阅读说明：本技术 一种双壁钻柱组件、钻井设备及钻井方法 (Double-wall drill string assembly, drilling equipment and drilling method ) 是由 周松民 冼敏元 罗幼安 黄玉泉 宋林松 颜波 马德新 张方义 李春 仲莹 陈建军 于 2020-06-10 设计创作，主要内容包括：本发明实施例公开一种双壁钻柱组件、钻井设备及钻井方法,双壁钻柱组件包括一个或多个依次连接的钻柱单元和与所述一个或多个依次连接的钻柱单元配合安装的钻头胎体,所述钻柱单元包括外筒和套设于所述外筒内的内筒,所述内筒与所述钻头胎体配合形成用于注入流体的第一通道,所述外筒和内筒之间的环隙与所述钻头胎体配合形成用于输出渣体的第二通道。本发明实施例能够提高钻井效率。(The embodiment of the invention discloses a double-wall drill string component, drilling equipment and a drilling method. The embodiment of the invention can improve the drilling efficiency.)

1. A double-walled drill string assembly, characterized by: the double-walled drill string assembly comprises one or more successively connected drill string units and a bit matrix mounted in cooperation with the one or more successively connected drill string units; the drill string unit comprises an outer cylinder and an inner cylinder sleeved in the outer cylinder, the inner cylinder is matched with the drill bit matrix to form a first channel for injecting fluid, and an annular gap between the outer cylinder and the inner cylinder is matched with the drill bit matrix to form a second channel for outputting slag.

2. The double-walled drill string assembly of claim 1, wherein: one or more fixing pieces for connecting the outer cylinder and the inner cylinder are arranged in the second channel; when the fixing member includes a plurality of fixing members, the plurality of fixing members are arranged at intervals in the circumferential direction of the annular space.

3. The double-walled drill string assembly of claim 2, wherein: the fixture is helical extending in the axial direction of the double wall drill string.

4. The double-walled drill string assembly of claim 2, wherein: said fastener being disposed through the annulus in the axial direction of said drill string unit;

alternatively, the length of the fixing extending in the axial direction of the drill string unit is smaller than the axial length of the annulus.

5. The double-walled drill string assembly of claim 2, wherein: the fixing piece is connected with the inner barrel through at least one connection form of embedding, anchoring and welding; the fixing piece is connected with the outer cylinder through a fastening piece.

6. The double wall drill string assembly of any of claims 1-5, wherein: the end part of the outer barrel is provided with a connecting flange, and the outer barrels of the adjacent drill string units are connected through the connecting flange.

7. The double-walled drill string assembly of claim 1, wherein: the drill bit matrix is larger in diameter than the outer cylinder and comprises one or more fluid channels communicated with the inner cylinder and one or more slag channels communicated with the annular space.

8. The double-walled drill string assembly of claim 7, wherein: one or more lifting lugs are arranged at the upper end of the drill bit matrix, and the sum of the bearing capacity of the one or more lifting lugs is larger than the weight of the drill bit matrix.

9. The double-walled drill string assembly of claim 7, wherein: the drill bit matrix lower extreme is equipped with the drill bit of a plurality of interval arrangements, a plurality of drill bits include first group drill bit and second group drill bit, and the diameter of first group drill bit is less than the diameter of second group drill bit, and the distance of first group drill bit distance from double-walled drill string subassembly axis is close to the distance of second group drill bit distance from double-walled drill string central axis.

10. A drilling apparatus, comprising: the double-walled drill string assembly of any one of claims 1-9, a drive, a compressor, a drilling platform, and drilling fluid circulation equipment; the drive device is configured to rotate the double-walled drill string component; the drilling platform comprises a lifting device configured to move the double-walled drill string component; the drilling fluid circulation apparatus is configured to input drilling fluid to the double-walled drill string assembly; the compressor is configured to be capable of injecting a compressed fluid into the double walled drill string assembly.

11. A method of drilling, the method comprising: the double-walled drill string assembly of any of claims 1-9 having a top portion for injecting fluid into the first passage to create pressure at the bottom bit matrix to force seawater from the bit matrix into the second passage back to the surface.

Technical Field

Embodiments of the present invention relate to, but are not limited to, the field of offshore drilling technologies, and more particularly, to a double-walled drill string assembly, a drilling apparatus, and a drilling method.

Background

Along with the increasing demand of green energy, the exploration and the use of the offshore green energy are more and more emphasized in various countries, and unconventional offshore facilities, high-power wind power devices, ocean energy (tidal energy and wave energy) devices and the like are researched and developed. However, severe environmental conditions and shallow geological conditions at sea place new demands for installation, operation, and the like of these facilities.

