CN113719237B - Drilling tool assembly and method for directional long drilling construction of gas extraction of crushed soft and thin coal seam - Google Patents
Drilling tool assembly and method for directional long drilling construction of gas extraction of crushed soft and thin coal seam Download PDFInfo
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- CN113719237B CN113719237B CN202110968895.8A CN202110968895A CN113719237B CN 113719237 B CN113719237 B CN 113719237B CN 202110968895 A CN202110968895 A CN 202110968895A CN 113719237 B CN113719237 B CN 113719237B
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- 238000005553 drilling Methods 0.000 title claims abstract description 168
- 239000003245 coal Substances 0.000 title claims abstract description 68
- 238000000605 extraction Methods 0.000 title claims abstract description 26
- 238000010276 construction Methods 0.000 title claims abstract description 25
- 238000000034 method Methods 0.000 title claims abstract description 18
- 210000002445 nipple Anatomy 0.000 claims abstract description 129
- 238000004891 communication Methods 0.000 claims abstract description 120
- 238000005259 measurement Methods 0.000 claims abstract description 81
- 239000011435 rock Substances 0.000 claims abstract description 15
- 230000002285 radioactive effect Effects 0.000 claims abstract description 11
- 230000005251 gamma ray Effects 0.000 claims abstract description 7
- 230000005540 biological transmission Effects 0.000 claims description 49
- 238000013461 design Methods 0.000 claims description 16
- 230000008054 signal transmission Effects 0.000 claims description 8
- 230000015572 biosynthetic process Effects 0.000 claims description 7
- 230000000087 stabilizing effect Effects 0.000 claims description 7
- 238000013459 approach Methods 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 claims description 3
- 238000010073 coating (rubber) Methods 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- 238000012937 correction Methods 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 238000012545 processing Methods 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 4
- 230000000712 assembly Effects 0.000 description 3
- 238000000429 assembly Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011010 flushing procedure Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000009991 scouring Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000005641 tunneling Effects 0.000 description 1
Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F7/00—Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose
Abstract
The application discloses a drilling tool assembly and a drilling method for directional long drilling construction of gas extraction of a crushed soft thin coal seam, wherein the drilling tool assembly comprises a directional drill bit, a front measuring nipple, a non-magnetic wire-passing screw drilling tool, a rear measuring nipple and a central cable drill rod which are connected in sequence; the front measurement nipple is used for measuring the drilling inclination angle at the near-bit position, the tool facing angle and the natural gamma-ray radioactive intensity of the stratum; the nonmagnetic wire-passing screw drilling tool is used for providing rock crushing power for the drill bit, and transmitting the measurement data of the front measurement nipple to the rear measurement nipple through the nonmagnetic wire-passing screw drilling tool side wall communication assembly; the rear measurement nipple is used for receiving measurement data of the front measurement nipple and measuring the azimuth angle of the drilling hole; the central cable drill rod is used for uploading hole bottom measurement data. By adopting the technical scheme of the application, the hole forming depth and the hole forming rate of the gas extraction drilling holes of the crushed soft and thin coal layer can be effectively improved, the gas control period is shortened, and the gas control cost is reduced.
Description
Technical Field
The application belongs to the field of underground coal mine gas extraction, and particularly relates to a drilling tool assembly and a drilling method for directional long drilling construction of broken soft thin coal seam gas extraction.
Background
The thin coal seam is widely distributed in China, mainly refers to the coal seam with the thickness smaller than 1.3m, and accounts for about 20% of the coal resource reserves in China. In order to improve the recovery rate of coal, coal beds with the specified thickness of more than 0.8m in China need to be mined, and coal beds with the thickness of less than 0.8m encourage mining. However, the gas control of the crushed soft thin coal layer becomes a main problem which restricts the safe and efficient exploitation of the crushed soft thin coal layer, and the reason is that the hole depth of the gas extraction drilling hole of the crushed soft thin coal layer is shallow and the hole forming rate is low.
Because the thickness of the crushed soft and thin coal layer is small, fluctuation change is large, the drilling track of the conventional rotary drilling technology is uncontrollable, the top or bottom contact is easy, so that the gas is effectively extracted from the hole Duan Shao, and the parameters such as the drilling inclination angle, the azimuth angle, the tool face and the like which are mainly collected by the current measurement while drilling system are used for guiding the adjustment of the drilling track, and the condition of drilling meeting the stratum is judged simply by virtue of the change condition of returning water of the drilling, so that the accurate judgment of the lithology of the stratum and the coal-rock interface is difficult to realize. Secondly, the measurement while drilling exploratory tube is arranged about 6m away from the drill bit, the drilling track is regulated and controlled with lag, the drill bit is very easy to drill a thin coal seam, the operation of branching holes is difficult, and the accurate extension of the drilling track along the thin coal seam is difficult to ensure. In addition, the underground directional drilling technology adopts clear water as flushing fluid, has larger flushing disturbance on the wall of the broken soft thin coal seam, causes frequent hole collapse and orifice spraying accidents, and is difficult to adapt to the long-distance hole forming requirement of the broken soft thin coal seam.
