阅读说明：本技术 一种碎软薄煤层瓦斯抽采定向长钻孔施工钻具组合及方法 (Broken soft thin coal seam gas extraction directional long drilling construction drilling tool combination and method ) 是由 刘飞 李泉新 褚志伟 方俊 刘建林 姜磊 陈龙 于 2021-08-23 设计创作，主要内容包括：本发明公开一种碎软薄煤层瓦斯抽采定向长钻孔施工钻具组合及方法,包括依次相连的定向钻头、前置测量短节、无磁过线螺杆钻具、后置测量短节和中心通缆钻杆；前置测量短节用于近钻头位置钻孔倾角、工具面向角和地层自然伽马放射性强度的测量；无磁过线螺杆钻具用于给定向钻头提供碎岩动力,并将前置测量短节的测量数据通过无磁过线螺杆钻具侧壁通信组件输送至后置测量短节；后置测量短节用于前置测量短节测量数据接收和钻孔方位角的测量；中心通缆钻杆用于孔底测量数据的上传。通过本发明的技术方案能有效提高碎软薄煤层瓦斯抽采钻孔成孔深度和成孔率,缩短瓦斯治理周期,降低瓦斯治理成本。(The invention discloses a broken soft thin coal seam gas extraction directional long drilling construction drilling tool assembly and a method, wherein the broken soft thin coal seam gas extraction directional long drilling construction drilling tool assembly comprises a directional drill bit, a front-mounted measuring short section, a non-magnetic thread-passing screw drilling tool, a rear-mounted measuring short section and a central cable-passing drilling rod which are sequentially connected; the front measuring nipple is used for measuring the drill hole inclination angle at the position close to the drill bit, the tool face angle and the natural gamma radioactivity intensity of the stratum; the non-magnetic wire-passing screw drilling tool is used for providing rock crushing power for the drill bit and conveying the measurement data of the front measurement short section to the rear measurement short section through the side wall communication component of the non-magnetic wire-passing screw drilling tool; the rear measuring short section is used for receiving the measuring data of the front measuring short section and measuring the azimuth angle of the drilled hole; the central cable drill rod is used for uploading hole bottom measurement data. By adopting the technical scheme, the hole forming depth and the hole forming rate of the broken soft thin coal seam gas extraction drill hole can be effectively improved, the gas treatment period is shortened, and the gas treatment cost is reduced.)

1. A directional long drilling hole construction drilling tool assembly for gas extraction of a broken soft thin coal seam is characterized by comprising a directional drilling bit (1), a front-mounted measuring nipple (2), a non-magnetic wire-passing screw drilling tool (3), a rear-mounted measuring nipple (4) and a central cable-passing drilling rod (5) which are sequentially connected from bottom to top;

the preposed measuring short section (2) comprises a transmission central shaft (201) with a central through hole, a preposed measuring short section outer pipe (202) sleeved outside the transmission central shaft (201) and a communication measuring unit arranged on the preposed measuring short section outer pipe (202); the non-magnetic wire-passing screw drilling tool (3) comprises a central power unit, a non-magnetic drilling tool outer pipe sleeved outside the central power unit, a communication cable assembly (301) embedded in the non-magnetic drilling tool outer pipe, a communication short section outer pipe (302) and a side wall center-turning communication short section (303) arranged in the communication short section outer pipe (302); the rear measuring nipple (4) comprises a central communication measuring unit and a rear measuring nipple outer pipe (401) sleeved outside the central communication measuring unit; the central cable-passing drill rod (5) comprises a central cable and a drill rod outer pipe;

the directional drill bit (1), the transmission central shaft (201) and the central heart force unit are connected in sequence; the preposed measuring short section outer pipe (202), the non-magnetic drilling tool outer pipe, the communication short section outer pipe (302), the postposed measuring short section outer pipe (401) and the drill rod outer pipe are sequentially connected; the communication measuring unit, the communication cable assembly (301), the side wall center-turning communication short section (303), the center communication measuring unit and the center cable are communicated in sequence.

2. The assembly of the broken soft thin coal seam gas extraction directional long borehole construction drilling tool as claimed in claim 1, wherein the communication measurement unit is used for measuring a near-bit position borehole inclination angle, a tool face angle and a formation natural gamma radioactivity intensity; the device 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 orientation 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 measuring unit (207) and the azimuth gamma measuring unit (208), and the communication joint (203) is arranged at the end part of the front measuring nipple outer pipe (202) and can communicate with the non-magnetic threaded screw drilling tool (3).

3. The broken soft thin coal seam gas extraction directional long borehole construction drilling tool assembly according to claim 1, characterized in that a transmission joint is arranged at the front end of the transmission central shaft (201) to be connected with the directional drill bit (1), and the transmission central shaft (201) can transmit the power output by the non-magnetic thread-passing screw drilling tool (3) to the directional drill bit (1); and the inner wall of the front measuring nipple outer pipe (202) is provided with a wear-resistant rubber coating.

4. The directional long borehole construction drilling assembly for gas extraction in the crushed soft thin coal seam 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 connected in sequence; the non-magnetic drilling tool outer pipe comprises a transmission shaft outer pipe (307) sleeved outside a transmission shaft (304), a universal shaft outer pipe (308) sleeved outside a universal shaft (305) and a screw motor outer pipe (309) sleeved outside a screw motor (306) which are sequentially connected.