Generally, the installation of an offshore facility requires that a well bore with a certain depth and a certain size is drilled on the seabed, and then a pile foundation of the facility is fixed in the well bore by means of cement, anchoring and the like. As the size of offshore facilities increases, the diameter and depth of the required wellbore also increases. Conventional offshore oil production platforms typically operate more efficiently by hammering or pressing legs into the sea bed by piling. However, if the shallow layer of the seabed has a strong rock stratum, the offshore platform can only be used for drilling, and if the diameter of the drilled hole is small, for example, less than 1 meter, the efficiency and the cost of drilling by the offshore platform are half acceptable. If the diameter of the drill hole is larger, the operation efficiency is low, the operation cost is high, and the operation requirement cannot be met.

Disclosure of Invention

Embodiments of the present invention provide a double-walled drill string assembly comprising one or more sequentially connected drill string units and a bit matrix cooperatively mounted with the one or more sequentially connected drill string units; the drill string unit comprises an outer cylinder and an inner cylinder sleeved in the outer cylinder, the inner cylinder is matched with the drill bit matrix to form a first channel for injecting fluid, and an annular gap between the outer cylinder and the inner cylinder is matched with the drill bit matrix to form a second channel for outputting slag.

The embodiment of the invention also provides drilling equipment, which comprises a double-wall drill string component, a driving device connected with the double-wall drill string component, a drilling platform, lifting equipment and drilling fluid circulating equipment; the drive device is configured to rotate the double-walled drill string component; the drilling platform and the lifting device are configured to drive the double-walled drill string component to move; a drilling fluid circulation apparatus is configured to input drilling fluid to the double-walled drill string assembly.

The invention also provides a method of drilling a well, comprising: fluid is injected into the first channel from the top of the double-walled drill string assembly, creating pressure at the bit matrix at the bottom, causing seawater to carry slag from the bit matrix into the second channel back to the surface.

Compared with the prior art, the embodiment of the invention forms the first channel for injecting the fluid by matching the inner cylinder with the drill bit matrix, and forms the second channel for outputting the slag body by matching the annular gap between the outer cylinder and the inner cylinder with the drill bit matrix, thereby improving the drilling efficiency.

In one exemplary embodiment, one or more fasteners are provided between the inner and outer barrels and are connected to the inner and outer barrels, thereby increasing the torque transmitted by the double-walled drill string assembly, meeting the requirements of large-aperture high-strength rock formation operation and being low in cost.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a schematic axial cross-sectional view of a double-walled drill string assembly in accordance with an embodiment of the present invention;

FIG. 2 is a schematic view of one form of a fastener of a double wall drill string assembly in accordance with an embodiment of the present invention;

FIG. 3 is a schematic view of another version of a fastener element of a double wall drill string assembly in accordance with an embodiment of the present invention;

FIG. 4 is a schematic axial cross-sectional view of a drill string unit in accordance with an embodiment of the present invention;

FIG. 5 is a view of one form of an end face of a drill string unit in accordance with an embodiment of the present invention;

FIG. 6 is another end view of a drill string unit in accordance with an embodiment of the present invention;

FIG. 7 is a schematic view of a drilling apparatus according to an embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments of the present invention may be arbitrarily combined with each other without conflict.

As shown in fig. 1-7, an embodiment of the present invention is a double-walled drill string assembly 100, said double-walled drill string assembly 100 comprising one or more sequentially connected drill string units 1, and a bit matrix 2 mounted in cooperation with said one or more sequentially connected drill string units 1. The drill string unit 1 comprises an outer barrel 10 and an inner barrel 20 sleeved inside the outer barrel 10. The inner cylinder 20 is fitted with the bit carcass 2 to form a first passage 201 for injecting a fluid. The annular gap between the outer cylinder 20 and the inner cylinder 10 is matched with the drill bit matrix 2 to form a second channel 101 for outputting slag. Wherein the fluid can be compressed gas, and the slag can be seawater, rock debris, mud and the like.

The first channel 201 for injecting fluid is formed by the matching installation of the inner cylinder 20 and the drill bit matrix 2 of the embodiment of the invention. The annular gap between the outer cylinder 20 and the inner cylinder 10 is matched with the drill bit matrix 2 to form a second channel 101 for outputting slag, so that a large amount of rock debris (slag) generated during drilling can be efficiently returned to the ground, and the problem that the rotation speed of a drill bit is influenced because the rock debris is low in upward return speed in an annular space and easy to settle back to the bottom of a well by adopting a conventional method for operation is avoided.

In an exemplary embodiment, at least one fixing member 4 connecting the outer cylinder 10 and the inner cylinder 20 is provided in the second passage 101.