Disclosure of Invention
Aiming at the defects and shortcomings in the prior art, the application provides the drilling tool assembly and the drilling method for the gas extraction directional long drilling construction of the crushed soft thin coal layer, which overcome the technical defects and the problems of the conventional directional drilling tool assembly in the gas extraction drilling construction of the crushed soft thin coal layer, realize the accurate extension of the gas extraction drilling track along the long distance of the thin coal layer, simultaneously reduce the probability of hole collapse and hole spraying of the drilling holes, improve the hole forming depth and the hole forming efficiency of the crushed soft thin coal layer, and solve the defect problems in the prior art.
In order to achieve the above purpose, the application adopts the following technical scheme:
a drilling tool assembly for directional long drilling construction of gas extraction of crushed soft and thin coal layers comprises a directional drill bit, a front measuring nipple, a non-magnetic wire-passing screw drilling tool, a rear measuring nipple and a central cable drill rod which are sequentially connected from bottom to top;
the front measurement nipple comprises a transmission central shaft with a central through hole, a front measurement nipple outer tube sleeved outside the transmission central shaft and a communication measurement unit arranged on the front measurement nipple outer tube; the non-magnetic threading screw drilling tool comprises a central power unit, a non-magnetic drilling tool outer pipe sleeved outside the central power unit, a communication cable assembly embedded in the non-magnetic drilling tool outer pipe, a communication nipple outer pipe and a side wall rotary center communication nipple arranged in the communication nipple outer pipe; the rear measurement nipple comprises a central communication measurement unit and a rear measurement nipple outer tube sleeved outside the central communication measurement unit; the center cable drill rod comprises a center cable and a drill rod outer pipe;
the directional drill bit, the transmission central shaft and the central power unit are sequentially connected; the front measuring nipple outer tube, the nonmagnetic drilling tool outer tube, the communication nipple outer tube, the rear measuring nipple outer tube and the drill rod outer tube are connected in sequence; the communication measuring unit, the communication cable assembly, the side wall center-to-center communication nipple, the center communication measuring unit and the center cable are sequentially communicated.
The application also comprises the following technical characteristics:
optionally, the communication measurement unit is used for measuring the near-bit position drilling inclination angle, the tool facing angle and the natural gamma-ray radioactive intensity of the stratum; the system comprises a communication joint, a communication cable, a signal transmission unit, a voltage stabilizing unit, an engineering parameter measuring unit and an azimuth gamma measuring unit which are connected in sequence; the pressure stabilizing unit can supply power to the signal transmission unit, the engineering parameter measurement unit and the azimuth gamma measurement unit, and the communication connector is arranged at the end part of the outer tube of the front measurement nipple and can be communicated with the nonmagnetic wire-passing screw drilling tool.
Optionally, a transmission joint is arranged at the front end of the transmission central shaft so as to be connected with the directional drill bit, and the transmission central shaft can transmit the power output by the nonmagnetic wire-passing screw drilling tool to the directional drill bit; and the inner wall of the outer tube of the front measurement nipple is provided with a wear-resistant rubber coating.
Optionally, the central power unit comprises a transmission shaft, a universal shaft and a screw motor which are sequentially connected; the outer tube of the non-magnetic drilling tool comprises a transmission shaft outer tube sleeved outside the transmission shaft, a universal shaft outer tube sleeved outside the universal shaft and a screw motor outer tube sleeved outside the screw motor, which are sequentially connected.
Optionally, the joint of the outer tube of the front measurement nipple and the outer tube of the transmission shaft, the joint of the outer tube of the transmission shaft and the outer tube of the universal shaft, the joint of the outer tube of the universal shaft and the outer tube of the screw motor, and the joint of the outer tube of the screw motor and the outer tube of the communication nipple are respectively provided with a cross-joint communication assembly so as to form a wired communication transmission channel among the communication measurement unit, the communication cable assembly and the side wall rotary center communication nipple;
optionally, the crossover communication assembly includes two opposite insulating rubber rings, an annular groove I is provided on the insulating rubber ring I, and an annular groove II is provided on the insulating rubber ring II; the annular groove I is internally provided with a male slip ring, a high-strength spring is arranged between the male slip ring and the bottom of the annular groove I, and the annular groove II is internally provided with a female slip ring; the male slip ring and the female slip ring are in matched contact, and the male slip ring and the female slip ring are respectively connected with a jumper cable which extends out of the two insulating rubber rings.
Optionally, the screw motor comprises a stator arranged on the inner wall of the outer tube of the screw motor and a rotor arranged in the stator.
Optionally, the communication cable assembly comprises a communication cable, and further comprises a wear-resistant rubber covering layer, a protective metal tube and a wear-resistant alloy coating which are sequentially coated outside the communication cable from inside to outside.
