CN216922030U - Continuous casing drilling tool system with double impregnated diamond drill bits - Google Patents

Abstract

A continuous casing drilling tool system with double impregnated diamond drill bits comprises an inner drill bit, an outer drill bit, a drill rod, a casing joint, a casing and the like, wherein the inner drill bit is driven to rotate by the drill rod and provide a drilling pressure, the outer drill bit is driven to rotate by the inner drill bit through a transmission key, the drilling pressure can be provided by the casing or by the drill rod under the combined action of the limit of the inner drill bit and the limit of the outer drill bit, the independent rotation function of the outer drill bit and the casing on the upper part of the outer drill bit can be realized through the design of a plurality of pressure bearing bearings and a guide bearing, the characteristic spiral grooves on the surface of the casing are beneficial to the rotation and the unfreezing of a crushed stratum when the casing is clamped under the action of friction force, the high casing body design of the inner drill bit and the outer drill bit can increase the drilling depth, the casing following depth is further improved, the continuous following drilling is realized, the friction between the casing and the hole wall is always expressed as dynamic friction, the energy loss can be significantly reduced relative to the static friction generated when the drill is stopped.

Description

Continuous casing drilling tool system with double impregnated diamond drill bits

Technical Field

The invention belongs to the technical field of deep drilling construction, and particularly relates to a continuous casing drilling tool system with double diamond-impregnated bits.

Background

In order to improve the stability and construction efficiency of drilling the hole wall in broken stratums such as cobble and gravel, the hole wall is usually maintained to be stable by adopting a casing drilling technology, and the effect is obvious. At present, the conventional pipe-following drilling technology mainly adopts a down-the-hole hammer pipe-following drilling mode under a gas environment, and has two modes: one is eccentric casing drilling, and the other is concentric casing drilling. Eccentric pipe-following creeps into through the vibration impact effect of impacter in the drilling tool combination, drives eccentric drilling tool and drills, because eccentric drilling tool receives centrifugal force and the effect of friction power during the drilling, eccentric drill bit outwards deviates out to reach the mesh of enlarged aperture, the impact effect of stabilizer in the rethread drilling tool combination drives the sleeve pipe and follows up, and the inside detritus that produces of drilling is blown out outside the hole by the air compressor machine through the keyway on the stabilizer. After the drilling is finished, the eccentric wheel is folded back into the sleeve by reversing, the sleeve is lifted out of the sleeve, and the sleeve is left in the hole to protect the wall so as to form the hole; the concentric simultaneous drilling is characterized in that the concentric simultaneous drilling impacts broken rock to form a hole through a central drill bit and a concentric sleeve sleeved outside the central drill bit, the sleeve is brought into the hole by using the reaming effect of the concentric sleeve, a key groove is formed in the concentric sleeve, and the central drill bit reversely rotates to exit through the concentric sleeve after bedrock. The concentric pipe follow can better solve the problems of drill jamming and boulder drilling caused by complex geological conditions during eccentric pipe follow drilling, is more beneficial to construction operation and improves the drilling efficiency.

However, the above two conventional methods are only suitable for drilling in a shallow depth of 100 meters, and as the well depth increases, the friction resistance between the casing and the well wall increases due to irregular drilling wall of impact rotary drilling in a gas environment, and the stratum is broken, so that the drilling is very easy to block. Particularly for drilling on the hot dry rock, the buried depth of the hot dry rock is more than kilometer, and the wall of the hot dry rock well is greatly stressed by thermal stress and shock cooling, so that the hot dry rock well is easy to crack and block. Therefore, the existing impact casing drilling technology and process cannot meet the requirements of deep well drilling of fractured formations.

In order to solve the problems, a research on a casing drilling system with a wall protection function in a slurry environment needs to be developed, and the purpose of continuously drilling a broken stratum and a dry and hot rock stratum of a deep well with a casing can be theoretically realized by adopting a double-impregnated diamond bit. Therefore, the significance of innovatively researching the continuous casing drilling tool system with the diamond-impregnated bit in the slurry environment is great.

