and the radius where the second opening is located.

[0008] In one or some optional embodiments, a counterweight installation portion distributed circumferentially along a side wall of the rotary valve is provided on the upper portion of the rotary valve; The eccentric weight can be installed at different positions of the weight installation portion to adjust the orientation of the eccentric weight relative to the first opening.

[0009] In one or some optional embodiments, the lower portion of the drill body is stepped, and a stepped groove is provided on the stepped surface; The stepped groove is disposed above the nozzle.

[0010] In one or some optional embodiments, the first opening is in the shape of a sector with the center of the bottom of the rotary valve as the vertex; The second opening is in the shape of a fan with the center of the bottom of the fixed valve as the vertex.

[0011] In one or some optional embodiments, the eccentric weight includes an inner eccentric weight and an outer eccentric weight; The inner eccentric weight is installed on the inner wall of the rotary valve; The outer eccentric counterweight is installed on the outer wall of the rotary valve.

[0012] In one or some optional embodiments, the casing external window drill bit capable of directional sandblasting and perforating further comprises a compression sleeve fixed to the drill bit body; The compression sleeve is placed between the outer eccentric weight and the fixed valve, and is suitable for compressing and fixing the fixed valve inside the drill body; The rotary valve is inserted into the compression sleeve and can rotate relative to the compression sleeve.

[0013] In one or some optional embodiments, the casing external window drill bit capable of directional sandblasting and perforating further includes a bearing; The rotary valve is inserted into the bearing and can rotate relative to the bearing; The bearing is placed between the pressing sleeve and the elastic member.

[0014] In one or some optional embodiments, the casing external window drill bit capable of directional sandblasting and perforating further comprises an elastic seat; The elastic seat is arranged between the elastic member and the bearing to support the elastic member.

[0015] In one or some optional embodiments, a first central hole is provided at the bottom of the rotary valve; A second center hole is arranged at the center of the rotary valve.

[0016] In one or some optional embodiments, the drill body includes an upper joint and a step drill bit connected up and down.

[0017] In a second aspect, an embodiment of the present invention provides a casing external window opening method for directional sandblasting perforation, using the casing external window opening drill bit capable of directional sandblasting perforation, comprising: Connect the drill bit with window outside the casing capable of directional sandblasting and perforating to the drill pipe and lower it into the rescue well; Connect the drill pipe to the mud pump; Starting the mud pump to pump mud into the rescue well and obtaining changes in pump pressure; Determine whether the pump pressure is abnormally high; If yes, turn off the mud pump, rotate the drill pipe to a preset angle, restart the mud pump, obtain the pump pressure change and determine whether the pump pressure increases abnormally; If not, connect the drill pipe to the high-pressure abrasive jet pipeline and perform sandblasting perforation on the casing of the treatment well so that the window drill bit outside the casing that can be directional sandblasting perforation can be stuck in the cut obtained after perforation; Rotate the casing window drill bit capable of directional sandblasting and perforating to open windows and expand holes in the casing of the treatment well.

[0018] In one or some optional embodiments, before connecting the casing window drill bit capable of directional sandblasting and perforating to the drill pipe and lowering it into the rescue well, the method further includes: According to the orientation of the casing of the treatment well, the orientation of the eccentric weight in the casing window drill bit capable of directional sandblasting and perforating is set so that the first opening can always be aligned with the casing of the treatment well under the action of eccentric gravity.

[0019] The beneficial effects of the above technical solution provided in the embodiments of the present invention include at least: The casing external window drill bit capable of directional sandblasting and perforating provided in an embodiment of the present invention uses an eccentric counterweight to control the orientation of the first opening, thereby realizing automatic adjustment of the direction of the first opening, so that the first opening is aligned with the treatment well casing under the action of the gravity exerted on the eccentric counterweight; the first opening and the second opening cooperate with each other to control the flow area of ​​the flow channel, thereby forming different pressure drops in the flow channel, so that it is possible to judge whether the first opening is aligned with the second opening through the pressure condition fed back in the flow channel, and then to know whether the nozzle injection direction is aligned with the treatment well casing, which helps to adjust the position of the downhole nozzle, ensure that the jet direction is accurately aligned with the treatment well casing, improve the accuracy and efficiency of sandblasting and perforating, and then improve the success rate and efficiency of subsequent window opening.

