Reverse circulation concentric pipe-following reaming assembly, drilling tool and drilling method

Abstract

The invention provides a reverse circulation concentric follow-pipe reaming assembly, a drilling tool and a drilling method. The reaming assembly comprises a reaming sleeve and a pipe shoe rotationally arranged outside the reaming sleeve in a sleeving mode. The reaming sleeve comprises a connecting pipe section and a reaming pipe section, an annular groove is formed in the outer wall of the connecting pipe section, a convex ring table is arranged at one end of the pipe shoe, and the convex ring table is rotatably arranged in the annular groove; the other end of the pipe shoe extends out of the reaming sleeve; a plurality of reaming teeth are arranged at the end part, far away from the connecting pipe section end, of the reaming pipe section; at least two lugs are arranged on the inner wall of the reaming sleeve and correspond to slag discharge grooves in the reverse circulation drill bit, the inner diameter of each lug is larger than the corresponding outer diameter of the outer contour of the corresponding slag discharge groove, and the lugs are used for being matched with grooves in the reverse circulation drill bit. The drilling tool comprises a reverse circulation drill bit, a follow pipe and a reaming assembly. A groove is formed in the outer wall of the reverse circulation drill bit. The lug is operably arranged in the groove; one end of the follow pipe is connected with the pipe shoe; under the condition of complex geology, geological exploration and geological information acquisition can be realized at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of drilling equipment, and in particular to a reverse circulation concentric follow-up tube reaming component, a drilling tool and a drilling method. Background Art

[0002] Existing reverse circulation drill bits are mainly used for geological exploration and other construction. Under complex geological conditions, conventional reverse circulation drill bits are difficult to drill holes and difficult to collect geological information; and conventional drill bits cannot achieve the purpose of geological exploration.

[0003] Therefore, there is an urgent need for a reverse circulation concentric follow-up tube expansion assembly, drilling tools and drilling methods that can simultaneously realize geological exploration and geological information collection under complex geological conditions. Summary of the invention

[0004] The purpose of the present invention is to provide a reverse circulation concentric follow-tube reaming assembly, a drill tool and a drilling method, aiming to solve the technical problem that traditional reverse circulation drill tools cannot simultaneously realize geological exploration and geological information collection under complex geological conditions.

[0005] To achieve the above-mentioned object, in a first aspect, the present invention provides a reverse circulation concentric heel-tube reaming assembly, comprising a reaming sleeve and a pipe shoe rotatably sleeved on the outside of the reaming sleeve;

[0006] The expansion sleeve comprises a connecting pipe section and an expansion pipe section which are connected in a continuous manner.

[0007] The outer wall of the connecting pipe section is provided with an annular groove, one end of the pipe shoe is provided with a convex ring platform, and the convex ring platform can be rotatably arranged in the annular groove; the other end of the pipe shoe extends out of the expansion sleeve for connecting with the heel pipe;

[0008] The end of the reaming pipe section away from the connecting pipe section end is provided with a plurality of reaming teeth, and the plurality of reaming teeth are evenly spaced along the circumference of the reaming sleeve;

[0009] The inner wall of the reaming sleeve is provided with at least two lugs, which are arranged corresponding to the slag discharge groove on the reverse circulation drill bit, and the inner diameter of the lug is larger than the outer diameter corresponding to the outer contour of the slag discharge groove. The lug is used to match the groove on the reverse circulation drill bit so that the reverse circulation concentric follow-up tube reaming assembly does not rotate during the drilling process.

[0010] As a further improvement of the above scheme, the outer surface of the reaming pipe section is a conical surface, and its cross-sectional diameter gradually increases from the connecting pipe section toward the reaming teeth.

[0011] As a further improvement of the above solution, the end of the reaming pipe section away from the connecting pipe section end has a first reaming annular surface and a second reaming annular surface, and the first reaming annular surface and the second reaming annular surface are arranged at a preset angle;

[0012] The first reaming annular surface and / or the second reaming annular surface are provided with a plurality of mounting holes for arranging the reaming teeth.