Disclosure of Invention

The invention provides a continuous casing drilling tool system with double diamond-impregnated bits, and aims to realize deep well crushing and continuous casing drilling in hot dry rock formations.

A double-impregnated diamond bit continuous casing drilling tool system comprises an inner bit, an outer bit, a first transmission key, a second transmission key, an inner bit limit, an outer bit limit, a first copper sleeve, a second copper sleeve, an outer bit joint, an inner bit joint, a spring plate, an inner sealing element, an outer sealing element, a lower pressure bearing, a middle pressure bearing, an upper pressure bearing, a lower pilot bearing limit, an upper pilot bearing limit, a pilot bearing, an outer bit joint limit, a drill rod, a casing joint and a casing;

the inner drill bit is different from a conventional diamond-impregnated drill bit, a specific structure exists, the upper end of the inner drill bit is fixedly connected with the lower end of an inner drill bit joint, the upper end of the inner drill bit joint is fixedly connected with the lower end of a drill rod, N first key grooves are circumferentially and uniformly distributed on the outer side of the inner drill bit, N is larger than or equal to 1, N second key grooves are circumferentially and uniformly distributed on the inner side of the inner drill bit limit, N is larger than or equal to 1, N first transmission keys are fixed between the first key grooves and the second key grooves, and N is larger than or equal to 1;

the outer drill bit is different from a conventional diamond-impregnated drill bit and has a specific structure, N third keyways are circumferentially and uniformly distributed on the inner side of the outer drill bit, N is more than or equal to 1, N fourth keyways are circumferentially and uniformly distributed on the outer side of the limit of the outer drill bit, N is more than or equal to 1, and N second transmission keys are fixed between the third keyways and the fourth keyways;

the outer side of the inner drill bit limit is circumferentially and uniformly provided with N first lugs, N is more than or equal to 1, the inner side of the outer drill bit limit is circumferentially and uniformly provided with N second lugs, N is more than or equal to 1, the bottom of the inner side of the outer drill bit limit is provided with a first boss, the inner drill bit limit and the outer drill bit limit are coaxially and rotatably connected, the first lugs are limited at the upper ends of the first bosses, and when the inner drill bit limit rotates, the first lugs are in abutting engagement with the second lugs, so that the inner drill bit limit rotates and further drives the outer drill bit to limit and circumferentially rotate;

the lower end of an outer drill bit joint is fixedly connected with the upper end of an outer drill bit, a plurality of mud holes penetrating into the outer drill bit joint are circumferentially and uniformly distributed on the outer drill bit joint, a first threaded interface, a first groove and a second groove are further arranged on the outer drill bit joint, the outer wall of a first copper sleeve is fixedly connected with the first threaded interface through threads, an elastic sheet is arranged in the second groove, an inner sealing element is arranged in the first groove, the limiting lower end of the outer drill bit joint is fixedly connected with the upper end of the outer drill bit joint, the inner drill bit joint is fixedly connected with a second copper sleeve, the second copper sleeve is limited at the upper end of the first copper sleeve, the first copper sleeve and the second copper sleeve can rotate coaxially, a spatial annular gap between the outer drill bit joint and the inner drill bit joint is sealed, and the inner diameter of the first copper sleeve is smaller than the outer diameter of the second copper sleeve;

the lower end of the sleeve is fixedly connected with the upper end of the sleeve joint, the sleeve joint is provided with a third groove and a fourth groove, the lower guide bearing limit and the upper guide bearing limit are fixedly connected with the sleeve joint, the upper end and the lower end of the guide bearing inner ring are respectively pressed on the upper end surface of the lower guide bearing limit and the lower end surface of the upper guide bearing limit, the guide bearing outer ring is fixedly connected with the inner wall of the outer drill bit joint, the upper surface of the lower bearing is tightly connected with the lower end surface of the lower guide bearing limit, the lower surface of the lower bearing is tightly contacted with the upper end surface of the elastic piece, the upper end of the inner sealing piece is tightly contacted with the lower end surface of the sleeve joint, the lower surface of the middle bearing is tightly contacted with the upper surface of the upper guide bearing limit, the upper surface of the middle bearing is tightly contacted with the lower surface of the inner side of the outer drill bit joint limit, the upper bearing is arranged in the third groove, and the lower surface of the upper bearing is tightly contacted with the upper surface of the outer drill bit joint limit, the outer sealing piece is installed in the fourth groove, and the outer sealing piece is in close contact with the upper surface of the limiting outer side of the outer drill bit joint.