[0020] The embodiment of the present invention provides a casing external window drill bit capable of directional sandblasting and perforating. After fluid is introduced into the flow channel, the rotary valve can compress the elastic part downward under the action of the fluid pressure. By setting the position correspondence between the first opening, the guide key, the second opening, the guide groove and the guide slope, when the first opening is aligned with the second opening, the flow channel is in a smooth state, ensuring that the pressure in the flow channel is relatively stable. When the first opening is not aligned with the second opening, the flow area of ​​the flow channel is greatly reduced, which increases the pressure in the flow channel, thereby realizing the judgment and adjustment of the injection direction of the rescue downhole nozzle according to pressure feedback.

[0021] The embodiment of the present invention provides a casing external window drill bit capable of directional sandblasting perforation, wherein the stepped groove can be stuck in the jet cutting slot after the sandblasting perforation is completed, thereby preventing the casing external window drill bit capable of directional sandblasting perforation from positional displacement during the milling and window opening process, thereby improving the success rate and efficiency of the milling and window opening and hole expansion operations.

[0022] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the first cross-sectional structure of a casing external window drill bit capable of directional sandblasting and perforating provided in an embodiment of the present invention; Figure 2 A second cross-sectional structural schematic diagram of a casing external window drill bit capable of directional sandblasting and perforating provided in an embodiment of the present invention; Figure 3 Provided in the embodiments of the present invention Figure 2 AA section view; Figure 4 Provided in the embodiments of the present invention Figure 2 BB cross-sectional view; Figure 5 It is a schematic diagram of a partial three-dimensional structure of a casing external window drill bit capable of directional sandblasting and perforating provided in an embodiment of the present invention; Figure 6 A schematic diagram of a first external structure of a casing external window drill bit capable of directional sandblasting and perforating provided in an embodiment of the present invention; Figure 7 A schematic diagram of a second external structure of a casing external window drill bit capable of directional sandblasting and perforating provided in an embodiment of the present invention; Figure 8 A schematic diagram of directional sandblasting perforation operation of a casing external window drill bit capable of directional sandblasting perforation provided in an embodiment of the present invention; Fig. 9 A schematic diagram of a window opening operation of a casing external window opening drill bit capable of directional sandblasting and perforating provided in an embodiment of the present invention; Fig.10 The present invention is a schematic flow chart of a casing external window opening method capable of directional sandblasting and perforating provided in an embodiment of the present invention.

[0025] In the figure: 1 is a drill body, 101 is an upper joint, 102 is a stepped drill, 1021 is a nozzle, 1022 is a stepped groove, 2 is a rotary valve, 201 is a first opening, 202 is a guide key, 203 is a first center hole, 3 is a fixed valve, 301 is a second opening, 302 is a guide groove, 303 is a guide slope, 304 is a second center hole, 4 is an eccentric weight, 401 is an outer eccentric weight, 402 is an inner eccentric weight, 5 is a flow channel, 6 is an elastic member, 7 is a bolt, 8 is a clamping sleeve, 9 is a sleeve top screw, 10 is a bearing, 11 is an elastic seat, and 12 is a milling material covering surface; 100 is the casing of the treatment well and 200 is the rescue well. DETAILED DESCRIPTION

[0026] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0027] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "far", "near", "front", "back" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] The inventor found that in the process of connecting the newly drilled rescue well and the treatment well, it is necessary to drill a window in the treatment well in the rescue well to drill through the cement ring and casing of the treatment well. Since the outer surface of the treatment well casing is arc-shaped, there is a large strength difference between the casing and the formation rock, and it is difficult to impose effective constraints on the drill bit in the rescue well, which often causes the milling drill bit to deviate from the treatment well position and drill into the surrounding formation, causing the wellbore connection failure. Therefore, it is necessary to propose a new type of casing external window drill bit and method, so that the drill bit can drill a window along the treatment well position to ensure effective connection between the new wellbore and the treatment wellbore, thereby providing an operating channel for the treatment wellbore plugging and safe and environmental protection management.

[0030] Based on this, an embodiment of the present invention provides a casing external window drill bit and method capable of directional sandblasting and perforating, which are described in detail below through specific embodiments.