Optionally, the central communication measuring unit of the rear measuring nipple comprises a signal receiving unit, an azimuth measuring unit and a signal transmitting unit which are sequentially connected; the azimuth measuring unit can measure the azimuth of a drilling hole, the signal receiving unit is connected with the side wall-to-center communication nipple and can supply power to the side wall-to-center communication nipple, the signal receiving unit can also receive near-bit measuring information transmitted by the front-end measuring nipple, and the signal transmitting unit transmits measuring data in the hole to the hole opening through the center cable drill rod; the rear measurement nipple is powered by an orifice explosion-proof computer;
a centralizer is arranged between the signal receiving unit and the outer tube of the rear measuring nipple, and a fixing ring is arranged between the signal transmitting unit and the outer tube of the rear measuring nipple; the fixed ring is used for fixing the central communication measuring unit, and the centralizer is used for centralizing the central communication measuring unit.
The construction method for directional long drilling of the gas extraction of the crushed soft thin coal seam is characterized by being realized through the construction drilling tool assembly; the method comprises the following steps:
step one: drilling trajectory parameters and formation natural gamma-ray radioactivity intensity measurements: in the drilling process, measuring the inclination angle of a near-bit position hole Duan Zuankong and the facing angle of a tool by using an engineering parameter measuring unit in a front measuring nipple to obtain the change condition of a drilling track in the vertical direction; carrying out natural gamma radioactive intensity measurement on stratum near the bit position by using an azimuth gamma measurement unit in the front measurement nipple; the natural radioactivity intensity of the stratum above the azimuth gamma measuring unit is represented by an upper gamma value, the natural radioactivity intensity of the stratum below the azimuth gamma measuring unit is represented by a lower gamma value, the azimuth angle of the drilling hole is measured by a rear measuring nipple azimuth measuring unit, and the change condition of the drilling hole track in the horizontal direction is obtained;
step two: and (3) measuring data real-time transmission: the data such as the inclination angle, azimuth angle, tool facing angle and natural gamma radioactive intensity of the stratum of the drilling are encoded by utilizing a rear measurement nipple signal transmitting unit, and are uploaded to an orifice explosion-proof computer through a central cable drill rod;
step three: and (3) measurement data processing: identifying formation lithology and coal stratum interfaces by using the acquired natural gamma radioactivity intensity of the stratum, accurately positioning the drill bit position by combining the acquired inclination angle, azimuth angle and relation with the hole depth of the drill bit, determining the vertical distance between the drill bit and the coal stratum interfaces, predicting the included angle between the extending direction of the drill bit and the coal stratum interfaces, inverting the spatial spread of the rock stratum on the top and bottom plates and the thickness change characteristics of the thin coal stratum, updating an initial three-dimensional geological model, and establishing a three-dimensional dynamic geological model; real-time correction is carried out on the drilling design track based on the three-dimensional dynamic geological model, and the design track is adjusted to extend along the actually detected thin coal seam; and controlling the nonmagnetic line-passing screw drilling tool to conduct guide drilling according to the corrected design track until the design hole depth is reached.
In the drilling process, when the gamma value under the stratum measured by the front measurement nipple is increased firstly and then the gamma value is increased, judging that the drill bit approaches to the bottom plate stratum, and increasing the inclination angle of the drilling hole; when the measured gamma value on the stratum increases firstly and then increases, the direction of the drill bit is judged to be approaching to the roof stratum, and the inclination angle of the drilling hole is required to be reduced.
Calculating the distance of the pilot bit from the thin coal seam in the drilling direction by the following formula:
L＝D/sinα-L a
L b ＝L sinα
wherein: d is the vertical distance between the azimuth gamma measurement unit and the coal-rock interface; l (L) a Distance between the azimuth gamma measuring unit and the pilot bit; alpha is the included angle between the coal-rock interface and the front measurement nipple; l is the distance of the pilot bit to drill the thin coal seam in the drilling direction; l (L) b Is the vertical distance of the pilot bit from the coal-rock interface in the drilling direction.
Compared with the prior art, the application has the beneficial technical effects that:
(1) The drilling inclination angle, the tool facing angle and the natural gamma radioactive intensity of the stratum are measured by utilizing the front measurement nipple, the drilling azimuth angle is measured by utilizing the rear measurement nipple, the coal-rock interface identification while drilling is realized, the three-dimensional dynamic geological model is built by inverting the characteristics of the thin coal layer thickness change, the space spreading and the like, the drilling design track is corrected in real time, and the accurate extension of the real drilling track along the thin coal layer is ensured.
(2) The front measurement nipple is arranged near the drill bit, the distance between the measurement probe and the drill bit is shortened, the distance of the drill bit for drilling the thin coal seam is calculated by precisely positioning the space position of the drill bit and combining the identification parameters of the coal-rock interface, a certain safety distance is reserved for the direction adjustment of the drill bit, and the branching operation is avoided.