[0013] As a further improvement of the above scheme, the mounting holes on the first reaming annular surface and the second reaming annular surface are staggered and evenly spaced along the circumferential direction of the reaming sleeve.

[0014] As a further improvement of the above solution, the expansion sleeve and the pipe boot are rotatably connected by heat treatment extrusion.

[0015] As a further improvement of the above solution, the hole-expanding tooth is installed in the installation hole by cold pressing.

[0016] In a second aspect, the present invention further provides a reverse circulation concentric pipe drilling tool, comprising a reverse circulation drill bit, a pipe, and a reverse circulation concentric pipe reaming assembly as provided in the first aspect;

[0017] The reverse circulation drill bit comprises a drill bit body and a groove arranged on the outer wall of the drill bit body, and the groove entrance is consistent with the rotational orientation of the drill bit body;

[0018] The lug of the reverse circulation concentric heel-tube reaming assembly is operably matched and arranged in the groove to transmit power and torque;

[0019] One end of the heel pipe is connected to the other end of the pipe shoe of the reverse circulation concentric heel pipe reaming assembly.

[0020] As a further improvement of the above solution, at least one air inlet is provided on the side of the end of the drill body, and the air inlet is connected to an air inlet channel;

[0021] The end face of the drill body is provided with a slag discharge groove, and the slag discharge groove is connected to a slag discharge channel; the slag discharge channel includes a slag discharge main channel arranged in the drill body and along the axis of the drill body, and a slag discharge branch channel; one end of the slag discharge branch channel is connected to the slag discharge groove, and the other end is connected to the main slag discharge channel.

[0022] As a further improvement of the above scheme, the tooth surface of the reaming teeth of the reverse circulation concentric follow-tube reaming assembly is higher than the tooth surface of the drill bit body, forming a drilling structure with a sunken center.

[0023] As a further improvement of the above solution, the other end of the pipe shoe is threadedly connected or welded to one end of the heel pipe to form an integral whole.

[0024] As a further improvement of the above solution, the reverse circulation drill bit is connected to the impactor through a caliper sleeve and a clamping ring.

[0025] In a third aspect, the present invention further provides a drilling method for a reverse circulation concentric pipe drill as provided in the second aspect, the steps of which include:

[0026] S1, firstly align the lugs on the reverse circulation concentric tube reaming assembly with each slag discharge groove on the reverse circulation drill bit, and make the lugs sleeved on the outside of the reverse circulation drill bit; then, rotate the reverse circulation concentric tube reaming assembly forwardly, so that the lugs are correspondingly stuck in the grooves of the reverse circulation drill bit;

[0027] S2, connecting the heel pipe and the pipe shoe on the reverse circulation concentric heel pipe reaming assembly into one piece; connecting the impactor to the reverse circulation drill bit;

[0028] S3, start the drilling rig and make it rotate forward, the drilling rig provides a rotary torque and a propulsion force for the reverse circulation drill bit, and the reverse circulation drill bit transmits the rotary torque and the propulsion force to the reaming sleeve through the lug and groove connection structure to synchronously reame; the impactor provides shock waves and drilling pressure to break the rock formation at the bottom of the hole; the pipe shoe and the follower pipe do not rotate under the action of the friction resistance and the holding force of the rock formation, and only follow downward under the action of the thrust;

[0029] S4. When drilling is completed, the drilling rig rotates in the opposite direction, the reaming sleeve is relatively disengaged from the reverse circulation drill bit due to inertia and rock friction resistance, the lugs correspond to the slag discharge grooves one by one, and the reverse circulation drill bit is lifted out of the hole;

[0030] The reverse circulation concentric follower pipe reaming assembly and the follower pipe are left in the hole to protect the wall, and a conventional drill bit is replaced to continue drilling; or, if the exploration is completed, the reverse circulation concentric follower pipe reaming assembly and the follower pipe are simultaneously lifted out of the hole.

