A support device for reverse circulation double-wall drilling.

Abstract

This invention provides a support device for drilling with reverse circulation double-walled drilling tools. The support device includes an upper connector, a body, and a lower connector connected in sequence, wherein the upper connector, body, and lower connector form a tubular integral unit with a hollow channel inside. An inner cylinder is installed inside the hollow channel, and the inner cylinder and the inner wall of the hollow channel form an annular channel. A liquid and / or gas inlet channel is provided in the inner cylinder. A support sleeve is fitted on the outside of the body, and the support sleeve is configured to provide support points for the reverse circulation double-walled drilling tool inside the well. The advantage of this invention is that it can prevent mud buildup on the support sleeve after rotating and scraping the well wall, and prevent loss of wellbore trajectory control.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas drilling, specifically to a support device for drilling with reverse circulation double-walled drill bits. Background Technology

[0002] With increasing emphasis on underground energy exploration and development, the number of deep and ultra-deep wells is gradually increasing, and surface wellbores are becoming larger and deeper. The leakage of drilling fluids causes varying degrees of environmental pollution, and the complex problems arising from well leakage delay drilling cycles, leading not only to higher overall costs but also significant environmental issues. Therefore, gas drilling technology is increasingly being applied to drilling operations in large surface wellbores. This technology can effectively improve the mechanical drilling rate in difficult-to-drill formations such as volcanic rocks, gravel layers, clastic rocks, and carbonate rocks. However, when using positive circulation gas drilling, the equipment investment cost is high, the footprint is large, gas consumption is high, and operating energy consumption is high, resulting in consistently high overall costs. Furthermore, in situations with poor wellbore stability or high formation water production, using large gas volumes can exacerbate wellbore erosion, increasing the possibility of wellbore instability and making it difficult to guarantee downhole safety. "Reverse circulation double-wall drilling technology" can effectively solve the above problems, but currently, the double-wall drilling tools used in this technology are not equipped with a support device. In related fields, the support devices are mostly integral centralizers that rotate with the drill string. During drilling using this technology, the drill string contains fluid (gas) inlet and outlet channels. Rock cuttings are circulated out through the fluid (gas) outlet channels of the drill string, and the annular fluid (gas) between the drill string and the well wall is in a static state (in the case of formation water and gas). The centralizer rotates for a long time, scraping the well wall, which... Without fluid cooling, wear is exacerbated, support is lost, and the support structure scrapes against the wellbore, forming mud bags that cause annular blockage. Furthermore, increased drill string rotation torque leads to fatigue failure. Additionally, upward or downward movement of the drill string creates resistance, increasing the risk of stuck pipe. Moreover, without a support device in the drill string assembly, the wellbore trajectory becomes uncontrollable, resulting in excessive inclination angles and azimuth drift, creating irregular wellbores that negatively impact subsequent drilling operations and well completion quality, severely hindering normal drilling operations and efficiency improvements. Therefore, it is necessary to provide a support device for reverse circulation double-wall drill strings that does not rotate with the drill string and reduces frictional resistance between the drill string and the wellbore.

[0003] Chinese utility model patent CN206668193U, entitled "Reverse Circulation Inner Cylinder Mechanism," discloses a reverse circulation inner cylinder structure. The outer surface of the inner cylinder is spaced with multiple centralizing blocks. When assembled with other components to form a reverse circulation drilling tool, it can achieve both conventional forward circulation drilling and, when encountering lost circulation formations, drilling fluid can pass through the reverse circulation device of the drilling tool, thus achieving reverse circulation drilling. However, this patent does not disclose a centralizing support structure that does not rotate with the drilling tool. Utility Model Content

[0004] The purpose of this invention is to address at least one of the aforementioned shortcomings of the existing technology. For example, one objective of this invention is to provide a support device for reverse circulation double-walled drilling that does not rotate with the drill string and can effectively prevent wellbore trajectory loss of control.

[0005] To achieve the above objectives, this utility model provides a support device for drilling with a reverse circulation double-walled drilling tool. The support device may include an upper connector, a body, and a lower connector connected in sequence. The upper connector, body, and lower connector form a tubular integral unit, and a hollow channel may be provided inside the tubular integral unit. An inner cylinder may be provided inside the hollow channel, and an annular channel may be formed between the inner cylinder and the inner wall of the hollow channel. A liquid inlet and / or gas inlet channel may be provided in the inner cylinder. A support sleeve may be fitted on the outside of the body. The support sleeve is configured to provide support points for the reverse circulation double-walled drilling tool in the well.