(3) The side wall communication structure design of the non-magnetic wire-passing screw drilling tool realizes the wired signal transmission and stable power supply between the rear measurement nipple and the front measurement nipple. The nonmagnetic through-line screw drilling tool adopts underground high-pressure air driving, reduces scouring and disturbance of the hole wall, does not influence desorption and release of gas in the hole, and solves the problems of hole collapse, spray hole and the like in the process of drilling the crushed soft thin coal layer.
(4) In conclusion, through the technical scheme of the application, the hole forming depth and the hole forming rate of the gas extraction drilling holes of the crushed soft and thin coal layer can be effectively improved, and the gas control period and the control cost are shortened.
Drawings
FIG. 1 is a schematic diagram of a drilling tool assembly for directional long-drilling construction for gas extraction of a crushed soft and thin coal seam.
Fig. 2 is a schematic view of a front measuring nipple.
Fig. 3 is a schematic diagram of a non-magnetic string-passing screw drilling tool.
Fig. 4 is a section A-A of fig. 3.
Fig. 5 is a schematic diagram of a communication assembly.
Fig. 6 is a front view of the crossover communication assembly shown schematically (a) in section B-B of fig. 3 (B).
Fig. 7 is a schematic view of a rear measuring nipple.
FIG. 8 is a schematic diagram of a construction method for long drilling holes for gas extraction of crushed soft and thin coal layers.
Reference numerals meaning:
1. the directional drill bit, 2, a front measuring nipple, 3, a non-magnetic wire-passing screw drilling tool, 4, a rear measuring nipple and 5, a central cable-passing drill rod; 201. the device comprises a transmission central shaft, a front measuring nipple outer tube 203, a communication joint 204, a communication cable 205, a signal transmission unit 206, a voltage stabilizing unit 207, an engineering parameter measuring unit 208 and an azimuth gamma measuring unit; 301. communication cable assembly, 302, communication nipple outer tube, 303, sidewall turn center communication nipple, 304, drive shaft, 305, cardan shaft, 306, screw motor, 3061, stator, 3062, rotor, 307, drive shaft outer tube, 308, cardan shaft outer tube, 309, screw motor outer tube, 310, jumper communication assembly, 311, insulating rubber ring I,312, insulating rubber ring II,313, male slip ring, 314, high strength spring, 315, female slip ring, 316, jumper cable; 401. the device comprises a rear measuring nipple outer tube, 402, a signal receiving unit, 403, an azimuth measuring unit, 404, a signal transmitting unit, 405, a centralizer and 406, and a fixing ring.
The application is described in detail below with reference to the drawings and the detailed description.
Detailed Description
The following specific embodiments of the present application are given according to the above technical solutions, and it should be noted that the present application is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solutions of the present application fall within the protection scope of the present application. The present application will be described in further detail with reference to examples.
Example 1:
the embodiment provides a drilling tool assembly for directional long drilling construction of gas extraction of a crushed soft thin coal seam, which comprises a directional drill bit 1, a front measuring nipple 2, a non-magnetic wire-passing screw drilling tool 3, a rear measuring nipple 4 and a central cable drill rod 5 which are sequentially connected from bottom to top as shown in fig. 1 to 7.
The front measuring nipple 2 comprises a transmission central shaft 201 with a central through hole, a front measuring nipple outer tube 202 sleeved outside the transmission central shaft 201, and a communication measuring unit arranged on the front measuring nipple outer tube 202; the nonmagnetic threading screw drilling tool 3 comprises a central power unit, a nonmagnetic drilling tool outer pipe sleeved outside the central power unit, a communication cable assembly 301 embedded in the nonmagnetic drilling tool outer pipe, a communication nipple outer pipe 302 and a side wall rotary center communication nipple 303 arranged in the communication nipple outer pipe 302; the rear measuring nipple 4 comprises a central communication measuring unit and a rear measuring nipple outer tube 401 sleeved outside the central communication measuring unit; the center cable drill pipe 5 comprises a center cable and a drill pipe outer pipe.
The pilot bit 1, the transmission central shaft 201 and the central power unit are connected in sequence; the front measuring nipple outer tube 202, the nonmagnetic drilling tool outer tube, the communication nipple outer tube 302, the rear measuring nipple outer tube 401 and the drill rod outer tube are sequentially connected; the communication measuring unit, the communication cable assembly 301, the side wall center-to-center communication nipple 303, the center communication measuring unit and the center cable are sequentially communicated.