[0031] Since the present invention adopts the above technical solution, the beneficial effects of this application are:

[0032] 1. The present invention provides a reverse circulation concentric follow-up tube reaming assembly, comprising a reaming sleeve and a pipe shoe rotatably sleeved on the outside of the reaming sleeve; the inner wall of the reaming sleeve is provided with at least two lugs, the lugs are arranged corresponding to the slag discharge grooves on the reverse circulation drill bit, and the inner diameter of the lugs is larger than the outer diameter corresponding to the outer contour of the slag discharge grooves, the lugs are used to match the grooves on the reverse circulation drill bit, and the connection structure of the lugs and the grooves can, on the one hand, connect the reverse circulation concentric follow-up tube reaming assembly with the reverse circulation drill bit to transmit rotational torque and propulsion force, The reaming sleeve is enabled to perform reaming operations so as to collect geological information and achieve the purpose of geological exploration. On the other hand, after the drilling rig rotates in the opposite direction, the reverse circulation concentric follow-up pipe reaming assembly can be automatically disengaged from the reverse circulation drill bit, which is convenient for replacing a conventional drill bit for drilling operations; and the connection structure corresponding to the groove and the lug is easy to process; preferably, the reaming sleeve and the pipe boot are connected by heat treatment extrusion, which can not only achieve effective connection between the two, but also enable them to rotate with each other, so that while reaming is achieved, the follow-up pipe will not rotate and can only follow synchronously.

[0033] 2. The present invention provides a reverse circulation concentric follow-up tube drilling tool, comprising a reverse circulation drill bit, a follow-up tube, and a reverse circulation concentric follow-up tube reaming assembly as described in the first aspect; the reverse circulation drill bit comprises a drill bit body and a groove arranged on the outer wall of the drill bit body, and the groove entrance is consistent with the rotational orientation of the drill bit body; the lug of the reverse circulation concentric follow-up tube reaming assembly is operably matched and arranged in the groove to transmit power and torque; one end of the follow-up tube is connected to the other end of the pipe boot of the reverse circulation concentric follow-up tube reaming assembly; such an arrangement can realize geological exploration and geological information collection simultaneously under complex geological conditions; specifically, the lugs on the reverse circulation concentric follow-up tube reaming assembly are aligned with each slag discharge groove on the reverse circulation drill bit one by one, and the lugs are sleeved on the outside of the reverse circulation drill bit along the axial direction of the reverse circulation drill bit; then the reverse circulation concentric follow-up tube reaming assembly is rotated forward so that the lugs are correspondingly stuck in the grooves on the reverse circulation drill bit; The follower pipe is connected to the pipe shoe on the reverse circulation concentric follower pipe reaming assembly as a whole; the impactor is connected to the reverse circulation drill bit; the drilling rig is started and rotated forward, the drilling rig provides a rotary torque and a propulsion force for the reverse circulation drill bit, and the reverse circulation drill bit transmits the rotary torque and the propulsion force to the reaming sleeve through the lug and groove connection structure to perform synchronous reaming; the impactor provides shock waves and drilling pressure to break the rock formation at the bottom of the hole; the pipe shoe and the follower pipe are subjected to the friction resistance of the rock formation and the clamping force of the rock formation. The reverse circulation drill bit does not rotate downward, but only moves downward under the action of thrust; when drilling is completed, the drilling rig rotates in the opposite direction, the reaming sleeve is relatively disengaged from the reverse circulation drill bit under the action of inertia and rock friction resistance, the lugs correspond to the slag discharge grooves one by one, and the reverse circulation drill bit is lifted out of the hole; the reverse circulation concentric follower tube reaming assembly and the follower tube remain in the hole to protect the wall, and the conventional drill bit is replaced to continue drilling; or, if the exploration is completed, the reverse circulation concentric follower tube reaming assembly and the follower tube are lifted out of the hole at the same time;

[0034] In certain preferred embodiments, the tooth surface of the reaming teeth of the reverse circulation concentric follow-tube reaming assembly is higher than the tooth surface of the drill bit body, forming a center-sunken drilling structure; when working, the center-sunken drilling structure has good centering, smooth slag discharge (slag discharge in the center of the drill bit), stable operation and small vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0036] Figure 1It is a stereoscopic schematic diagram of a reverse circulation concentric tube reaming assembly disclosed in the present invention;