According to the embodiment of the invention, one or more fixing pieces 4 for connecting the outer cylinder 10 and the inner cylinder 20 are arranged, so that the torque of the double-wall drill string component 100 is increased, the operation requirement of a large-aperture high-strength rock stratum can be met, the conventional slow construction progress is improved into efficient drilling, and meanwhile, the cost is low.

In some exemplary embodiments, the fixing 4 is arranged throughout the annulus in the axial direction of the drill string unit 1.

In other exemplary embodiments, the length of the fixing 4 extending in the axial direction of the drill string unit 1 is smaller than the axial length of the annulus.

In an exemplary embodiment, as shown in FIG. 2, the fastener 4 is in the form of a straight plate extending a length along the axis of the double wall drill string assembly 100.

In another exemplary embodiment, as shown in FIG. 3, the fastener 4 is helical and extends a length rotationally along the axis of the double wall drill string assembly 100.

According to the embodiment of the invention, the spiral fixing piece 4 is arranged, so that rock debris can be pushed to return to the well from the bottom of the well, and the circulation capacity is greatly improved.

In an exemplary embodiment, the fixture 4 is coupled to the inner barrel 20 by at least one of an insert, an anchor, and a weld.

In an exemplary embodiment, one end of the fixing member 4 is connected to the inner cylinder 20 by means of an insert. Wherein, the form of inlaying can be for inner tube 20 lateral surface sets up the keyway, and the one end of mounting 4 is installed fixedly in the keyway. In other embodiments, the securing member 4 can be connected to the inner barrel 20 by an anchor, a weld, or the like.

In an exemplary embodiment, as shown in fig. 4, the other end of the fixing member 4 is connected to the outer cylinder by a fastening member 41. The fastening member 41 may be a bolt, and in other embodiments, a screw may be used as the fastening member to connect with the outer cylinder 10.

In an exemplary embodiment, as shown in fig. 4, the end of the outer barrel 10 of each drill string unit 1 is provided with a connecting flange 102 and a locking block (not shown), and the connecting flanges 102 of two adjacent outer barrels 10 are fixed by the locking block for realizing the serial connection and fixation of a plurality of outer barrels 10.

In another exemplary embodiment, the connecting flanges 102 of two adjacent outer barrels 10 are fixed by screws. In some exemplary embodiments, each drill string unit 1 is provided with one or more of said fasteners 4, and when a plurality of fasteners 4 are arranged, the plurality of fasteners 4 are arranged at intervals in the circumferential direction of the drill string unit 1.

In an exemplary embodiment, as shown in fig. 5, each drill string unit 1a includes four fasteners 4 and is spaced circumferentially along the drill string unit 1 a.

In another exemplary embodiment, as shown in fig. 6, each drill string unit 1b comprises three fasteners 4 and is spaced circumferentially along the drill string unit 1 b.

In an exemplary embodiment, the inner barrels 20 of adjacent drill string units 1 are plug connected, and the ends of the adjacent inner barrels 20 are respectively provided with a plug connector and a socket for plug connection.

In an exemplary embodiment, a sealing structure is provided between adjacent outer cylinders 10 and between adjacent inner cylinders 20.

In one exemplary embodiment, as shown in fig. 4, the sealing structure of the outer tub 10 is a first side seal 103 provided at an end of the outer tub 10.

In an exemplary embodiment, as shown in FIG. 4, the sealing structure of the inner cartridge 20 is a second side seal 202 disposed within the inner cartridge 20.

In another exemplary embodiment, the sealing structure of the inner barrel 20 can also be a plug structure disposed at the end of the inner barrel 20.

As shown in fig. 1, one or more lifting lugs (not shown) are arranged at the upper end of the bit carcass 2, and the sum of the bearing capacity of the one or more lifting lugs is larger than the weight of the bit carcass.

The drill bit matrix 2 comprises one or more fluid passages 22 and one or more slag passages 21, the inner cylinder 20 is communicated with the one or more fluid passages 22 to form a first passage 201, and the annular space between the inner cylinder 20 and the outer cylinder 10 is communicated with the one or more slag passages 21 to form a second passage 101. The diameter of the bit carcass 2 is larger than the diameter of the outer cylinder 10 so that a third passage is formed between the outer cylinder 10 and the wellbore. Illustratively, the drill bit matrix 2 has a diameter of more than 4 m and the outer cylinder 10 has a diameter of less than 1 m. A weighted cylinder may be provided outside the flange 102 of the outer barrel 10 to increase the weight on bit of the bit carcass 2. The lower end of the drill bit matrix 2 is provided with a plurality of drill bits 23, a group of small drill bits (a first group of drill bits) 23 close to the central line of the drill bit matrix 2 meets the requirement of low-speed large drilling pressure, and a group of large drill bits (a second group of drill bits) 23 far away from the central line meets the requirement of high-speed small drilling pressure.