In the scheme, the directional drill bit is provided with the gas one-way stop valve, so that the damage to the front measurement nipple and the nonmagnetic wire-passing screw drilling tool caused by the backflow of gas carrying hole bottom drilling slag from the water hole of the drill bit when the pressure in the drill rod is released is avoided; the front measurement nipple is used for measuring the drilling inclination angle at the near-bit position, the tool facing angle and the natural gamma-ray radioactive intensity of the stratum; the non-magnetic wire-passing screw drilling tool is used for providing rock crushing power for the drill bit, transmitting the measurement data of the front measurement nipple to the rear measurement nipple through the non-magnetic wire-passing screw drilling tool side wall communication assembly, and simultaneously serving as a power supply channel of the front measurement nipple; the side wall-to-center communication is short and energy-saving, and a transmission channel of a non-magnetic wire-passing screw drill side wall communication assembly is converted into a center transmission channel; the rear measurement nipple is used for receiving measurement data of the front measurement nipple and measuring the azimuth angle of the drilling hole; the central cable drill rod is used for uploading hole bottom measurement data.
The communication measurement unit is used for measuring the near-bit position drilling inclination angle, the tool facing angle and the natural gamma-ray radioactive intensity of the stratum; the system comprises a communication connector 203, a communication cable 204, a signal transmission unit 205, a voltage stabilizing unit 206, an engineering parameter measuring unit 207 and an azimuth gamma measuring unit 208 which are connected in sequence; the voltage stabilizing unit 206 can supply power to the signal transmission unit 205, the engineering parameter measurement unit 207 and the azimuth gamma measurement unit 208, and the communication connector 203 is arranged at the end part of the outer tube 202 of the front measuring nipple and can communicate with the nonmagnetic wire-passing screw drilling tool 3.
The front end of the transmission center shaft 201 is provided with a transmission joint so as to be connected with the pilot bit 1, and the transmission center shaft 201 can transmit the power output by the nonmagnetic wire-passing screw drilling tool 3 to the pilot bit 1; the side wall of the transmission central shaft 201 of the embodiment is provided with a through hole, and can be communicated with an annular gap between a central channel of the transmission central shaft 201 and the front measurement nipple outer tube 202; the inner wall of the outer tube 202 of the front measuring nipple is provided with a wear-resistant rubber coating.
The central power unit comprises a transmission shaft 304, a universal shaft 305 and a screw motor 306 which are sequentially connected; the nonmagnetic drill outer tube includes a transmission shaft outer tube 307 sleeved outside the transmission shaft 304, a cardan shaft outer tube 308 sleeved outside the cardan shaft 305, and a screw motor outer tube 309 sleeved outside the screw motor 306, which are sequentially connected.
The joint of the front-end measuring nipple 202 and the transmission shaft outer tube 307, the joint of the transmission shaft outer tube 307 and the universal shaft outer tube 308, the joint of the universal shaft outer tube 308 and the screw motor outer tube 309, and the joint of the screw motor outer tube 309 and the communication nipple 302 are all provided with a cross-joint communication assembly 310 to form a wired communication transmission channel among the communication measuring unit, the communication cable assembly 301 and the side wall rotary center communication nipple 303.
The cross joint communication assembly 310 comprises two opposite insulating rubber rings, wherein an annular groove I is formed in an insulating rubber ring I311, and an annular groove II is formed in an insulating rubber ring II 312; a male slip ring 313 is arranged in the annular groove I, a high-strength spring 314 is arranged between the male slip ring 313 and the bottom of the annular groove I, and a female slip ring 315 is arranged in the annular groove II; the male slip ring 313 and the female slip ring 315 are in mating contact, and the male slip ring 313 and the female slip ring 315 are respectively connected with a jumper cable 316 extending out of the two insulating rubber rings.
The high-stiffness spring has the functions of pushing the male slip ring, enabling the male slip ring to be well contacted with the female slip ring, pushing the male slip ring to move when the male slip ring is worn, enabling the male slip ring to be automatically repaired, achieving stable transmission and stable power supply of measurement signals, and fixing the insulating rubber ring through 4 bolts in the circumferential direction through bolt fixing holes in the insulating rubber ring.
Specifically, in the jumper communication assembly between the front measurement nipple outer tube and the transmission shaft outer tube, two insulating rubber rings are respectively arranged at the ends of the front measurement nipple outer tube and the transmission shaft outer tube, and a jumper cable can be communicated with a communication measurement unit and a communication cable assembly at two sides; in the jumper communication assembly between the transmission shaft outer tube and the universal shaft outer tube, two insulating rubber rings are respectively arranged at the ends of the transmission shaft outer tube and the universal shaft outer tube, and a jumper cable of the jumper communication assembly can be communicated with communication cable assemblies at two sides; in the jumper communication assembly between the outer tube of the universal shaft and the outer tube of the screw motor, two insulating rubber rings are respectively arranged at the end parts of the outer tube of the universal shaft and the outer tube of the screw motor, and a jumper cable of the jumper communication assembly can be communicated with communication cable assemblies at two sides; in the jumper communication assembly between the screw motor outer tube and the communication nipple outer tube, two insulating rubber rings are respectively arranged at the ends of the screw motor outer tube and the communication nipple outer tube, and a jumper cable can be used for communicating communication cable assemblies at two sides and the side wall rotary center communication nipple.