[0031] Embodiment 1 The embodiment of the present invention provides a casing external window drill bit capable of directional sandblasting and perforating, referring to Figure 1-Figure 7 As shown, it includes a drill body 1, a rotary valve 2, a fixed valve 3 and an eccentric weight 4; The rotary valve 2 and the fixed valve 3 are arranged vertically inside the drill body 1. The fixed valve 3 is fixed to the drill body 1. The rotary valve 2 can rotate relative to the fixed valve 3. The eccentric weight 4 is fixed to the upper part of the rotary valve 2, and the rotary valve 2 can rotate under the action of the eccentric gravity so that the eccentric weight 4 is placed at a preset weight position; A nozzle 1021 is provided at the lower part of the drill body 1, and the rotary valve 2, the fixed valve 3 and the nozzle 1021 are connected to form a flow channel 5; The bottom of the rotary valve 2 is provided with a first opening 201 ; the bottom is provided with a second opening 301 corresponding to the nozzle 1021 ; the first opening 201 and the second opening 301 can be aligned or at least partially staggered under the rotation of the rotary valve 2 to control the flow area of ​​the flow channel 5 .

[0032] The casing external window drill bit capable of directional sandblasting and perforating (hereinafter referred to as the window drill bit) provided in the embodiment of the present invention is mainly used for sandblasting and perforating and external windowing of the treatment well casing in the rescue well. It should be noted that the treatment well in the embodiment of the present invention refers to a vertical well that needs to be treated, and the rescue well refers to a newly drilled wellbore next to the treatment well. Since the rescue well needs to be drilled into the treatment well, the rescue well will have a certain degree of inclination relative to the treatment well, and the inclination angle is generally about 2°-3°. If the window drill bit is lowered into the rescue well, the window drill bit will also be slightly inclined relative to the vertical direction. Therefore, the eccentric counterweight 4 can drive the rotary valve 2 to rotate under the action of gravity, so that the eccentric counterweight 4 is always in the preset counterweight position (the gravity low edge position of the rotary valve, that is, the lowest point position that the eccentric counterweight 4 can reach).

[0033] In the embodiment of the present invention, refer to Figure 1-Figure 9 As shown, the rotary valve 2 and the fixed valve 3 are both hollow cylindrical, the diameter of the fixed valve 3 is larger than that of the rotary valve 2, and the rotary valve 2 can partially extend into the fixed valve 3; the bottom of the rotary valve 2 is provided with a first central hole 203, and the bottom of the fixed valve 3 is provided with a second central hole 304, so that the rotary valve 2, the fixed valve 3 and the nozzle 1021 are connected, and a flow channel 5 is formed in the center of the window drill bit. Since the fixed valve 3 is fixed to the drill bit body 1, the rotation of the rotary valve 2 can change the positional relationship between the first opening 201 and the second opening 301, so that the first opening 201 and the second opening 301 are aligned, partially staggered or completely staggered, and the flow area of ​​the flow channel 5 is changed, so that the pressure drop in the flow channel 5 changes. The second opening 301 and the nozzle 1021 are arranged correspondingly, and the two can be located on the same side of the window drill bit, so that the direction of the nozzle 1021 can be judged according to the positional relationship between the first opening 201 and the second opening 301 and the pressure in the flow channel 5. The nozzle 1021 is used to spray high-pressure jet abrasives to perform sandblasting and perforating on the casing 100 of the treatment well.

[0034] In the embodiment of the present invention, a counterweight installation part (not shown in the figure) distributed along the circumference of the side wall of the rotary valve 2 is provided on the upper part of the rotary valve 2, and the eccentric counterweight 4 can be installed on the counterweight installation part at a certain angle. By installing the eccentric counterweight 4 on the counterweight installation part at different angles, the position of the eccentric counterweight 4 relative to the first opening 201 can be adjusted, so that after the window drill bit is lowered into the rescue well 200, the first opening 201 is always aligned with a fixed direction under the action of the gravity of the eccentric counterweight 4, that is, the first opening 201 can be always aligned with the treatment well casing 100 by reasonably setting the installation position of the eccentric counterweight 4.