[0006] According to one or more exemplary embodiments of one aspect of the present invention, a suspension seat may be provided on the inner cylinder side near the upper connector, the suspension seat is located in the annular channel, and a plurality of holes are evenly arranged in the circumferential direction of the suspension seat.

[0007] According to one or more exemplary embodiments of one aspect of the present invention, the inner cylinder may be provided with a packing groove at one end near the upper connector, and a sealing packing may be provided in the packing groove.

[0008] According to one or more exemplary embodiments of one aspect of the present invention, a straightening body may be provided on the inner cylinder side near the lower connector.

[0009] According to one or more exemplary embodiments of one aspect of the present invention, the outer edge of the end face of the inner cylinder near the upper connector may be provided with an inward chamfer; the inner edge of the end face of the inner cylinder near the lower connector may be provided with an outward chamfer.

[0010] According to one or more exemplary embodiments of one aspect of the present invention, the support sleeve may be composed of a plurality of spiral strips, and a spiral guide groove may be provided between adjacent spiral strips; the surface of the spiral strip may be provided with a wear-resistant strip.

[0011] According to one or more exemplary embodiments of one aspect of the present invention, a wear-resistant strip may be provided between the support sleeve and the body.

[0012] According to one or more exemplary embodiments of one aspect of the present invention, the material of the wear-resistant belt may include tungsten carbide.

[0013] According to one or more exemplary embodiments of one aspect of the present invention, the main body may be provided with an upper limit ring and a lower limit ring limiting support sleeve, the upper limit ring and the lower limit ring being located at both ends of the support sleeve.

[0014] According to one or more exemplary embodiments of one aspect of the present invention, the upper limit ring may be provided with a fixing bolt to fix the upper limit ring to the body.

[0015] Compared with the prior art, the beneficial effects of this utility model include at least one of the following:

[0016] (1) The support device provided by this utility model further reduces the contact area between the drill bit and the well wall. It relies on the support sleeve to form support on the well wall, changing the surface contact to point contact. This avoids the drill bit above and below the support device from contacting the well wall due to centrifugal force and well trajectory during rotation. The support sleeve forms a support point in the entire drill bit assembly, thereby reducing the frictional resistance between the drill bit and the well wall and avoiding excessive torque that could cause drill bit fatigue failure.

[0017] (2) The support device provided by this utility model reduces its own wear and avoids the problem of annular blockage caused by the formation of mud bags from scraping the well wall. Attached Figure Description

[0018] The above and other objects and / or features of this utility model will become clearer from the following description taken in conjunction with the accompanying drawings, wherein:

[0019] Figure 1 A schematic diagram of a support device structure for reverse circulation double-walled drilling is shown in an exemplary embodiment of the present invention.

[0020] Figure 2 It shows Figure 1 A cross-sectional view along the AA direction;

[0021] Figure 3 It shows Figure 1 A cross-sectional view along the CC direction;

[0022] Figure 4 It shows Figure 1 Cross-sectional view along the BB direction;

[0023] Figure 5The diagram shows the usage status of a support device for reverse circulation double-walled drilling, an exemplary embodiment of the present invention.

[0024] Explanation of key figure labels:

[0025] 1-Upper connector, 2-Support sleeve, 3-Lower connector, 4-Upper limit ring, 5-Lower limit ring, 6-Male thread, 7-Fixing bolt, 8-Wear-resistant belt, 9-Female thread, 10-Inner cylinder, 11-Inlet and / or gas passage, 12-Drain and / or gas passage, 13-Sealing packing, 14-Suspension seat, 15-Centering body, 16-Well wall, 17-Drill tool, 18-Support device, 19-Drill bit. Detailed Implementation

[0026] In the following description, a support device for reverse circulation double-walled drilling according to the present invention will be explained in detail with reference to exemplary embodiments.

[0027] In the description of this application, it should be understood that the terms "center," "upper," "lower," "inner," and "outer," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In the description of this utility model, unless otherwise stated, "a plurality of" or "several" means two or more.

[0028] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] First exemplary embodiment

[0030] This exemplary embodiment provides a support device for drilling with a reverse circulation double-walled drill string.

[0031] Figure 1 A schematic diagram of a support device structure for reverse circulation double-walled drilling is shown in an exemplary embodiment of the present invention. Figure 2 It shows Figure 1 A cross-sectional view along the AA direction; Figure 3 It shows Figure 1 A cross-sectional view along the CC direction; Figure 4 It shows Figure 1 Cross-sectional view along the BB direction; Figure 5A diagram illustrating the usage state of a support device for reverse circulation double-walled drilling tools according to an exemplary embodiment of the present invention is shown below. Figures 1-5 This exemplary embodiment describes a support device for drilling with a reverse circulation double-walled drill string.