[0037] Figure 2 It is an exploded schematic diagram of a reverse circulation concentric follow-tube reaming assembly disclosed in the present invention;

[0038] Figure 3 It is a cross-sectional schematic diagram of a reverse circulation concentric tube reaming assembly disclosed in the present invention;

[0039] Figure 4 It is a cross-sectional schematic diagram of the hole expansion sleeve disclosed in the present invention;

[0040] Figure 5 It is a three-dimensional schematic diagram of the reverse circulation drill bit disclosed in the present invention;

[0041] Figure 6 A partial cross-sectional view of a reverse circulation concentric pipe drilling tool disclosed in the present invention Figure 1 ;

[0042] Figure 7 It is a side view schematic diagram of the reverse circulation drill bit disclosed in the present invention;

[0043] Figure 8 A partial cross-sectional view of a reverse circulation concentric pipe drilling tool disclosed in the present invention Figure 2 ;

[0044] Fig. 9 The present invention discloses a cross-sectional schematic diagram of a reverse circulation concentric follow-up pipe drilling process.

[0045] Reference numerals:

[0046] 1. Reverse circulation concentric follow-up tube reaming assembly; 11. reaming sleeve; 111. connecting pipe section; 112. reaming pipe section; 113. annular groove; 114. first reaming annular surface; 115. second reaming annular surface; 116. mounting hole; 12. pipe shoe; 121. convex ring platform; 13. reaming teeth; 14. lug;

[0047] 2. Reverse circulation drill bit; 21. Drill bit body; 22. Groove; 23. Slag discharge groove; 24. Air inlet;

[0048] 3. Follower tube; 4. Caliper cover; 5. Snap ring; 6. Impactor.

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0052] In addition, in the present invention, the descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0053] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] Example 1

[0055] See also Figure 1-Figure 5 The present invention provides a reverse circulation concentric heel pipe reaming assembly, comprising a reaming sleeve 11 and a pipe shoe 12 rotatably sleeved on the outside of the reaming sleeve 11;

[0056] The reaming sleeve 11 includes a connecting pipe section 111 and a reaming pipe section 112 which are connected in an integrated manner. Specifically, the connecting pipe section 111 and the reaming pipe section 112 are integrally formed, and the inner cavity of the reaming sleeve 11 is a through hole that runs through the length direction thereof;

[0057] The outer wall of the connecting pipe section 111 is provided with an annular groove 113, and one end of the pipe shoe 12 is provided with a convex ring platform 121, and the convex ring platform 121 is rotatably arranged in the annular groove 113; the other end of the pipe shoe 12 extends out of the reaming sleeve 11 for connecting with the heel pipe 3;

[0058] The end of the reaming pipe section 112 away from the end of the connecting pipe section 111 is provided with a plurality of reaming teeth 13, and the plurality of reaming teeth 13 are evenly spaced along the circumference of the reaming sleeve 11; specifically, in this embodiment, the reaming teeth 13 are alloy teeth, which are provided at the end by cold pressing and are used for reaming operation;

[0059] The inner wall of the reaming sleeve 11 is provided with at least two lugs 14, and the lugs 14 are arranged corresponding to the slag discharge grooves 23 on the reverse circulation drill bit 2, and the inner diameter of the lugs 14 is larger than the outer diameter corresponding to the outer contour of the slag discharge grooves 23, and the lugs 14 are used to match the grooves 22 on the reverse circulation drill bit 2, so that the reverse circulation concentric follow-up tube reaming assembly 1 does not rotate during the drilling process; in this embodiment, the reverse circulation drill bit 2 is evenly provided with three slag discharge grooves 23 around its circumference, and correspondingly, three lugs 14 are evenly distributed on the inner wall of the reaming sleeve 11, and the forward projection shape of the lugs 14 includes but is not limited to a rectangle or a square, and the outer wall of the reverse circulation drill bit 2 is provided with a groove 22 corresponding to the lug 14, and the entrance of the groove 22 is consistent with the rotational orientation of the reverse circulation drill bit 2; the connection structure of the lug 14 and the groove 22 The setting of the structure can, on the one hand, connect the reverse circulation concentric follow-up tube reaming assembly 1 with the reverse circulation drill bit 2 to transmit rotational torque and propulsion force, so that the reaming sleeve 11 can perform reaming operation to collect geological information and achieve the purpose of geological exploration; on the other hand, after the drilling rig rotates in the opposite direction, the reverse circulation concentric follow-up tube reaming assembly 1 can be automatically disengaged from the reverse circulation drill bit 2; since the inner diameter of the lug 14 is larger than the outer diameter corresponding to the outer contour of the slag discharge groove 23, the reverse circulation drill bit 2 can be raised to replace a conventional drill bit for drilling operation; and the connection structure corresponding to the groove 22 and the lug 14 is easy to process; preferably, the reaming sleeve 11 and the pipe boot 12 are connected by heat treatment extrusion, which can not only realize the effective connection between the two, but also enable them to rotate with each other, so that while realizing reaming, the follower tube 3 will not rotate but can only follow synchronously.