[0035] In a specific embodiment, referring to Figure 1-Figure 5 As shown, the window drill bit also includes an elastic member 6 disposed between the eccentric weight 4 and the fixed valve 3, and the elastic member 6 is sleeved on the rotary valve 2 and is in a pre-stressed state under the pressure of the eccentric weight 4. The side wall of the rotary valve 2 is provided with a guide key 202; the side wall of the fixed valve 3 is provided with a guide groove 302, and the upper end is provided with a guide slope 303; due to the supporting effect of the elastic member 6, the guide key 202 and the guide groove 302 and the guide slope 303 are separated when the rotary valve 2 is not under pressure. The rotary valve 2 can compress the elastic member 6 downward under the action of fluid pressure, so that the guide key 202 is stuck in the guide groove 302, or the guide key 202 slides along the guide slope 303. In this embodiment, the types of the elastic member 6 include but are not limited to springs. For details, please refer to the detailed information in the prior art, which will not be repeated here.

[0036] In the embodiment of the present invention, refer to Figure 1-Figure 9As shown, the angle between the radius of the guide key 202 and the radius of the first opening 201 is equal to the angle between the radius of the guide groove 302 and the radius of the second opening 301, the lowest point of the guide slope 303 is 180° away from the wire groove (with the center of the fixed valve 3 as the common point), when the first opening 201 is aligned with the second opening 301, the guide key 202 is also aligned with the guide groove 302; when the first opening 201 is staggered with the second opening 301, the guide key 202 is also staggered with the guide groove 302. When the first opening 201 can always be aligned with the treatment well casing 100 in the rescue well 200, if the second opening 301 is not aligned with the first opening 201 (indicating that the nozzle 1021 and the second opening 301 are not aligned with the treatment well casing 100), at this time, the rotary valve 2 compresses the elastic member 6 downward under the pressure of the fluid (such as mud), and the guide key 202 cannot enter the guide groove 302, but after abutting the guide slope 303, it slides along the guide slope 303 to the lowest point of the guide slope 303, so that the first opening 201 and the second opening 301 are completely offset, the flow area of ​​the flow channel 5 is reduced to a minimum, and the pressure in the flow channel 5 increases. Since the first opening 201 can always be aligned with the treatment well casing 100 in the rescue well 200, if the second opening 301 is aligned with the first opening 201 (indicating that the nozzle 1021 and the second opening 301 are aligned with the treatment well casing 100), at this time, the rotary valve 2 compresses the elastic part 6 downward under the fluid pressure, and the guide key 202 enters the guide groove 302, and the pressure in the flow channel 5 will not increase significantly.

[0037] The window drill bit provided in the embodiment of the present invention uses an eccentric weight 4 to control the orientation of the first opening 201, thereby controlling the flow area of ​​the flow channel 5, forming different pressure drops in the flow channel 5, so that it can be known at the wellhead based on the pressure feedback whether the injection direction of the nozzle 1021 is aligned with the treatment well casing 100. Specifically, when the fluid input pressure at the wellhead increases abnormally, it means that the second opening 301 is not aligned with the first opening 201, and the nozzle 1021 is not aligned with the treatment well casing 100; when the fluid input pressure at the wellhead does not increase abnormally, it means that the second opening 301 is aligned with the first opening 201, and the nozzle 1021 is aligned with the treatment well casing 100, and the sandblasting perforation operation can be started. Therefore, the process of implementing directional sandblasting perforation with a window drill bit can include: The installation position of the eccentric weight 4 is set at the wellhead according to the direction of the treatment well relative to the rescue well 200, so that after the window drill bit is lowered into the rescue well 200, the direction of the first opening 201 is always aligned with the treatment well casing 100; Connect the window drill bit to the drill pipe and lower it into the treatment well; Connect the mud pump to the drill pipe, start the mud pump, and obtain the pump pressure changes; Determine whether the pump pressure is abnormally high; If yes, turn off the mud pump, rotate the drill pipe to a preset angle, restart the mud pump, and observe and judge again; If not, the drill pipe is connected to a high-pressure abrasive jet pipeline to perform sandblasting and perforation on the casing 100 of the treatment well.