Furthermore, when the sleeve is clamped by broken rocks, the sleeve is rotationally driven by ground equipment, so that the sleeve is rotationally unlocked by the characteristic spiral groove structure on the surface of the sleeve in rotation.

Furthermore, when the first lug outside the inner bit limit contacts the second lug inside the outer bit limit, the inner bit water gap of the inner bit is aligned with the water gap of the outer bit.

Further, the path of the mud circulation during drilling is: and the mud flows out of the inner drill bit, flows through the inner drill bit water gap and the outer drill bit water gap at the bottom of the outer drill bit, enters an annular space formed by the outer drill bit and the hole wall, finally enters an annular space formed by the drill rod and the sleeve through the mud hole on the outer drill bit joint, and completes the whole circulation.

Further, the path of the mud circulation during drilling is: a part of slurry flows out of the inner drill bit, flows through the inner drill bit water gap and the outer drill bit water gap at the bottom of the outer drill bit, enters an annular space formed by the outer drill bit and the hole wall, and finally enters an annular space gap formed by the drill rod and the sleeve through a slurry hole on the outer drill bit joint;

the rest part flows out from the inner drill bit, passes through a water gap of the inner drill bit, enters an annular space formed by the inner drill bit and the outer drill bit, flows out from a water gap of the outer drill bit at the upper part of the outer drill bit, enters an annular space formed by the outer drill bit and the hole wall, and finally enters an annular space gap formed by the drill rod and the casing through a mud hole on the joint of the outer drill bit, so that the whole circulation is completed.

The invention has the beneficial effects that:

1. the rock debris generated by the rotary drilling of broken rocks by the diamond-impregnated double drill bit is smaller, so that the problem that the annular space between the inner and outer pipe assemblies drilled by the concentric casing pipe is clamped by large rock debris and can not normally rotate can be effectively solved;

2. the high-frequency low-amplitude impact rock breaking is combined, disturbance to a well wall is small, deep interference to the broken well wall is reduced, the hole wall is more regular, the drill bit and the sleeve independently rotate, the blocking probability is small, even if blocking occurs, the wrapping capacity of the well wall to the sleeve is weak due to the relative regularity of the well wall, the blocking degree is relatively low, and the blocking releasing capacity of the drilling tool system is improved;

3. the inner drill bit is driven to rotate by the drill rod, and the outer drill bit is driven to rotate by the inner drill bit through the transmission key. The inner drill bit and the outer drill bit are diamond-impregnated drill bits, disturbance to a well wall is small in the drilling process relative to down-the-hole hammer drilling, the hole wall is complete, the blocking probability is small, the degree is low, the high matrix design of the inner drill bit and the outer drill bit can greatly improve the drilling depth, further improve the pipe following depth, realize continuous pipe following drilling, stop drilling in midway until the service life of the drill bits is reached or the designed pipe following depth is reached;

4. in the process of continuous pipe-following drilling, the sleeve and the hole wall always show dynamic friction, and the energy loss is relatively small. The inner drill bit provides the bit pressure through the drill rod, and the outer drill bit can obtain the bit pressure through the casing pipe and can also obtain the bit pressure through the mutual matching of the inner drill bit limit and the outer drill bit limit;

5. the design of the pressure bearing and the pilot bearing in the mechanism can realize the function of independent rotation of the outer drill bit and a sleeve above the outer drill bit, the drill bit structure adopted by the inner drill bit can effectively avoid the problem of local false circulation of slurry existing in a high matrix drill bit, the slurry circulation path is limited, the slurry can smoothly reach the bottom of a hole, and the outer drill bit is matched to realize slurry circulation so as to finish the cooling of the drill bit and the cleaning of rock debris at the bottom of the hole;

6. based on the design, the drilling tool system can realize continuous casing drilling in deep broken stratums, effectively solves the problems of drill sticking, buried drilling, hole collapse and the like caused by deep stratum breaking, obviously reduces energy loss, shortens drilling time and improves drilling efficiency.