[0060] As a preferred embodiment, the outer surface of the reaming pipe section 112 is a conical surface, and its cross-sectional diameter gradually increases from the connecting pipe section 111 toward the reaming teeth 13. The setting of the conical surface makes the reaming operation proceed smoothly.

[0061] As a preferred embodiment, the end of the reaming pipe section 112 away from the end of the connecting pipe section 111 has a first reaming annular surface 114 and a second reaming annular surface 115, and the first reaming annular surface 114 and the second reaming annular surface 115 are arranged at a preset angle; the first reaming annular surface 114 and / or the second reaming annular surface 115 are provided with a plurality of mounting holes 116 for arranging the reaming teeth 13;

[0062] The setting of the preset angle makes the end of the expansion sleeve sharp-pointed, and facilitates the setting of expansion teeth 13 on the two expansion annular surfaces, thereby improving the expansion efficiency and expansion effect;

[0063] In certain preferred embodiments, the mounting holes 116 on the first reaming annular surface 114 and the second reaming annular surface 115 are staggered and evenly spaced along the circumference of the reaming sleeve 11; thereby, the reaming teeth 13 are staggered on the two reaming annular surfaces, which, on the one hand, ensures the mounting strength of the end, and on the other hand, allows more reaming teeth 13 to be arranged, thereby speeding up the reaming operation efficiency and reaming effect.

[0064] Embodiment 2:

[0065] See also Figure 6-Figure 8 The present invention further provides a reverse circulation concentric follow-up pipe drilling tool, comprising a reverse circulation drill bit 2, a follow-up pipe 3, and a reverse circulation concentric follow-up pipe reaming assembly 1 as provided in Example 1;

[0066] The reverse circulation drill bit 2 comprises a drill bit body 21 and a groove 22 arranged on the outer wall of the drill bit body 21, and the inlet of the groove 22 is consistent with the rotational orientation of the drill bit body 21;

[0067] See also Figure 8 The side surface of the end of the drill body 21 is provided with at least one air inlet 24, and the air inlet is connected to an air inlet channel (refer to the direction of arrow A); the end surface of the drill body 21 is provided with a slag discharge groove 23; see Figure 8 and Fig. 9 , a slag discharge channel is also provided in the drill body 21, and the slag discharge channel includes a slag discharge main channel and a slag discharge branch channel arranged along the axis of the drill body; one end of the slag discharge branch channel is connected to the slag discharge groove 23, and the other end is connected to the main slag discharge channel; in the present invention, the side air intake, end face and middle air outlet slag discharge are arranged at the end of the drill body 21, so that the rock slag generated during the exploration process enters the corresponding slag discharge branch channel through the slag discharge groove 23 and then enters the slag discharge main channel (see the direction of arrow B), which is convenient for collecting rock slag on the one hand, and on the other hand, it is only discharged through the slag discharge channel located inside the drill body, which can avoid rock slag pollution and can accurately collect geological information;

[0068] The lug 14 of the reverse circulation concentric heel tube reaming assembly 1 is operably matched and arranged in the groove 22 to transmit power and torque; one end of the heel tube 3 is connected to the other end of the pipe shoe 12 of the reverse circulation concentric heel tube reaming assembly 1;

