CN-115949341-B - Underground rotary directional drilling tool assembly for coal mine and drilling method

CN115949341BCN 115949341 BCN115949341 BCN 115949341BCN-115949341-B

Abstract

The invention discloses a coal mine underground rotary directional drilling tool assembly and a drilling method, wherein the coal mine underground rotary directional drilling tool assembly comprises a central cable drill rod, a communication conversion nipple, a drilling mode switching nipple, a support stabilization nipple, a screw drilling tool and a drill bit which are sequentially connected from back to front; the rotary directional drilling tool assembly and the drilling method have the remarkable advantages of low bending strength of drilling tracks, high drilling power transmission efficiency, good drilling slag discharging effect and the like, greatly improve the service life of the drilling tool, the drilling depth and the drilling safety, and powerfully ensure the safe and efficient construction of underground directional long drilling of the coal mine.

Inventors

LI QUANXIN
CHU ZHIWEI
HAO SHIJUN
FANG JUN
LIU JIANLIN
CHEN LONG
LIU ZHI
LIU FEI

Assignees

中煤科工西安研究院(集团)有限公司

Dates

Publication Date: 20260508
Application Date: 20230103

Claims (6)

1. The underground coal mine rotary directional drilling tool assembly is characterized by comprising a central cable drill rod (1), a communication conversion nipple (2), a drilling mode switching nipple (3), a support stabilizing nipple (4), a screw drilling tool (5) and a drill bit (6) which are sequentially connected from back to front, wherein the communication conversion nipple (2) comprises a communication conversion nipple body (201), a central cable (202) and a magnetic coupling communication joint a (203) are sequentially arranged in the communication conversion nipple body (201) from back to front, the central cable (202) and the magnetic coupling communication joint a (203) are respectively connected with the central cable drill rod (1) and the drilling mode switching nipple (3), and two fixed support rings (204) are arranged at two ends of the support central cable (202); The drilling mode switching nipple (3) is provided with a drilling mode switching nipple body (301), one end of the drilling mode switching nipple body (301) is fixedly connected with the communication switching nipple (2) through threads, the other end of the drilling mode switching nipple body is movably connected with the support stabilizing nipple (4) and can realize circumferential rotary motion, a drilling mode switching center rod (303) is arranged in a center channel of the drilling mode switching nipple body (301), and a limiting ring a (302), a drilling mode switching chuck (3010), a spring a (309) and a spring fixing ring a (308) are sequentially arranged on the inner wall of the drilling mode switching nipple body (301) from back to front; 4 sliding clamping grooves (3011) are formed in the inner wall of the body (301) at equal angles in the circumferential direction, 4 sliding convex keys (30101) are formed in the outer wall of the drilling mode switching chuck (3010) at equal angles in the circumferential direction, and the drilling mode switching chuck (3010) can axially move along the sliding clamping grooves (3011) by utilizing the 4 sliding convex keys (30101); 4 limit screw holes (3012) are formed in the outer wall of the body (301) at equal angles in the circumferential direction, a plurality of locking convex keys (30102) are formed in the front end face of the drilling mode switching chuck (3010) at equal angles and are matched with corresponding locking grooves (3031) formed in the outer wall of the rear end of the drilling mode switching center rod (303); The drilling mode switching center rod (303) is provided with a locking groove (3031), a water passing hole a (3032), a rotary dynamic seal mounting groove (3035), a wear-resistant bearing mounting groove (3033) and a limit screw mounting groove (3034) from back to front in sequence, the rotary dynamic seal mounting groove (3035) is provided with a rotary dynamic seal (304), the wear-resistant bearing mounting groove (3033) is internally provided with a wear-resistant bearing (306), the limit screw mounting groove (3034) is internally provided with a limit screw (305), the water passing hole a (3032) is communicated with the inside of the drilling mode switching center rod (303) and the center channel of the body (301), the inside of the drilling mode switching center rod (303) is provided with a inclinometry component (307), the inclinometry component (307) comprises a magnetic coupling communication joint b (307) and a fixed ring (3072), a rubber centralizer (3073) and an inclinometry unit (3074), and the magnetic coupling communication joint b (3071) is connected to the axial rear end of the inclinometry unit (3074); The support stabilization nipple (4) is provided with a support stabilization nipple body (401), a plurality of water passing holes b (4011) are equiangularly formed in the side wall of the front end of the support stabilization nipple body (401), the water passing holes b (4011) are communicated with the inside of the support stabilization nipple body (401) and the inside of a screw drilling tool (5), the circumferential direction of the outer wall of the support stabilization nipple body (401) is provided with 3 pushing leg mounting grooves (4012) at equal angles, and a piston assembly limiting ring (406), a piston assembly (405), a spring b (404) and a spring fixing ring b (403) are sequentially arranged in a central channel of the support stabilization nipple body (401); 4 water through holes b (4011) are formed in the side wall of the front end of the support stable nipple body (401) at equal angles; 4 water holes are uniformly distributed on the piston assembly limiting ring (406).