Drawings

FIG. 1 is an overall cross-sectional view of the present invention.

Fig. 2 is a perspective view of the inner drill bit of the present invention.

Fig. 3 is a perspective view of an outer drill bit of the present invention.

Fig. 4 is a perspective view of the internal bit stop of the present invention.

Fig. 5 is a perspective view of the outer bit stop of the present invention.

FIG. 6 is a perspective cross-sectional view of an outer bit sub of the present invention.

Fig. 7 is a perspective cross-sectional view of a casing joint of the present invention.

Fig. 8 is an overall view of the sleeve and the sleeve joint of the present invention.

Fig. 9 is a schematic view of the pressure transmitting and torque isolating principle of the present invention.

FIG. 10 is a schematic view of the mud circulation trajectory of the present invention.

Fig. 11 is a schematic view of the inner and outer bit nozzle alignment principle of the present invention.

Detailed Description

Referring to fig. 1 to 11, a continuous casing drilling system with double diamond-impregnated bits comprises an inner bit 1, an outer bit 2, a first transmission key 3, a second transmission key 4, an inner bit limit 5, an outer bit limit 6, a first copper sleeve 7, a second copper sleeve 8, an outer bit joint 9, an inner bit joint 10, an elastic sheet 11, an inner sealing element 12, an outer sealing element 13, a lower pressure bearing 14, a middle pressure bearing 15, an upper pressure bearing 16, a lower pilot bearing limit 17, an upper pilot bearing limit 18, a pilot bearing 19, an outer bit joint limit 20, a drill rod 21, a casing joint 22 and a casing 23; n is specified in 4;

the upper end of an inner drill bit 1 is fixedly connected with the lower end of an inner drill bit joint 10 through threads, the upper end of the inner drill bit joint 10 is fixedly connected with the lower end of a drill rod 21 through threads, 4 first key grooves 101 are circumferentially and uniformly distributed on the outer side of the inner drill bit 1, 4 second key grooves 501 are circumferentially and uniformly distributed on the inner side of an inner drill bit limit 5, and a first transmission key 3 is fixed between the first key grooves 101 and the second key grooves 501;

4 third key grooves 201 are circumferentially and uniformly distributed on the inner side of the outer drill bit 2, 4 fourth key grooves 601 are circumferentially and uniformly distributed on the outer side of the outer drill bit limiting 6, and the second transmission key 4 is fixed between the third key grooves 201 and the fourth key grooves 601;

the outer side of the inner bit limit 5 is circumferentially and uniformly provided with 4 first lugs 502, the inner side of the outer bit limit 6 is circumferentially and uniformly provided with 4 second lugs 602, the bottom of the inner side of the outer bit limit 6 is provided with a first boss 603, the inner bit limit 5 and the outer bit limit 6 are coaxially and rotatably connected, the first lug 502 is limited at the upper end of the first boss 603, and when the inner bit limit 5 rotates, the first lug 502 is in abutting engagement with the second lug 602 to realize that the inner bit limit 5 rotates and further drive the outer bit limit 6 to circumferentially rotate;

outer drill bit connects 9 lower extreme and outer drill bit 2 upper ends to pass through screw thread fixed connection, and the annular equipartition has the several to run through to the inside mud hole 901 of outer drill bit connects 9 on the outer drill bit connects 9, still is provided with first hickey 902, first recess 903 and second recess 904 on the outer drill bit connects 9, and 7 outer walls of first copper sheathing pass through screw thread fixed connection with first hickey 902, and shell fragment 11 sets up in second recess 904, and its effect lies in: the lower pressure bearing 14 can better bear pressure, the inner sealing element 12 is arranged in the first groove 903, the lower end of the limit 20 of the outer drill bit joint is fixedly connected with the upper end of the outer drill bit joint 9 through threads, the inner drill bit joint 10 is fixedly connected with the second copper sleeve 8 through threads, the second copper sleeve 8 is limited at the upper end of the first copper sleeve 7, the first copper sleeve 7 and the second copper sleeve 8 can coaxially rotate, the mechanical sealing structure is similar to a mechanical sealing structure, the mechanical sealing structure is mainly used for sealing an annular space gap between the outer drill bit joint 9 and the inner drill bit joint 10, the inner diameter of the first copper sleeve 7 is smaller than the outer diameter of the second copper sleeve 8, and further the axial vertical downward translational motion of the second copper sleeve 8 is limited by the first copper sleeve 7;