[0032] In this exemplary embodiment, as Figure 1 As shown in Figure 2, the support device mainly includes an upper connector 1, a body, and a lower connector 3 connected in sequence, wherein the upper connector 1, the body, and the lower connector 3 form a tubular integral structure, such as... Figure 2 As shown, the tubular integral body has a hollow channel inside, and an inner cylinder 10 can be installed inside the hollow channel. The inner cylinder 10 and the inner wall of the hollow channel form an annular channel, which is configured as a liquid drainage and / or gas channel 12. A liquid inlet and / or gas inlet channel 11 is provided in the inner cylinder 10; as Figure 1 As shown in Figure 2, a support sleeve 2 may be fitted onto the outer side of the main body, such as... Figure 2 As shown, the support sleeve 2 is in contact with the wear-resistant belt 8. They are not made as a whole. The support sleeve does not rotate with the main body. The support sleeve 2 and the main body are set separately.

[0033] like Figure 5 As shown, a support device 18 (referring to the support device used in this application for reverse circulation double-wall drilling) is provided between the drill string 17 and the drill bit 19. The support sleeve on the support device 18 is configured to provide a support point for the reverse circulation double-wall drilling tool within the well wall 16.

[0034] In this exemplary embodiment, as Figure 2 As shown, a suspension seat 14 may be provided on the side of the inner cylinder 10 near the upper connector 1, and the suspension seat 14 is located in the annular channel; as Figure 3 As shown, a number of semi-circular arc-shaped holes, such as four, can be evenly arranged in the circumferential direction of the suspension seat 14. The arc-shaped holes can be used to connect the inner cylinder with the upper circulating drilling tool for drainage and / or gas passage.

[0035] In this exemplary embodiment, as Figure 2 As shown, the inner cylinder 10 may be provided with a packing groove at one end near the upper connector 1, and a sealing packing 13 may be provided in the packing groove. When the inner cylinder 10 is fitted into the inner cylinder of the upper reverse circulation drill bit, a seal is formed.

[0036] In this exemplary embodiment, as Figure 2 As shown, a straightening body 15 may be provided in the circumferential direction on one side of the inner cylinder 10 near the lower connector 3. Here, for example... Figure 4 As shown, the straightening body 15 can be set as a prism, and the number of prisms can be 4. The prisms are evenly arranged in the circumferential direction on the outer side of the inner cylinder 10 near the lower connector 3 to straighten the inner cylinder 10.

[0037] In this exemplary embodiment, the outer edge of the top end face of the inner cylinder (the end of the inner cylinder near the upper connector) may be provided with an inward chamfer; the inner edge of the bottom end face of the inner cylinder (the end of the inner cylinder near the lower connector) may be provided with an outward chamfer, which facilitates the insertion of the inner cylinder into the reverse circulation drilling tools above and below the support device during construction.

[0038] In this exemplary embodiment, as Figure 1 As shown, the support sleeve 2 can be composed of several spiral strips, the spiral direction of which is the same as that shown in the figure. Figure 2 The female thread 9 of the upper connector 1 shown and as follows Figure 1 Or, as shown in Figure 2, the male thread 6 of the lower connector 3 has the same rotation direction; a spiral guide groove can be provided between adjacent spiral bands; a wear-resistant band can be provided on the surface of the spiral band to reduce wear between it and the well wall. Furthermore, such as... Figure 2 As shown, a wear-resistant strip 8 may also be provided between the support sleeve 2 and the body. The wear-resistant strip 8 between the support sleeve 2 and the body can reduce the wear generated between the support sleeve 2 and the body.

[0039] Furthermore, the length of the support sleeve can be 150–300 mm, for example, 177 mm, 192 mm, 236 mm, or 274 mm; the dimensions of the body can be matched with the outer diameter of the upper and lower drill bits for connection; the maximum outer diameter of the support sleeve can be 15 mm or more larger than the diameter of the body, and the maximum diameter of the support sleeve is 3–10 mm or more smaller than the outer diameter of its matching drill bit; the helix angle of the spiral band can be 10°–20°, for example, 13°, 15°, or 17°. Figure 1 As shown in Figure 2, the longitudinal section of the support sleeve 2 is elliptical. The elliptical design is conducive to the smooth passage of the support device through irregular wells and is less likely to cause jamming.

[0040] In this exemplary embodiment, the material of the wear-resistant belt may include tungsten carbide to enhance its wear resistance. Of course, the present invention is not limited to this, and the wear-resistant belt may also be made of other wear-resistant materials.