The screw motor 306 includes a stator 3061 provided on an inner wall of the screw motor outer tube 309 and a rotor 3062 provided within the stator 3061. Rated torque of the screw motor is more than or equal to 200Nm, pressure drop is less than or equal to 0.3MPa, and the head ratio of the stator to the rotor is 5: and 6, driving by using underground high-pressure air, and adding a lubricant into the high-pressure air to slow down abnormal abrasion generated by high-speed rotation of the nonmagnetic wire-passing screw drilling tool.
The communication cable assembly 301 comprises a communication cable and further comprises a wear-resistant rubber covering layer, a protective metal tube and a wear-resistant alloy coating which are sequentially coated outside the communication cable from inside to outside.
The central communication measuring unit of the rear measuring nipple 4 comprises a signal receiving unit 402, an azimuth measuring unit 403 and a signal transmitting unit 404 which are sequentially connected; the azimuth measuring unit 403 can measure the azimuth of a drilling hole, the signal receiving unit 402 is connected with the side wall rotary center communication nipple 303 and can supply power to the side wall rotary center communication nipple, the near-bit measuring information transmitted by the front measuring nipple 2 can be received, and the signal transmitting unit 404 transmits measuring data in the drilling hole to the hole opening through the center cable drill rod 5; the rear measuring nipple 4 is powered by an orifice explosion-proof computer.
A centralizer 405 is arranged between the signal receiving unit 402 and the post-measurement nipple outer tube 401, and a fixing ring 406 is arranged between the signal transmitting unit 404 and the post-measurement nipple outer tube 401; the fixing ring 406 is used for fixing the central communication measuring unit, and the centralizer 405 is used for centralizing the central communication measuring unit.
Example 2:
the method for constructing the directional long drilling holes by extracting the gas from the crushed soft thin coal seam is realized by the construction drilling tool combination in the embodiment 1; the method comprises the following steps:
drilling track design before construction: collecting geological information in a gas extraction drilling construction area, wherein the geological information comprises adjacent construction drilling data, ground exploration information, geological structure information disclosed by roadway tunneling and the like, and establishing an initial three-dimensional geological model in the gas extraction drilling area according to the geological information; designing a drilling track in the initial three-dimensional geological model, and ensuring that the drilling track extends in the thin coal seam;
step one: drilling trajectory parameters and formation natural gamma-ray radioactivity intensity measurements: in the drilling process, measuring the inclination angle of a near-bit position hole Duan Zuankong and the facing angle of a tool by using an engineering parameter measuring unit in a front measuring nipple to obtain the change condition of a drilling track in the vertical direction; the method comprises the steps of measuring natural gamma radioactivity intensity of stratum near a drill bit by using an azimuth gamma measuring unit in a front measuring nipple, wherein the natural radioactivity intensity of stratum above the azimuth gamma measuring unit is represented by an upper gamma value, the natural radioactivity intensity of stratum below the azimuth gamma measuring unit is represented by a lower gamma value, measuring azimuth angle of drilling by using a rear measuring nipple azimuth measuring unit, and obtaining the change condition of drilling track in the horizontal direction;
step two: and (3) measuring data real-time transmission: encoding the natural gamma radioactive intensity data of the drilling inclination angle, the azimuth angle, the tool facing angle and the stratum by utilizing a rear measurement nipple signal transmitting unit, and uploading the data to an orifice explosion-proof computer through a central cable drill rod;
step three: measurement data processing and inversion: identifying formation lithology and coal stratum interface by using the collected formation natural gamma radioactivity intensity, accurately positioning the position of the pilot bit by combining the collected drilling inclination angle, azimuth angle and relation with hole depth, determining the vertical distance between the pilot bit and the coal stratum interface, predicting the included angle between the extending direction of the drill bit and the coal stratum interface, further reversing the characteristics of spatial spread of the roof and floor strata, thickness change of thin coal stratum and the like, updating an initial three-dimensional geological model, and establishing a three-dimensional dynamic geological model.
Geosteering drilling: real-time correction is carried out on the drilling design track based on the three-dimensional dynamic geological model, and the design track is adjusted to extend along the actually detected thin coal seam; and controlling the nonmagnetic line-passing screw drilling tool to conduct guide drilling according to the corrected design track until the design hole depth is reached.
Referring to fig. 8, in the three-dimensional dynamic geological model, slicing is performed along the main design azimuth of the drilling hole, a two-dimensional section view of the drilling track is obtained, the distance of the drill bit for drilling the thin coal seam is calculated according to the vertical distance between the drill bit and the coal stratum interface and the included angle between the extending direction of the drill bit and the coal stratum interface, which are obtained in the fourth step, and a certain safety distance is reserved for the direction adjustment of the drill bit.