the lower end of the sleeve 23 is fixedly connected with the upper end of the sleeve joint 22 through threads, the sleeve joint 22 is provided with a third groove 221 and a fourth groove 222, a lower guide bearing limit 17 and an upper guide bearing limit 18 are fixedly connected with the sleeve joint 22 through threads, the upper end and the lower end of the inner ring of the guide bearing 19 are respectively pressed on the upper end surface of the lower guide bearing limit 17 and the lower end surface of the upper guide bearing limit 18, the outer ring of the guide bearing 19 is fixedly connected with the inner wall of the outer bit joint 9, the upper surface of the lower bearing 14 is tightly connected with the lower end surface of the lower guide bearing limit 17, the lower surface of the lower bearing 14 is tightly contacted with the upper end surface of the elastic sheet 11, the upper end of the inner sealing element 12 is tightly contacted with the lower end surface of the sleeve joint 22, the lower surface of the middle bearing 15 is tightly contacted with the upper surface of the upper guide bearing limit 18, the upper surface of the middle bearing 15 is tightly contacted with the lower surface of the inner side of the outer bit joint limit 20, the upper bearing 16 is arranged in the third groove 221, and the lower surface of the upper pressure bearing 16 is in close contact with the upper surface of the outer side of the outer bit joint limit 20, the outer sealing element 13 is installed in the fourth groove 222, and the outer sealing element 13 is in close contact with the upper surface of the outer side of the outer bit joint limit 20.

Further, referring to fig. 8, the outer surface of the sleeve 23 and the sleeve joint 22 is provided with a characteristic spiral groove structure 24; the function is as follows: in actual drilling, if the casing 23 becomes stuck by broken rock, the casing 23 may be driven by surface equipment so that the casing 23 is rotationally stuck free in its turn by virtue of the characteristic helical groove structure of its surface.

Furthermore, the inner diameter of the first copper sleeve 7 is smaller than the outer diameter of the second copper sleeve 8, the inner diameter of the first copper sleeve 7 is larger than the outer diameter of the first transmission key 3, and the inner diameter of the first copper sleeve 7 is larger than the outer diameter of the first bump 502, so that the axial vertical downward translational movement of the second copper sleeve 8 is limited by the first copper sleeve 7.

Further, referring to fig. 2, 3, 10 and 11, the mechanism uses a specific high matrix bit designed independently by the subject group for both the inner bit and outer bit working layer structure. The specific structural design of the working layer of the inner drill bit 1 can refer to the patent of 'ultrahigh working layer involute water gap diamond-impregnated bit and preparation method thereof', and the patent application number is CN 202111097075.2; the specific structural design of the working layer of the outer drill bit 2 can refer to the patent "integral cutting tooth diamond-impregnated drill bit", with the patent application number of CN 201910991035.9. The steel body structure of inside and outside drill bit is different with the impregnated diamond drill bit of conventionality, changes the specific structure of drilling tool system design for the cooperation, and the high matrix design of interior drill bit and outer drill bit can increase the drilling depth, and then increases the pipe-following degree of depth, can realize creeping into with the sleeve pipe in succession, until reaching the life-span of drill bit. In actual drilling, the carcass height design of the inner drill bit and the outer drill bit is determined according to actual drilling requirements. The structural design of the inner drill bit 1 can effectively avoid the occurrence of the local pseudo-circulation phenomenon of the slurry existing in the high matrix drill bit, and meanwhile, the inner drill bit 1 limits the flow path of the slurry, so that the slurry can be sufficiently circulated at the outer drill bit 2. Based on the design, no matter how high the inner drill bit and the outer drill bit matrix are, the slurry can be conveyed to the bottom of the drill hole firstly, and the effects of cooling the drill bit and cleaning rock debris at the bottom of the drill hole are achieved. The inner drill bit and the outer drill bit are matched with each other, so that continuous casing drilling can be realized, the drilling is not stopped halfway until the service life of the drill bit or the drilling design requirement is met, the drilling time can be greatly shortened, the drilling cost is saved, and the energy loss in the drilling process is reduced. The drilling efficiency is improved.