[0038] In a specific embodiment, referring to Figure 5 As shown, the first opening 201 is in the shape of a sector with the bottom center of the rotary valve 2 as the vertex, and the second opening 301 is in the shape of a sector with the bottom center of the fixed valve 3 as the vertex. The vertex angle of the first opening 201 can be equal to the vertex angle of the second opening 301, so that when the first opening 201 is aligned with the second opening 301, the flow area of ​​the flow channel 5 is the largest, and when the first opening 201 is completely staggered with the second opening 301, the flow area of ​​the flow channel 5 is the smallest. Obviously, the first opening 201 and the second opening 301 are not limited to the above-mentioned setting mode, as long as the flow area control of the flow channel 5 can be achieved through the cooperation of the two, no limitation is made here.

[0039] In a specific embodiment, referring to Figure 1 and Figure 2 As shown, the eccentric weight 4 includes an inner eccentric weight 402 and an outer eccentric weight 401, wherein the inner eccentric weight 402 is mounted on the inner wall of the rotary valve 2, and the outer eccentric weight 401 is mounted on the outer wall of the rotary valve 2. A bolt 7 is inserted above and below the inner eccentric weight 402 and the outer eccentric weight 401, and the inner eccentric weight 402 and the outer eccentric weight 401 are fixed to the rotary valve 2 by two bolts 7.

[0040] In a specific embodiment, referring to Figure 1-Figure 5 As shown, the window drill bit also includes a clamping sleeve 8 and a bearing 10 fixed to the inner wall of the drill body 1. The bearing 10 is arranged above the clamping sleeve 8 and abuts against the clamping sleeve 8. The clamping sleeve 8 is placed between the outer eccentric weight 401 and the fixed valve 3. The clamping sleeve 8 is fixed to the drill body 1 by the sleeve top screw 9 to prevent the clamping sleeve 8 from moving. The fixed valve 3 is clamped and fixed inside the drill body 1; the rotary valve 2 is inserted into the clamping sleeve 8, and the outer wall of the rotary valve 2 is in clearance with the inner wall of the clamping sleeve 8, so that it can rotate relative to the clamping sleeve 8. The rotary valve 2 is inserted into the bearing 10 and can rotate relative to the clamping sleeve 8 and the bearing 10; the bearing 10 is placed below the elastic member 6 and is tightly matched with the outer wall of the rotary valve 2 to limit the rotation trajectory of the rotary valve 2 and prevent the rotary valve 2 from tilting inside the drill body 1.

[0041] In a specific embodiment, referring to Figure 1 and Figure 2 As shown, the window drill bit also includes an elastic seat 11, which is arranged between the elastic member 6 and the bearing 10 to support the elastic member 6. The elastic seat 11 is sleeved on the rotary valve 2 and has a clearance fit with the rotary valve 2, so that the rotary valve 2 can rotate relative to the elastic seat 11.

[0042] In a specific embodiment, referring to Figure 1-Figure 9 As shown, the drill body 1 includes an upper joint 101 and a step drill bit 102 connected up and down. The upper joint 101 is used to connect the drill pipe and is connected to the step drill bit 102 below by threads. The step drill bit 102 is processed into a two-step shape, and a step groove 1022 is provided on the step surface between the two steps. The step groove 1022 is placed above the nozzle 1021. After the sandblasting perforation operation is completed, a jet slit will be formed on the wall of the treatment well casing 100, and the step groove 1022 can be stuck in the jet slit. The window drill bit provided in the embodiment of the present invention can perform window opening and hole expansion after directional sandblasting perforation. Compared with directly milling the casing to open the window, the window drill bit is prevented from directly contacting the outer arc surface of the treatment well casing 100, and the large deflection force generated during the window opening process is prevented from causing the window drill bit to deviate and fail to open the window.

[0043] In a specific embodiment, referring to Figure 1 , Figure 8 and Fig. 9 As shown, the surface of the step drill bit 102 is coated with a milling material, and a milling material coating surface 12 is formed on the surface of the step drill bit 102 to prevent the step drill bit 102 from being worn. After the sandblasting perforation operation is completed, the turntable can be connected to the drill pipe to drive the window drill bit to rotate, and the milling window expansion is performed from the jet cutting slot of the treatment well casing 100 until the casing outer window opening operation is completed.