2. The downhole rotational orientation drilling assembly of claim 1, wherein the springs a (309) are circumferentially equispaced 4.
3. A method of coal mine downhole rotary directional drilling, the method utilizing the coal mine downhole rotary directional drilling assembly of claim 1 or 2 for drilling construction, comprising the steps of: the method comprises the steps of (1) measuring drilling track parameters, namely, putting the coal mine underground rotary directional drilling tool assembly into a drill hole, sequentially arranging a drill bit (6), a screw drilling tool (5), a support stabilizing nipple (4), a drilling mode switching nipple (3), a communication switching nipple (2), a plurality of center cable drilling rods (1) and a water feeder from the bottom of the drill hole to an orifice, measuring current drilling track parameter information by using a inclinometer unit (3074) in the drilling mode switching nipple (3), and transmitting the drilling track parameter information to the communication switching nipple (2) in a wireless communication mode through a magnetic coupling communication joint b (3071) and a magnetic coupling communication joint a (203), wherein a center cable (202) of the communication switching nipple (2) transmits the drilling track parameter information to the orifice in a wired communication mode through a plurality of center cable drilling rods (1); (2) The method comprises the steps of adjusting the facing angle of a screw drilling tool, namely, calculating the facing angle of the tool required to be adjusted by an orifice monitoring terminal according to the measured drilling inclination angle, azimuth angle parameter information and the facing angle of the screw drilling tool, inputting high-pressure flushing fluid into a coal mine underground rotary directional drilling tool assembly by a slurry pump through a water feeder, setting flushing fluid displacement to push a leaning leg (402) out of a supporting drilling hole wall by the flushing fluid, overcoming the resistance of a spring a (309) by flushing fluid pressure, pushing a locking convex key (30102) on the front end surface of a drilling mode switching chuck (3010) into a locking groove (3031) on the rear end of a drilling mode switching center rod (303), and realizing the locking of the drilling mode switching center rod (303) on the circumferential drilling of a drilling mode switching nipple body (301), so as to realize the joint rotation of a communication switching nipple (3) and a supporting stable nipple (4), and driving a communication switching nipple (2), the drilling mode switching nipple (3), the supporting stable nipple (4) and the whole screw drilling tool (5) to rotate together by using a drilling machine rotary center cable drilling rod (1) to drive the rotary angle of the screw drilling tool required to be adjusted according to the calculation of the rotating angle of the screw drilling tool (5; (3) And (3) rotary directional drilling, namely reducing flushing fluid displacement, enabling a pushing leg (402) in a supporting stable nipple (4) to still support a hole wall to prevent a screw drilling tool (5) from rotating so as to keep a tool facing angle stable, enabling a drilling mode switching chuck (3010) in a drilling mode switching nipple (3) to be separated from a locking groove (3031) by insufficient flushing fluid displacement, enabling the drilling mode switching nipple (301) to rotate relative to a drilling mode switching center rod (303), driving the communication switching nipple (2) and the drilling mode switching nipple (3) to integrally rotate by utilizing a drilling machine rotation center cable drill rod (1), supporting the stable nipple (4) and the screw drilling tool (5) not to rotate, and realizing rotary directional drilling by utilizing drilling machine construction.
4. A method of downhole rotary steerable drilling in a coal mine as claimed in claim 3, wherein in step (2) the flushing fluid displacement is set to be above 350L/min.
5. A method of downhole rotary steerable drilling in a coal mine as claimed in claim 3, wherein in step (3) the flushing fluid displacement is reduced to 300L/min.
6. The method of coal mine downhole rotary directional drilling according to claim 3, wherein in the step (2), the lower rotation speed is 10-20 r/min.