In the drilling process, when the gamma value under the stratum measured by the front measurement nipple is increased firstly and then the gamma value is increased, judging that the drill bit approaches to the bottom plate stratum, and increasing the inclination angle of the drilling hole; when the measured gamma value on the stratum increases firstly, and then the measured gamma value increases, judging that the direction of the drill bit approaches to the roof stratum, and reducing the inclination angle of drilling;
calculating the distance of the pilot bit from the thin coal seam in the drilling direction by the following formula:
L＝D/sinα-L a
L b ＝Lsinα
wherein: d is the vertical distance between the azimuth gamma measurement unit and the coal-rock interface; l (L) a Distance between the azimuth gamma measuring unit and the pilot bit; alpha is the included angle between the coal-rock interface and the front measurement nipple; l is the distance of the pilot bit to drill the thin coal seam in the drilling direction; l (L) b Is the vertical distance of the pilot bit from the coal-rock interface in the drilling direction.
Claims (8)
1. The drilling tool combination for the directional long drilling construction of the gas extraction of the crushed soft and thin coal seam is characterized by comprising a directional drill bit (1), a front measuring nipple (2), a non-magnetic wire-passing screw drilling tool (3), a rear measuring nipple (4) and a central cable drill rod (5) which are sequentially connected from bottom to top;
the front measuring nipple (2) comprises a transmission central shaft (201) with a central through hole, a front measuring nipple outer tube (202) sleeved outside the transmission central shaft (201), and a communication measuring unit arranged on the front measuring nipple outer tube (202); the nonmagnetic threading screw drilling tool (3) comprises a central power unit, a nonmagnetic drilling tool outer pipe sleeved outside the central power unit, a communication cable assembly (301) embedded in the nonmagnetic drilling tool outer pipe, a communication nipple outer pipe (302) and a side wall rotary center communication nipple (303) arranged in the communication nipple outer pipe (302); the rear measuring nipple (4) comprises a central communication measuring unit and a rear measuring nipple outer tube (401) sleeved outside the central communication measuring unit; the center cable drill rod (5) comprises a center cable and a drill rod outer pipe;
the directional drill bit (1), the transmission central shaft (201) and the central power unit are sequentially connected; the front measuring nipple outer tube (202), the non-magnetic drilling tool outer tube, the communication nipple outer tube (302), the rear measuring nipple outer tube (401) and the drill rod outer tube are connected in sequence; the communication measuring unit, the communication cable assembly (301), the side wall center-to-center communication nipple (303), the center communication measuring unit and the center cable are sequentially communicated;
the communication measurement unit is used for measuring the near-bit position drilling inclination angle, the tool facing angle and the natural gamma-ray radioactive intensity of the stratum; the system comprises a communication connector (203), a communication cable (204), a signal transmission unit (205), a voltage stabilizing unit (206), an engineering parameter measuring unit (207) and an azimuth gamma measuring unit (208) which are connected in sequence; the pressure stabilizing unit (206) can supply power to the signal transmission unit (205), the engineering parameter measurement unit (207) and the azimuth gamma measurement unit (208), and the communication connector (203) is arranged at the end part of the front measurement nipple outer tube (202) and can be communicated with the nonmagnetic wire-passing screw drilling tool (3);
the central communication measuring unit of the rear measuring nipple (4) comprises a signal receiving unit (402), an azimuth measuring unit (403) and a signal transmitting unit (404) which are connected in sequence; the azimuth measuring unit (403) can measure the azimuth of a drilling hole, the signal receiving unit (402) is connected with the side wall rotary center communication nipple (303) and can supply power to the side wall rotary center communication nipple, the near-bit measuring information transmitted by the front measuring nipple (2) can be received, and the signal transmitting unit (404) transmits measuring data in the drilling hole to the hole opening through the center cable drill rod (5); the rear measuring nipple (4) is powered by an orifice explosion-proof computer;
a centralizer (405) is arranged between the signal receiving unit (402) and the rear measuring nipple outer tube (401), and a fixing ring (406) is arranged between the signal transmitting unit (404) and the rear measuring nipple outer tube (401); the fixing ring (406) is used for fixing the central communication measuring unit, and the centralizer (405) is used for centralizing the central communication measuring unit.
2. The drilling tool assembly for directional long drilling construction for gas extraction of the crushed soft and thin coal seam according to claim 1, wherein a transmission joint is arranged at the front end of the transmission central shaft (201) so as to be connected with the directional drill bit (1), and the transmission central shaft (201) can transmit power output by the nonmagnetic wire-passing screw drilling tool (3) to the directional drill bit (1); the inner wall of the outer tube (202) of the front measuring nipple is provided with a wear-resistant rubber coating.
3. The crushed soft and thin coal seam gas extraction directional long drilling construction drilling tool assembly according to claim 1, wherein the central power unit comprises a transmission shaft (304), a universal shaft (305) and a screw motor (306) which are sequentially connected; the outer tube of the non-magnetic drilling tool comprises a transmission shaft outer tube (307) sleeved outside a transmission shaft (304), a universal shaft outer tube (308) sleeved outside a universal shaft (305) and a screw motor outer tube (309) sleeved outside a screw motor (306) which are connected in sequence.