[0069] When the lug 14 is correspondingly clamped in the groove 22 of the reverse circulation drill bit 2, the tooth surface of the reaming teeth 13 of the reverse circulation concentric follow-up tube reaming assembly 1 is higher than the tooth surface of the drill bit body 21, forming a drilling structure with a central depression, and the clamping structure of the lug 14 and the groove 22 can effectively transmit the rotary torque and propulsion force provided by the reverse circulation drill bit 2 connected to the drilling rig to the reaming sleeve 11, providing power for its reaming operation to complete geological exploration and geological information collection; after the geological exploration is completed, the reverse circulation drill bit 2 is rotated in the reverse direction, and the lug 14 is relatively disengaged from the groove 22 and corresponds one by one to the slag discharge groove 23 of the reverse circulation drill bit 2, so that the reverse circulation drill bit 2 can be lifted out, and then the conventional drill bit can be changed according to the actual situation to continue the drilling operation;

[0070] In certain preferred embodiments, the tooth surface of the reaming teeth 13 of the reverse circulation concentric follow-up tube reaming assembly 1 is higher than the tooth surface of the drill bit body 21, forming a center-sunken drilling structure; when working, the center-sunken drilling structure has good centering, smooth slag discharge (slag discharge in the center of the drill bit), stable operation and small vibration.

[0071] As a preferred embodiment, the other end of the pipe boot 12 is threadedly connected or welded to one end of the follower tube 3 to form an integral whole; preferably, the other end of the pipe boot 12 is provided with an external thread, and one end of the follower tube 3 is provided with an internal thread matching and connected to the external thread. During installation, it is only necessary to thread the other end of the pipe boot 12 and one end of the follower tube 3 to form an integral whole for operation, and the threaded connection method is used to facilitate installation and disassembly.

[0072] As a preferred embodiment, the reverse circulation drill bit 2 is connected to the impactor 6 through a caliper sleeve 4 and a clamp ring 5; the reverse circulation drill bit 2 is also connected to a drill rod at the end away from the drilling end, and the drill rod is connected to the drilling rig drive;

[0073] The reverse circulation drill bit 2 transmits the rotational torque and propulsion force to the reaming sleeve 11 for synchronous reaming through the connection structure of the lug 14 and the groove 22; the impactor 6 provides shock waves and drilling pressure to break the rock formation at the bottom of the hole; the pipe shoe 12 and the follower pipe 3 do not rotate under the action of the friction resistance of the rock formation and the clamping force of the rock formation, and only follow downward under the action of the thrust; the drilling tool provided by the present invention can adapt to the rock formation, and under complex geological conditions, it can still operate efficiently under the action of the impactor 6 and the drilling rig.

[0074] Embodiment 3:

[0075] See also Fig. 9 The present invention also provides a drilling method for a reverse circulation concentric pipe drill as provided in Example 2, the steps of which include:

[0076] S1. First, the lugs 14 on the reverse circulation concentric tube reaming assembly 1 are aligned with each slag discharge groove 23 on the reverse circulation drill bit 2, and the lugs 14 are sleeved on the outside of the reverse circulation drill bit 2 along the direction of the slag discharge groove 23; then, the reverse circulation concentric tube reaming assembly 1 is rotated forwardly, so that the lugs 14 are correspondingly stuck in the grooves 22 on the reverse circulation drill bit 2;

[0077] S2, connecting the follower pipe 3 and the pipe boot 12 on the reverse circulation concentric follower pipe reaming assembly 1 into one piece by welding or threading; connecting the impactor 6 to the reverse circulation drill bit 2 through the clamp sleeve and the clamp ring 5;

[0078] S3, start the drilling rig and rotate it forward, the drilling rig provides a rotary torque and a propulsion force for the reverse circulation drill bit 2, and the reverse circulation drill bit 2 transmits the rotary torque and the propulsion force to the reaming sleeve 11 through the lug 14 and the groove 22 connection structure to perform synchronous reaming; the impactor 6 provides a shock wave and a drilling pressure to break the bottom rock formation of the hole;