[0041] In this exemplary embodiment, as Figure 1 As shown in Figure 2, the main body may be provided with an upper limit ring 4 and a lower limit ring 5 to limit the support sleeve 2, with the upper limit ring 4 and lower limit ring 5 located on both sides of the support sleeve 2. The upper limit ring 4 and lower limit ring 5 can limit and position the support sleeve 2 on the main body to prevent it from loosening. In addition, the upper limit ring 4 is detachably connected to the main body, and the upper limit ring 4 may have a thread inside that connects to the upper connector 1. The direction of this thread is the same as that shown in Figure 2. Figure 2 The female thread 9 at the upper connector 1 shown in the figure and as shown in the figure Figure 1Alternatively, the male thread 6 at the lower connector 2 shown in Figure 2 is rotated in the opposite direction to prevent reverse threading during downhole use and to facilitate disassembly, making it convenient to replace the support sleeve 2 and repair the wear-resistant belt. Since the upper limit ring 4 is detachably connected to the body, the support sleeve 2 can be removed and disassembled. At the same time, considering that downhole tools should minimize threaded connections or assembly to avoid weak points at the connection, the lower limit ring 5 can be integrally set with the lower body.

[0042] In this exemplary embodiment, as Figure 1 As shown, the upper limit ring 4 may be provided with a fixing bolt 7, which can limit and fix the upper limit ring 4 to the pipeline body, and further limit the support sleeve 2.

[0043] In this exemplary embodiment, as Figure 2 As shown, the upper connector 1 may be provided with a female thread 9; as Figure 1 As shown in Figure 2, the lower connector 3 may be provided with a male thread 6.

[0044] In summary, the advantages of this utility model may include at least one of the following:

[0045] (1) The support device provided by this utility model does not follow the torque rotation and will not fail due to fatigue damage caused by the increase of the rotation torque of the drill bit.

[0046] (2) The support device provided by this utility model can prevent the support sleeve from getting mud-covered after rotating and scraping the well wall, and prevent the well trajectory from getting out of control.

[0047] (3) The support device provided by this utility model can effectively avoid the stuck drill failure caused by the collision between the drill bit and the well wall, which leads to the instability and collapse of the well wall.

[0048] Although the present invention provides a support device for reverse circulation double-wall drilling tools, as described above in conjunction with exemplary embodiments, those skilled in the art should understand that various modifications and changes can be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined by the claims.

Claims

1. A support device for use in drilling a well with an under-reaming double-wall drill, characterized in that, The support device includes an upper connector, a body, and a lower connector connected in sequence, wherein... The upper connector, the main body, and the lower connector form a tubular whole, and the tubular whole has a hollow channel inside; An inner cylinder is installed inside the hollow channel, and the inner cylinder and the inner wall of the hollow channel form an annular channel. Liquid and / or gas inlet channels are provided in the inner cylinder. A support sleeve is fitted on the outside of the main body. The support sleeve is configured to provide support points for the reverse circulation double-wall drilling tool in the well.

2. The support apparatus for reverse circulation double wall drill for drilling a well according to claim 1, wherein A suspension seat is provided on the inner cylinder side near the upper connector. The suspension seat is located in the annular channel, and several holes are evenly arranged in the circumferential direction of the suspension seat.

3. The support apparatus for reverse circulation double wall drill for drilling a well according to claim 1, wherein The inner cylinder is provided with a packing groove at one end near the upper connector, and a sealing packing is provided in the packing groove.

4. The support apparatus for reverse circulation double wall drill for drilling a well according to claim 1, wherein A straightening body is provided on the side of the inner cylinder near the lower connector.

5. The support apparatus for reverse circulation double wall drill tools for drilling a well according to claim 1, wherein, The inner cylinder has an inward chamfer on the outer edge of the end face near the upper connector; the inner cylinder has an outward chamfer on the inner edge of the end face near the lower connector.

6. The support apparatus for reverse circulation double wall drill tools for drilling a well according to claim 1, wherein, The support sleeve is composed of several spiral strips, with spiral guide grooves between adjacent spiral strips; the surface of the spiral strips is provided with wear-resistant strips.

7. The support device for reverse circulation double-walled drilling according to claim 1, characterized in that, A wear-resistant strip is provided between the support sleeve and the body.

8. The support device for reverse circulation double-walled drilling according to claim 6 or 7, characterized in that, The wear-resistant belt is made of tungsten carbide.

9. The support device for reverse circulation double-walled drilling according to claim 1, characterized in that, The main body is provided with an upper limit ring and a lower limit ring limiting support sleeve, with the upper limit ring and the lower limit ring located at both ends of the support sleeve.

10. The support device for reverse circulation double-walled drilling according to claim 9, characterized in that, The upper limit ring is equipped with fixing bolts to fix the upper limit ring to the body.

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