Description

Underground rotary directional drilling tool assembly for coal mine and drilling method Technical Field The invention belongs to the field of underground coal mine tunnel drilling, and particularly relates to an underground coal mine rotary directional drilling tool assembly and a drilling method. Background The directional drilling technology for underground measurement while drilling of the coal mine has the remarkable advantages of good track controllability, large drilling depth, high pore-forming efficiency and the like, and is widely applied to the fields of regional gas extraction, rock burst prevention and control, advanced geological exploration and the like, and the safe and efficient production of the coal mine is effectively ensured. At present, a sliding directional drilling tool assembly and a drilling method are mainly adopted for constructing directional drilling in the underground coal mine, a drill rod, a non-magnetic drill rod and a screw drill are not integrally rotated in the drilling process, and only a rotor in the screw drill drives a drill bit to rotate so as to break the coal stratum to form holes. Thus, the screw drill elbow joint can maintain a specific direction (the tool face angle remains stable), and directional drilling is achieved in a sliding manner by pushing the in-hole drill with the drill feed force. However, the following problems exist in constructing directional drilling using existing sliding directional drilling tool assemblies and drilling methods: (1) The bending strength of the drilled holes is high, the drilling tool is stressed in a complex manner. The existing sliding directional drilling tool assembly and drilling method (refer to China patent application CN 201810728314.1) are poor in smoothness of the wall of a drilling hole, high in bending strength of drilling tracks after continuous deflecting, high in stress strength and complex in stress mode of the drilling tool assembly in the hole, and the service life of the drilling tool assembly is reduced. (2) The sliding drilling friction is large, and the pore-forming depth is limited. The existing sliding directional drilling tool assembly and the drilling method can only cut the coal stratum laterally under the sliding state to perform directional drilling, most of the drilling feeding force is used for counteracting sliding friction resistance between a drill string and a hole wall, only a small part of the feeding force acts on the screw drilling tool, the drilling feeding force is insufficient, the hole forming capability is greatly limited, and the hole forming depth is severely limited. (3) The drilling sediment is more, and the drilling safety is low. The existing sliding directional drilling mode relies on high-pressure flushing liquid to remove slag, the slag removing capability is insufficient, drilling slag is easy to accumulate at the bottom of a hole in a large quantity, particularly when drilling is carried out on complex broken coal strata, the slag removing problem is outstanding, complex working conditions in holes such as slag depositing, collapse Kong Kazuan and the like are easy to occur, and the drilling safety is obviously reduced. Therefore, the designer of the invention has the defects that the experience and achievement of related industries are integrated through intensive research and design, and the coal mine underground rotary directional drilling tool combination and the drilling method are researched and designed to overcome the defects aiming at the problems of complex drilling tool stress, limited hole forming depth and low drilling safety of the traditional sliding directional drilling tool combination and the drilling method. Disclosure of Invention The invention aims to provide a coal mine underground rotary directional drilling tool assembly and a drilling method, which aim at solving the problems of complex drilling tool stress, limited hole forming depth and low drilling safety of the traditional sliding directional drilling tool assembly and the drilling method. In order to achieve the above purpose, the present invention provides the following technical solutions: On one hand, the invention provides a coal mine underground rotary directional drilling tool assembly, which comprises a central cable drill rod, a communication conversion nipple, a drilling mode switching nipple, a support stabilization nipple, a screw drilling tool and a drill bit which are sequentially connected from back to front, wherein the communication conversion nipple comprises a communication conversion nipple body, a central cable and a magnetic coupling communication connector are sequentially arranged in the communication conversion nipple body from back to front, and the central cable and the magnetic coupling communication connector a are respectively connected with the central cable drill rod and the drilling mode switching nipple; The drilling mode switching nipple is characterized in tha