Further, referring to fig. 4, 5 and 11, the maximum outer diameter of the inner bit limit 5 is larger than the minimum inner diameter of the outer bit limit 6. In actual movement, the first lug 502 arranged outside the inner bit limit 5 is blocked by the first boss 603 arranged inside the outer bit limit 6, so that the axial vertical downward translation movement of the inner bit limit is limited; meanwhile, the first bump 501 arranged on the outer side of the inner bit limit 5 is blocked by the second bump 602 arranged on the inner side of the outer bit limit 6, so that the circumferential rotary motion of the inner bit limit 5 is limited, and the inner bit limit 5 can only rotate within a certain angle range; as shown in fig. 11, the inner bit gate 102 of the inner bit 1 is in aligned relation with the outer bit gate 202 of the outer bit 2 when the first projection 502 outside the inner bit stop 5 contacts the second projection 602 inside the outer bit stop 6. At this time, the rotation of the inner drill bit 1 drives the rotation of the outer drill bit 2.

Further, referring to fig. 9, in the region between the outer bit joint 9 and the casing joint 22, there are provided an elastic sheet 11, an inner sealing member 12, an outer sealing member 13, a lower pressure bearing 14, a middle pressure bearing 15, an upper pressure bearing 16, a pilot bearing 19, a lower pilot bearing limit 17, and an upper pilot bearing limit 18. Based on the above design, the outer bit joints 9 located in the third area are subjected to the pressure P exerted by the casing joints 22 and the casing 23 located in the first area. However, the casing joint 22 and the casing 23 located in the region (c) are not subjected to the torque generated by the rotation of the outer bit joint 9 located in the region (c). I.e. the outer drill bit 2 is independent from the casing 23, the casing 23 only provides drilling pressure for the outer drill bit 2, the outer drill bit 2 only performs rotary drilling and is not able to apply a rotary torque to the casing 23. When the special condition that the sleeve 23 is blocked by broken rocks occurs, the sleeve 23 can be driven to rotate by ground equipment to play a role in releasing the blockage under the condition that the normal drilling of the outer drill bit 2 is not influenced.

Further, in conjunction with fig. 2, 3, 10 and 11, it can be seen that the mud circulation is divided into two paths:

the first case is: the mud flows out of the inner drill bit 1, flows through the inner drill bit water gap 102 and the outer drill bit water gap 202 at the bottom of the outer drill bit 2, enters an annular space formed by the outer drill bit 2 and the hole wall, finally passes through a mud hole 901 on the outer drill bit joint 9 and enters an annular space gap formed by the drill rod 21 and the sleeve 23, and the whole circulation is completed;

the second case is: because the outer drill bit water gap 202 of the outer drill bit 2 has multiple layers, a part of slurry flows out from the inner drill bit 1, flows through the inner drill bit water gap 102 and the water gap 202 at the bottom of the outer drill bit 2, enters an annular space formed by the outer drill bit 2 and a hole wall, and finally enters an annular space gap formed by the drill rod 21 and the casing 23 through a slurry hole 901 on the outer drill bit joint 9;

the rest part flows out from the inner drill bit 1, passes through the inner drill bit water gap 102, enters an annular space formed by the inner drill bit 1 and the outer drill bit 2, flows out through the outer drill bit water gap (202) at the upper part of the outer drill bit 2, enters an annular space formed by the outer drill bit 2 and the hole wall, finally enters an annular space gap formed by the drill rod 21 and the sleeve 23 through a mud hole 901 on the outer drill bit joint 9, and the whole circulation is completed.