[0079] The pipe shoe 12 and the follower pipe 3 do not rotate under the action of rock formation friction resistance and rock formation clamping force, and only follow downward under the action of thrust; for details, see Fig. 9 a. The reverse circulation drill bit 2 is connected to the reverse circulation concentric follow-tube reaming assembly 1 to perform synchronous reaming operation to achieve geological exploration and geological information collection. The rock formation debris generated by the reaming operation is discharged through the slag discharge trough 23 to perform geological information analysis;

[0080] S4. When drilling is completed, the drilling rig rotates in the opposite direction, the reaming sleeve 11 is relatively disengaged from the reverse circulation drill bit 2 due to inertia and rock friction resistance, the lugs 14 correspond to the slag discharge grooves 23 one by one, and the reverse circulation drill bit 2 is lifted out of the hole. Fig. 9 b;

[0081] The reverse circulation concentric follow-up pipe reaming assembly 1 and the follow-up pipe 3 are left in the hole to protect the wall, and the conventional drill bit is replaced to continue drilling (see Fig. 9 c); or, if the exploration is completed, the reverse circulation concentric follower pipe reaming assembly 1 and the follower pipe 3 are simultaneously lifted out of the hole;

[0082] By adopting the drilling method provided by the present invention, it is only necessary to align the lugs 14 on the reverse circulation concentric follow-up tube reaming assembly 1 with each slag discharge groove 23 on the reverse circulation drill bit 2, and to sleeve the lugs 14 on the outside of the reverse circulation drill bit 2; then, the reverse circulation concentric follow-up tube reaming assembly 1 is rotated forwardly so that the lugs 14 are correspondingly clamped in the grooves 22 on the reverse circulation drill bit 2; the reverse circulation concentric follow-up tube reaming assembly 1 and the reverse circulation drill bit 2 can be easily installed. When the drilling rig rotates forwardly, the connection structure of the lugs 14 and the grooves 22 can effectively transmit the rotational torque and the propulsion force to the reaming sleeve 11 for synchronous reaming. The pipe shoe 12 and the follower pipe 3 do not rotate under the action of rock friction resistance and rock holding force, and only follow downward under the action of thrust, so that geological exploration and geological information collection can be achieved simultaneously under complex geological conditions; when drilling is completed, the drilling rig rotates in the opposite direction, and the reaming sleeve 11 is relatively disengaged from the reverse circulation drill bit 2 under the action of inertia and rock friction resistance, and the lug 14 corresponds to the slag discharge groove 23 one by one, so that the reverse circulation drill bit 2 is lifted out of the hole, and the follower pipe can be recovered at the same time; the entire drilling process, on the basis of being able to simultaneously achieve geological exploration and geological information collection, is easy to install and operate, and has high drilling efficiency.

[0083] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A reverse circulation concentric tube expansion assembly, characterized in that: It comprises a reaming sleeve and a pipe shoe rotatably sleeved on the outside of the reaming sleeve; The expansion sleeve comprises a connecting pipe section and an expansion pipe section which are connected in a continuous manner. The outer wall of the connecting pipe section is provided with an annular groove, one end of the pipe shoe is provided with a convex ring platform, and the convex ring platform can be rotatably arranged in the annular groove; the other end of the pipe shoe extends out of the expansion sleeve for connecting with the heel pipe; The end of the reaming pipe section away from the connecting pipe section end is provided with a plurality of reaming teeth, and the plurality of reaming teeth are evenly spaced along the circumference of the reaming sleeve; The inner wall of the reaming sleeve is provided with at least two lugs, which are arranged corresponding to the slag discharge groove on the reverse circulation drill bit, and the inner diameter of the lug is larger than the outer diameter corresponding to the outer contour of the slag discharge groove. The lug is used to match the groove on the reverse circulation drill bit so that the reverse circulation concentric follow-up tube reaming assembly does not rotate during the drilling process.

2. A reverse circulation concentric tube reaming assembly according to claim 1, characterized in that: The outer surface of the reaming pipe section is a conical surface, and the cross-sectional diameter thereof gradually increases from the connecting pipe section toward the reaming teeth.