As shown in fig. 1, the drill string assembly 100 further includes a rotary sealing sleeve 5 disposed on the upper portion of the outer cylinder 10 and a discharge pipe 51 connected to the sealing sleeve 5. The discharge pipe 51 can communicate with the second passage 101 and discharge the slag when the rotary seal sleeve 5 rotates. The seawater, debris, etc. in the outer tub 10 can be discharged with the aid of a pump. In the present embodiment, the rotary seal sleeve 5 is provided above sea level, but in other embodiments, the rotary seal sleeve 5 may be provided below sea level.

The embodiment of the invention also provides a well drilling method, which comprises the following steps: fluid is injected into the first passage 201 from the top of the double-walled drill string assembly 100, creating pressure at the bit carcass 2 at the bottom, causing seawater to carry slag from the bit carcass 2 into the second passage 101, back to the surface. Wherein the injected fluid may be a light gas.

During drilling operation, the driving device 3 at the top of the drilling platform 40 drives the double-wall drill string component 100 and the drill bit matrix 2 to rotate through the gear box 6 to form rock breaking, compressed air is injected into the inner cylinder 20 through the central pipe 7, and enters the bottom of the drill bit matrix 2 along the fluid channel 22 after reaching the drill bit matrix 2, and then enters an annular space (annular gap) of the double-wall drill string component 100 through the slag channel 21 to drive seawater and rock debris in a third channel 131 formed between the outer cylinder 10 and the shaft 13 to move upwards along a second channel 101, and then are discharged out of the shaft 13 through the rotary sealing sleeve 5 and the external pipeline 11.

The drilling method provided by the embodiment of the invention can realize high-efficiency drilling, and can efficiently return a large amount of rock debris (slag) generated during drilling to the ground, thereby avoiding the problem that the rotation speed of a drill bit is influenced because the rock debris returns to the bottom of a well easily due to slow upward return speed in an annular space by adopting a conventional method for operation. While the second passage 101 can control the upward speed of the cuttings. Therefore, the method can be suitable for the requirement of high-efficiency drilling with large aperture.

As shown in fig. 1 and 7, embodiments of the present invention also provide a drilling apparatus 1000 comprising a double walled drill string assembly 100, a drive 3, a compressor, a drilling platform 12, and drilling fluid circulation equipment. The drive means 3 is configured to rotate the double-walled drill string assembly 100. The drilling platform 12 includes a lifting apparatus configured to move the double-walled drill string assembly 100. The drilling fluid circulation device is configured to input drilling fluid to the double-walled drill string assembly 100. The compressor is configured to be capable of injecting a compressed fluid into the double walled drill string assembly 100. The top of the inner barrel 20 of the double-walled drill string assembly 100 is connected with the central tube 7 of the drive means 3 at the top of the drilling platform, the top of the outer barrel 10 of the double-walled drill string 1 is connected with the gear box 6 of the drive means 3 at the top of the drilling platform, the upper part of the outer barrel 10 is connected with the rotary sealing sleeve 5, and the rotary sealing sleeve 5 is arranged at a proper position of the drilling platform 12.

The drilling equipment 1000 in the embodiment of the invention further comprises an analysis device 14 which can analyze the rate of the discharged rock debris by utilizing the rock debris content and modify the suspension force and air displacement of the platform top drive on the drill string system in real time according to the rate.

Typically, drill bit casings used in conventional drilling of harder formations have a diameter of about 600mm and double wall drill strings have an outer diameter of up to about 175 mm. In offshore shallow hard rock operation, the diameter of a used drill bit matrix can reach 6000mm, even 9000mm, so that the torque transmitted to the drill bit matrix through a drill string is far greater than that of conventional operation, and the double-wall drill string component 100 provided by the embodiment of the invention can meet the operation requirement of a large-aperture high-strength rock stratum by arranging the fixing piece 4.

In the description of the embodiments of the present invention, the term "plurality" means two or more. In the description of the embodiments of the present invention, it should be noted that the terms "upper", "lower", "one side", "the other side", "one end", "the other end", "side", "opposite", "four corners", "periphery", "mouth" word structure ", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the structures referred to have specific orientations, are configured and operated in specific orientations, and thus, are not to be construed as limiting the present invention.

In the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "connected," "directly connected," "indirectly connected," "fixedly connected," "mounted," and "assembled" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; the terms "mounted," "connected," and "fixedly connected" may be directly connected or indirectly connected through intervening media, or may be connected through two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.