The working principle of the invention is as follows:

the invention relates to a continuous casing drilling tool system with double diamond-impregnated bits, wherein the working layer structures of an inner bit and an outer bit are both special high matrix bits independently designed by a subject group, the steel body part is newly designed to meet the structural requirements of the drilling tool system, the inner bit 1 is driven to rotate by a drill rod 21, the outer bit 2 is driven to rotate by the inner bit 1 through a first transmission key 3 and a second transmission key 4, the inner bit 1 provides drilling pressure through the drill rod 21, and the outer bit 2 provides drilling pressure through a casing 23 and the drill rod 21. The design of the pressure bearing and the pilot bearing in the mechanism can realize the function that the outer drill bit 2 and the sleeve 23 above the outer drill bit rotate independently. The problem of the false circulation of local mud that high matrix drill bit exists can effectively be avoided to the drill bit structure of interior drill bit 1 adoption, and restriction mud circulation route makes mud can reach the bottom of a hole, and outer drill bit 2 of deuterogamying realizes the mud circulation, accomplishes the clearance to the cooling of drill bit and bottom of a hole detritus. In the actual drilling process, the inner drill bit and the outer drill bit are small in disturbance to the well wall by the diamond-impregnated drill bit, the hole wall is relatively regular, the drilling depth can be greatly improved by matching with a high matrix design, the pipe following depth is further increased, and continuous pipe following drilling is realized until the service life of the drill bit or the drilling design requirement is met. Meanwhile, as the drilling is not stopped in the drilling process, the sleeve can independently rotate and continuously follow up, and the friction between the sleeve and the hole wall is always expressed as dynamic friction, compared with the static friction generated when the drilling is stopped, the energy loss can be obviously reduced, the drilling time is shortened, and the drilling efficiency is improved.

Claims (5)

1. The utility model provides a two pregnant diamond-impregnated bit are with casing drilling tool system in succession which characterized in that: the drill bit comprises an inner drill bit (1), an outer drill bit (2), a first transmission key (3), a second transmission key (4), an inner drill bit limit (5), an outer drill bit limit (6), a first copper sleeve (7), a second copper sleeve (8), an outer drill bit joint (9), an inner drill bit joint (10), an elastic sheet (11), an inner sealing element (12), an outer sealing element (13), a lower pressure bearing (14), a middle pressure bearing (15), an upper pressure bearing (16), a lower pilot bearing limit (17), an upper pilot bearing limit (18), a pilot bearing (19), an outer drill bit joint limit (20), a drill rod (21), a casing joint (22) and a casing (23);

the upper end of an inner drill bit (1) is fixedly connected with the lower end of an inner drill bit joint (10), the upper end of the inner drill bit joint (10) is fixedly connected with the lower end of a drill rod (21), N first key grooves (101) are circumferentially and uniformly distributed on the outer side of the inner drill bit (1), N is larger than or equal to 1, N second key grooves (501) are circumferentially and uniformly distributed on the inner side of an inner drill bit limit (5), N is larger than or equal to 1, N first transmission keys (3) are fixed between the first key grooves (101) and the second key grooves (501), and N is larger than or equal to 1;

n third key grooves (201) are circumferentially and uniformly distributed on the inner side of the outer drill bit (2), N is larger than or equal to 1, N fourth key grooves (601) are circumferentially and uniformly distributed on the outer side of the outer drill bit limiting block (6), N is larger than or equal to 1, and N second transmission keys (4) are fixed between the third key grooves (201) and the fourth key grooves (601);

n first lugs (502) are circumferentially and uniformly distributed on the outer side of the inner drill bit limit (5), N is larger than or equal to 1, N second lugs (602) are circumferentially and uniformly distributed on the inner side of the outer drill bit limit (6), N is larger than or equal to 1, a first boss (603) is arranged at the bottom of the inner side of the outer drill bit limit (6), the inner drill bit limit (5) and the outer drill bit limit (6) are coaxially and rotatably connected, the first lugs (502) are limited at the upper ends of the first bosses (603), and when the inner drill bit limit (5) rotates, the first lugs (502) are in abutting engagement with the second lugs (602), so that the inner drill bit limit (5) rotates to drive the outer drill bit limit (6) to rotate circumferentially;