[0044] The casing outer window drill bit capable of directional sandblasting and perforating provided by the embodiment of the present invention can, after being lowered into the bottom of the rescue well 200, adjust the spray direction of its nozzle 1021 to align with the treatment well casing 100, and can maximize the flow area of ​​the flow channel 5 while aligning the spray direction of the nozzle 1021 with the treatment well casing 100; by connecting the high-pressure abrasive jet pipeline, the treatment well casing 100 can be sandblasted and perforated, thereby forming a slit on the side wall of the treatment well casing 100, so that the stepped groove 1022 can enter the jet slit to grind the treatment well casing 100, thereby constraining the window drill bit, ensuring that the window drill bit continuously drills the treatment well casing 100 along the casing orientation, completing the casing outer window operation, and improving the efficiency and success rate of the casing outer window operation.

[0045] In a specific embodiment, the window drill bit may be designed to be all-metal to improve the high temperature resistance and strength of the window drill bit, thereby increasing the service life of the window drill bit.

[0046] The casing external window drill bit capable of directional sandblasting and perforating provided in the embodiment of the present invention can adjust the injection direction of the downhole nozzle 1021 through the mutual cooperation of the rotary valve 2, the eccentric counterweight 4, the elastic member 6 and the fixed valve 3. During the window opening operation, the external window drill bit is constrained by the stepped groove 1022 to prevent the external window drill bit from shifting. The overall structure is simple and clear, the operation is simple, and it is easy to promote and has broad application prospects.

[0047] Embodiment 2 Based on the same inventive concept, the embodiment of the present invention also provides a casing external window opening method capable of directional sandblasting perforation, referring to Fig.10 As shown, including: S101: Connect a casing external window drill bit capable of directional sandblasting and perforating to a drill pipe and lower the drill bit into a rescue well 200; S102: Connect the drill pipe to the mud pump; S103: Start the mud pump to pump mud into the rescue well 200 and obtain the change of pump pressure; S104: Determine whether the pump pressure is abnormally increased, if so, execute step S105, if not, execute step S106; S105: Turn off the mud pump, rotate the drill pipe to a preset angle, and repeat step S103; S106: Connect the drill pipe to the high-pressure abrasive jet pipeline, and perform sandblasting perforation on the treatment well casing 100, so that the casing outer window drill bit capable of directional sandblasting perforation is stuck in the cut obtained after perforation; S107: Rotate the casing outer window drill bit capable of directional sandblasting and perforating to open windows and expand holes in the treatment well casing 100.

[0048] In the embodiment of the present invention, before the casing external window drill bit capable of directional sandblasting and perforating (hereinafter referred to as the window drill bit) is connected to the drill pipe and lowered into the rescue well 200, the following steps are also included: Drill a new rescue well 200, and drill the rescue well 200 into the treatment well casing 100, and perform sufficient circulation and well washing on the rescue well 200 to establish a stable and clean bottom well environment; According to the orientation of the casing 100 of the treatment well, the orientation of the eccentric weight 4 in the casing window drill bit capable of directional sandblasting and perforating is set at the wellhead so that the first opening 201 can always be aligned with the casing 100 of the treatment well under the action of eccentric gravity.

[0049] In the embodiment of the present invention, the eccentric direction of the eccentric counterweight 4 is set according to the orientation of the treatment well casing 100, so that the first opening 201 can always be aligned with the treatment well casing 100 under the action of eccentric gravity, so that after the window drill bit is lowered into the bottom of the well, when the nozzle 1021 is aligned with the orientation of the treatment well casing 100, the eccentric counterweight 4 can use its own eccentric gravity to drive the rotary valve 2 to rotate until the first opening 201 is aligned with the second opening 301, thereby realizing the maximum opening of the flow channel 5 in the window drill bit.