4. A crushed soft and thin coal seam gas extraction directional long drilling construction drilling tool assembly according to claim 3, wherein a joint communication assembly (310) is arranged at the joint of the front measurement nipple outer tube (202) and the transmission shaft outer tube (307), the joint of the transmission shaft outer tube (307) and the universal shaft outer tube (308), the joint of the universal shaft outer tube (308) and the screw motor outer tube (309) and the joint of the screw motor outer tube (309) and the communication nipple outer tube (302) so as to form a wired communication transmission channel among the communication measurement unit, the communication cable assembly (301) and the side wall rotary center communication nipple (303).
5. The drilling assembly for directional long-drilling construction of gas extraction of a crushed soft and thin coal seam as claimed in claim 4, wherein the jumper communication assembly (310) comprises two opposite insulating rubber rings, an annular groove I is arranged on the insulating rubber ring I (311), and an annular groove II is arranged on the insulating rubber ring II (312); a male slip ring (313) is arranged in the annular groove I, a high-strength spring (314) is arranged between the male slip ring (313) and the bottom of the annular groove I, and a female slip ring (315) is arranged in the annular groove II; the male slip ring (313) and the female slip ring (315) are in matched contact, and the male slip ring (313) and the female slip ring (315) are respectively connected with a jumper cable (316) which extends out of the two insulating rubber rings.
6. A crushed soft and thin coal seam gas extraction directional long drilling construction drill tool assembly according to claim 3, characterized in that the screw motor (306) comprises a stator (3061) provided on the inner wall of the screw motor outer tube (309) and a rotor (3062) provided inside the stator (3061).
7. The crushed soft and thin coal seam gas extraction directional long drilling construction drilling tool assembly according to claim 1, wherein the communication cable assembly (301) comprises a communication cable, and further comprises a wear-resistant rubber covering layer, a protective metal pipe and a wear-resistant alloy coating which are sequentially coated outside the communication cable from inside to outside.
8. A construction method for directional long drilling of gas extraction of a crushed soft thin coal seam, which is characterized in that the method is realized by the construction drilling tool assembly of claim 7; the method comprises the following steps:
step one: in the drilling process, measuring the inclination angle of a near-bit position hole Duan Zuankong and the facing angle of a tool by using an engineering parameter measuring unit in a front measuring nipple to obtain the change condition of a drilling track in the vertical direction; carrying out natural gamma radioactive intensity measurement on stratum near the bit position by using an azimuth gamma measurement unit in the front measurement nipple; the natural radioactivity intensity of the stratum above the azimuth gamma measuring unit is represented by an upper gamma value, the natural radioactivity intensity of the stratum below the azimuth gamma measuring unit is represented by a lower gamma value, the azimuth angle of the drilling hole is measured by a rear measuring nipple azimuth measuring unit, and the change condition of the drilling hole track in the horizontal direction is obtained;
step two: and (3) measuring data real-time transmission: uploading the natural gamma radioactive intensity data of the drilling inclination angle, the azimuth angle, the tool facing angle and the stratum to an orifice explosion-proof computer through a central cable drill rod by utilizing a rear measurement nipple signal transmitting unit;
step three: and (3) measurement data processing: identifying formation lithology and coal stratum interface by using the collected formation natural gamma radioactivity intensity, accurately positioning the position of the pilot bit by combining the collected drilling inclination angle, azimuth angle and relation with hole depth, determining the vertical distance between the pilot bit and the coal stratum interface, predicting the included angle between the extension direction of the drill bit and the coal stratum interface, inverting the spatial spread of the top and bottom strata and the thickness change characteristic of the thin coal stratum, updating the initial three-dimensional geological model, and establishing a three-dimensional dynamic geological model; real-time correction is carried out on the drilling design track based on the three-dimensional dynamic geological model, and the design track is adjusted to extend along the actually detected thin coal seam; controlling the nonmagnetic line-passing screw drilling tool to conduct guide drilling according to the corrected design track until the design hole depth is reached;
in the drilling process, when the gamma value under the stratum measured by the front measurement nipple is increased firstly and then the gamma value is increased, judging that the drill bit approaches to the bottom plate stratum, and increasing the inclination angle of the drilling hole; when the measured gamma value on the stratum increases firstly, and then the measured gamma value increases, judging that the direction of the drill bit approaches to the roof stratum, and reducing the inclination angle of drilling;
calculating the distance of the pilot bit from the thin coal seam in the drilling direction by the following formula:
L＝D/sinα-L a
L b ＝Lsinα
wherein: d is the vertical distance between the azimuth gamma measurement unit and the coal-rock interface; l (L) a Distance between the azimuth gamma measuring unit and the pilot bit; alpha is the included angle between the coal-rock interface and the front measurement nipple; l is the distance of the pilot bit to drill the thin coal seam in the drilling direction; l (L) b Is the vertical distance of the pilot bit from the coal-rock interface in the drilling direction.
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