the lower end of an outer drill bit joint (9) is fixedly connected with the upper end of an outer drill bit (2), a plurality of slurry holes (901) penetrating into the outer drill bit joint (9) are uniformly distributed on the outer drill bit joint (9) in the circumferential direction, a first threaded connector (902), a first groove (903) and a second groove (904) are further arranged on the outer drill bit joint (9), the outer wall of a first copper sleeve (7) is fixedly connected with the first threaded connector (902) through threads, an elastic sheet (11) is arranged in the second groove (904), an inner sealing element (12) is arranged in the first groove (903), the lower end of an outer drill bit joint limit (20) is fixedly connected with the upper end of the outer drill bit joint (9), an inner drill bit joint (10) is fixedly connected with a second copper sleeve (8), the second copper sleeve (8) is limited at the upper end of the first copper sleeve (7), the first copper sleeve (7) and the second copper sleeve (8) can coaxially rotate, and further the annular gap between the outer drill bit joint (9) and the inner drill bit joint (10) is sealed, the inner diameter of the first copper sleeve (7) is smaller than the outer diameter of the second copper sleeve (8);

the lower end of a sleeve (23) is fixedly connected with the upper end of a sleeve joint (22), the sleeve joint (22) is provided with a third groove (221) and a fourth groove (222), a lower guide bearing limit (17) and an upper guide bearing limit (18) are fixedly connected with the sleeve joint (22), the upper end and the lower end of an inner ring of a guide bearing (19) are respectively pressed on the upper end surface of the lower guide bearing limit (17) and the lower end surface of the upper guide bearing limit (18), an outer ring of the guide bearing (19) is fixedly connected with the inner wall of an outer drill bit joint (9), the lower end surface of the lower guide bearing limit (17) on the upper surface of a lower pressure bearing (14) is tightly connected, the lower surface of a lower pressure bearing (14) is tightly contacted with the upper end surface of an elastic sheet (11), the upper end of an inner sealing element (12) is tightly contacted with the lower end surface of the sleeve joint (22), the lower surface of a middle pressure bearing (15) is tightly contacted with the upper surface of the upper guide bearing limit (18), the upper surface of the middle pressure bearing (15) is in close contact with the lower surface of the inner side of the outer bit joint limit (20), the upper pressure bearing (16) is installed in the third groove (221), the lower surface of the upper pressure bearing (16) is in close contact with the upper surface of the outer side of the outer bit joint limit (20), the outer sealing element (13) is installed in the fourth groove (222), and the outer sealing element (13) is in close contact with the upper surface of the outer side of the outer bit joint limit (20).

2. The dual-impregnated diamond-impregnated drill bit continuous-tracking casing drilling system according to claim 1, wherein: when the sleeve (23) is clamped by broken rocks, the sleeve (23) is driven by ground equipment, so that the sleeve (23) is rotationally unlocked by the characteristic spiral groove structure (24) on the surface of the sleeve (23) in rotation.

3. The dual-impregnated diamond-impregnated drill bit continuous-tracking casing drilling system according to claim 1, wherein: when the first lug (502) on the outer side of the inner drill bit limit (5) is contacted with the second lug (602) on the inner side of the outer drill bit limit (6), the inner drill bit water gap (102) of the inner drill bit (1) is aligned with the outer drill bit water gap (202) of the outer drill bit (2).

4. The dual-impregnated diamond bit continuous-tracking casing drilling system according to any one of claims 1 to 3, wherein: the inner drill bit (1) is an ultrahigh working layer involute water gap diamond-impregnated drill bit.

5. The dual-impregnated diamond bit continuous-tracking casing drilling system according to any one of claims 1 to 3, wherein: the outer drill bit (2) is an integrated cutting tooth diamond-impregnated drill bit.

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