[0050] In the embodiment of the present invention, during the start-up of the mud pump, the pump stroke needs to be gradually increased from a low pump stroke, and the rotary valve 2 slowly descends under the action of the fluid pressure by compressing the spring. At this time, the rotary valve 2 can rotate freely under the action of the eccentric counterweight 4 and always keep the first opening 201 aligned with the treatment well casing 100, ensuring that when the window drill bit rotates to the point where the nozzle 1021 sprays in the direction of the treatment well casing 100, the rotary valve 2 can descend under the action of the fluid pressure until the guide key 202 smoothly enters the guide groove 302, thereby aligning the first opening 201 with the second opening 301, and communicating with the flow channel 5 in the window drill bit. Therefore, the wellhead pump pressure is normal and there is no abnormally high pump pressure. If the spray direction of the nozzle 1021 is not aligned with the treatment well casing 100 at this time, the guide key 202 will contact the guide slope 303 during the downward process of the rotary valve 2 under the action of fluid pressure, and the rotary valve 2 will be forced to rotate under the action of the guide key 202, so that when the rotary valve 2 descends to the fixed valve 3, the first opening 201 and the second opening 301 are staggered with each other, and the flow area of ​​the flow channel 5 in the window drill bit is reduced to a minimum, and then an obvious abnormally high pump pressure will appear at the wellhead. Based on this, when an abnormally high pump pressure occurs, it can be judged that the spray direction of the nozzle 1021 is not aligned with the treatment well casing 100 at this time, and the mud pump needs to be turned off, and the drill pipe is slowly rotated at an equidistant angle at the wellhead, and then the mud pump is started to observe the pump pressure. If the pump pressure is normal, it can be considered that the spray direction of the nozzle 1021 has been aligned with the treatment well casing 100 after the drill pipe is rotated. If it is still abnormally high pump pressure, it is necessary to continue to repeatedly rotate the drill pipe at an equidistant angle, and then start the mud pump to observe the pump pressure until the wellhead pump pressure shows normal pressure.

[0051] In the embodiment of the present invention, after the nozzle 1021 is sprayed in the direction of the treatment well casing 100, the high-pressure abrasive jet pipeline can be connected to start the sandblasting perforation operation outside the abrasive jet casing. By observing the annular pressure change or the slit time, it can be determined whether the sandblasting perforation operation is completed. A reasonable judgment method can be selected according to the actual situation. For example, if the annular pressure decreases in a short time, it means that a penetrating jet slit has been formed. After the sandblasting perforation operation is completed, the drive rod is driven to rotate, driving the window drill bit to continue to open windows and expand the casing 100 of the treatment well. Due to the transverse slit formed by the abrasive jet outside the casing, the stepped groove 1022 will be stuck in the casing slit, forming a stable constraint on the window drill bit, thereby preventing the window drill bit from deviating during the rotary milling window operation, and completing the one-trip drilling operation of positioning sandblasting perforation and milling window expansion.

[0052] The casing external window opening method with directional sandblasting perforation provided in the embodiment of the present invention can realize accurate positioning of the jet direction, so as to accurately perforate the treatment well casing 100; by cooperating with the stepped groove 1022 and the slit obtained after perforating, the window opening drill bit is constrained during the milling window opening process to prevent the window opening drill bit from deviating, thereby ensuring the smooth completion of the milling window opening and hole expansion operation.

[0053] Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various changes and modifications may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. Thus, if these changes and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A casing external window drill bit capable of directional sandblasting and perforating, characterized in that: It includes a drill body, a rotary valve, a fixed valve and an eccentric weight; The rotary valve and the fixed valve are arranged vertically inside the drill body, the fixed valve is fixed to the drill body, and the rotary valve can rotate relative to the fixed valve; The eccentric counterweight is fixed to the upper part of the rotary valve, and the rotary valve can rotate under the action of eccentric gravity so that the eccentric counterweight is located at a preset counterweight position; A nozzle is provided at the lower part of the drill body, and the rotary valve, the fixed valve and the nozzle are connected to form a flow channel; A first opening is provided at the bottom of the rotary valve; a second opening corresponding to the nozzle is provided at the bottom of the fixed valve; the first opening and the second opening can be aligned or at least partially staggered under the rotation of the rotary valve to control the flow area of ​​the flow channel.

2. The casing external window drill bit capable of directional sandblasting and perforating according to claim 1, characterized in that: Also included is an elastic member; The elastic member is sleeved on the rotary valve and placed between the fixed valve and the eccentric weight; The elastic member is in a pre-stressed state and is suitable for supporting the rotary valve; The side wall of the rotary valve is provided with a guide key; the side wall of the fixed valve is provided with a guide groove, and the upper end is provided with a guide slope; the rotary valve can compress the elastic part downward under the action of fluid pressure so that the guide key is stuck in the guide groove, or the guide key slides along the guide slope.