3. A reverse circulation concentric tube reaming assembly according to claim 1 or 2, characterized in that: The end of the reaming pipe section away from the connecting pipe section end has a first reaming annular surface and a second reaming annular surface, and the first reaming annular surface and the second reaming annular surface are arranged at a preset angle; The first reaming annular surface and / or the second reaming annular surface are provided with a plurality of mounting holes for arranging the reaming teeth.

4. A reverse circulation concentric tube reaming assembly according to claim 3, characterized in that: The mounting holes on the first reaming annular surface and the second reaming annular surface are staggered and evenly spaced along the circumferential direction of the reaming sleeve.

5. A reverse circulation concentric tube reaming assembly according to claim 1 or 2, characterized in that: The expansion sleeve and the pipe shoe are rotatably connected by heat treatment and extrusion.

6. A reverse circulation concentric pipe drilling tool, characterized in that: It comprises a reverse circulation drill bit, a follower pipe, and a reverse circulation concentric follower pipe reaming assembly as claimed in any one of claims 1 to 5; The reverse circulation drill bit comprises a drill bit body and a groove arranged on the outer wall of the drill bit body, and the groove entrance is consistent with the rotational orientation of the drill bit body; The lug of the reverse circulation concentric heel-tube reaming assembly is operably matched and arranged in the groove to transmit power and torque; One end of the heel pipe is connected to the other end of the pipe shoe of the reverse circulation concentric heel pipe reaming assembly.

7. A reverse circulation concentric pipe drilling tool according to claim 6, characterized in that: The tooth surface of the reaming teeth of the reverse circulation concentric follow-tube reaming assembly is higher than the tooth surface of the drill bit body, forming a drilling structure with a sunken center.

8. A reverse circulation concentric pipe drilling tool according to claim 6 or 7, characterized in that: The other end of the pipe shoe is threadedly connected or welded to one end of the heel pipe to form an integral whole.

9. A reverse circulation concentric pipe drilling tool according to claim 6 or 7, characterized in that: At least one air inlet is provided on the side of the end of the drill body, and the air inlet is connected to an air inlet channel; The end face of the drill body is provided with a slag discharge groove, and the slag discharge groove is connected to a slag discharge channel; the slag discharge channel includes a slag discharge main channel arranged in the drill body and along the axis of the drill body, and a slag discharge branch channel; one end of the slag discharge branch channel is connected to the slag discharge groove, and the other end is connected to the main slag discharge channel.

10. A drilling method using a reverse circulation concentric drill bit as claimed in any one of claims 6 to 9, characterized in that: The steps include: S1, firstly align the lugs on the reverse circulation concentric tube reaming assembly with each slag discharge groove on the reverse circulation drill bit, and make the lugs sleeved on the outside of the reverse circulation drill bit; then, rotate the reverse circulation concentric tube reaming assembly forwardly, so that the lugs are correspondingly stuck in the grooves of the reverse circulation drill bit; S2, connecting the heel pipe and the pipe shoe on the reverse circulation concentric heel pipe reaming assembly into one piece; connecting the impactor to the reverse circulation drill bit; S3, start the drilling rig and make it rotate forward, the reverse circulation drill bit transmits the rotation torque and propulsion force to the reaming sleeve through the lug and groove connection structure to synchronously reame; the impactor provides shock waves and drilling pressure to break the rock formation at the bottom of the hole; the pipe shoe and the follower pipe do not rotate under the action of rock formation friction resistance and rock formation clamping force, and only follow downward under the action of thrust; S4. When drilling is completed, the drilling rig rotates in the opposite direction, the reaming sleeve is relatively disengaged from the reverse circulation drill bit due to inertia and rock friction resistance, the lugs correspond to the slag discharge grooves one by one, and then the reverse circulation drill bit is lifted out of the hole; The reverse circulation concentric follower pipe reaming assembly and the follower pipe are left in the hole to protect the wall, and a conventional drill bit is replaced to continue drilling; or, if the exploration is completed, the reverse circulation concentric follower pipe reaming assembly and the follower pipe are simultaneously lifted out of the hole.

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