3. The casing external window drill bit capable of directional sandblasting and perforating according to claim 2, characterized in that: The angle between the radius where the guide key is located and the radius where the first opening is located is equal to the angle between the radius where the guide groove is located and the radius where the second opening is located.

4. The casing external window drill bit capable of directional sandblasting and perforating according to claim 1, characterized in that: The upper part of the rotary valve is provided with a counterweight installation part distributed circumferentially along the side wall of the rotary valve; The eccentric weight can be installed at different positions of the weight installation portion to adjust the orientation of the eccentric weight relative to the first opening.

5. The casing external window drill bit capable of directional sandblasting and perforating according to claim 1, characterized in that: The lower part of the drill body is stepped, and a stepped groove is provided on the stepped surface; The stepped groove is disposed above the nozzle.

6. The casing external window drill bit capable of directional sandblasting and perforating according to claim 1, characterized in that: The first opening is in the shape of a sector with the center of the bottom of the rotary valve as the vertex; The second opening is in the shape of a fan with the center of the bottom of the fixed valve as the vertex.

7. The casing external window drill bit capable of directional sandblasting and perforating according to claim 2, characterized in that: The eccentric weight includes an inner eccentric weight and an outer eccentric weight; The inner eccentric weight is installed on the inner wall of the rotary valve; The outer eccentric weight is installed on the outer wall of the rotary valve.

8. The casing external window drill bit capable of directional sandblasting and perforating according to claim 7, characterized in that: Also included is a compression sleeve fixed to the drill body; The compression sleeve is placed between the outer eccentric weight and the fixed valve, and is suitable for compressing and fixing the fixed valve inside the drill body; The rotary valve is inserted into the compression sleeve and can rotate relative to the compression sleeve.

9. The casing external window drill bit capable of directional sandblasting and perforating according to claim 8, characterized in that: Also includes bearings; The rotary valve is inserted into the bearing and can rotate relative to the bearing; The bearing is placed between the pressing sleeve and the elastic member.

10. The casing external window drill bit capable of directional sandblasting and perforating according to claim 9, characterized in that: Also included is a resilient seat; The elastic seat is arranged between the elastic member and the bearing to support the elastic member.

11. The casing external window drill bit capable of directional sandblasting and perforating according to claim 1, characterized in that: The bottom of the rotary valve is provided with a first central hole; A second center hole is arranged at the center of the rotary valve.

12. The casing external window drill bit capable of directional sandblasting and perforating according to claim 1, characterized in that: The drill body comprises an upper joint and a step drill bit which are connected up and down.

13. A method for opening a window outside a casing capable of directional sandblasting perforation, using the drill bit for opening a window outside a casing capable of directional sandblasting perforation according to any one of claims 1 to 12, characterized in that: include: Connect the drill bit with window outside the casing capable of directional sandblasting and perforating to the drill pipe and lower it into the rescue well; Connect the drill pipe to the mud pump; Starting the mud pump to pump mud into the rescue well and obtaining changes in pump pressure; Determine whether the pump pressure is abnormally high; If yes, turn off the mud pump, rotate the drill pipe to a preset angle, restart the mud pump, obtain the pump pressure change and determine whether the pump pressure increases abnormally; If not, connect the drill pipe to the high-pressure abrasive jet pipeline and sandblast the casing of the treatment well so that the window drill bit outside the casing that can be directional sandblasted and perforated can be stuck in the cut obtained after perforation; Rotate the casing window drill bit capable of directional sandblasting and perforating to open windows and expand holes in the casing of the treatment well.

14. The casing external window opening method capable of directional sandblasting perforation according to claim 13, characterized in that: Before connecting the casing window drill bit capable of directional sandblasting perforation to the drill pipe and lowering it into the rescue well, the following steps are also required: According to the orientation of the casing of the treatment well, the orientation of the eccentric weight in the casing window drill bit capable of directional sandblasting and perforating is set so that the first opening can always be aligned with the casing of the treatment well under the action of eccentric gravity.

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