5. The assembly of the smashed soft thin coal seam gas extraction directional long borehole construction drilling tool as claimed in claim 4, wherein a joint of the front measurement nipple outer pipe (202) and the transmission shaft outer pipe (307), a joint of the transmission shaft outer pipe (307) and the universal shaft outer pipe (308), a joint of the universal shaft outer pipe (308) and the screw motor outer pipe (309), and a joint of the screw motor outer pipe (309) and the communication nipple outer pipe (302) are all provided with a cross-joint communication assembly (310) to form a wired communication transmission channel among the communication measurement unit, the communication cable assembly (301) and the side wall rotation center communication nipple (303).

6. The assembly of the broken soft thin coal seam gas extraction directional long borehole construction drilling tool as claimed in claim 5, wherein the crossover joint communication assembly (310) comprises two opposite insulating rubber rings, an annular groove I is formed in the insulating rubber ring I (311), and an annular groove II is formed in 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) is in fit contact with the female slip ring (315), 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.

7. The directional long drilling construction drill tool assembly for gas extraction in the crushed soft thin coal seam according to claim 4, wherein the screw motor (306) comprises a stator (3061) arranged on the inner wall of the outer pipe (309) of the screw motor and a rotor (3062) arranged in the stator (3061).

8. The directional long drilling construction drilling tool assembly for gas extraction in the crushed soft thin coal seam 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.

9. The assembly of the broken soft thin coal seam gas extraction directional long borehole construction drilling tool as claimed in claim 2, wherein 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 drilling azimuth angle, the signal receiving unit (402) is connected with the sidewall centering communication short section (303) and can supply power to the sidewall centering communication short section, the signal receiving unit can also receive near-bit measuring information transmitted by the front measuring short section (2), and the signal transmitting unit (404) transmits measurement data in a hole to the hole opening through the central cable drill rod (5); the rear-mounted measuring short joint (4) supplies power through an orifice explosion-proof computer;

a centralizer (405) is arranged between the signal receiving unit (402) and the rear measuring nipple outer pipe (401), and a fixing ring (406) is arranged between the signal transmitting unit (404) and the rear measuring nipple outer pipe (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.

10. A directional long drilling construction method for gas extraction of a broken soft thin coal seam is characterized in that the method is realized by the construction drilling tool combination of claim 9; the method comprises the following steps:

the method comprises the following steps: in the drilling process, a process parameter measuring unit in a front measuring short section is used for measuring the drilling inclination angle of a hole section at the position close to a drill bit and the tool face angle, and the change condition of a drilling track in the vertical direction is obtained; measuring the natural gamma radioactivity intensity of the stratum at the position close to the drill bit by using an azimuth gamma measuring unit in the front measuring 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 of the borehole is measured by using the rear measuring pup joint azimuth measuring unit, and the change condition of the borehole trajectory in the horizontal direction is obtained;

step two: real-time transmission of measurement data: the rear-mounted measuring short-section signal transmitting unit is used for uploading the drilling inclination angle, the azimuth angle, the tool face angle and the formation natural gamma radioactive intensity data to an orifice explosion-proof computer through a central cable-through drill rod;

step three: processing measurement data: identifying the lithology and the coal-rock layer interface of the stratum by utilizing the collected stratum natural gamma radioactivity intensity, accurately positioning the position of the directional drill bit by combining the collected borehole inclination angle, azimuth angle and hole depth relation, determining the vertical distance between the directional drill bit and the coal-rock layer interface, predicting the included angle between the extension direction of the drill bit and the coal-rock layer interface, reversely performing the space distribution of a top floor and a bottom floor and the thickness change characteristic of a thin coal layer, updating an initial three-dimensional geological model, and establishing a three-dimensional dynamic geological model; correcting a drilling design track in real time based on the three-dimensional dynamic geological model, and adjusting the design track to extend along the actually detected thin coal seam; controlling the non-magnetic thread-passing screw drill to perform guide drilling according to the corrected design track until the design hole depth is reached;

in the drilling process, when the lower gamma value of the stratum measured by the front measuring nipple is increased firstly and the upper gamma value is increased later, the drill bit is judged to approach the bottom plate rock stratum, and the drilling inclination angle needs to be increased; when the measured gamma value on the stratum is increased firstly and the measured gamma value is increased after the measured gamma value is decreased, judging that the direction of the drill bit approaches to a roof stratum and the inclination angle of a drill hole needs to be decreased;

and calculating the distance of the directional drill bit out of the thin coal seam in the drilling direction by the following formula:

L＝D/sinα-L_a

L_b＝Lsinα

in the formula: d is the vertical distance between the azimuth gamma measuring unit and the coal-rock interface; l is_aThe distance between the azimuth gamma measuring unit and the directional drill bit; alpha is an included angle between the coal rock interface and the front measuring short joint; l is a drillThe distance of the directional drill bit drilling the thin coal seam in the advancing direction; l is_bThe vertical distance from the directional drill bit to the coal-rock interface in the drilling direction.

Technical Field

The invention belongs to the field of underground gas extraction of coal mines, and particularly relates to a directional long drilling construction drilling tool assembly and method for gas extraction of a broken soft thin coal seam.

Background

The thin coal seam is widely distributed in China, mainly refers to a coal seam with the thickness less 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 thickness more than 0.8m are required to be mined according to the regulations in China, and coal beds with the thickness less than 0.8m encourage mining. However, the treatment of the broken soft thin coal seam gas becomes a main problem which restricts the safe and efficient exploitation of the broken soft thin coal seam gas because the broken soft thin coal seam gas extraction drill hole is shallow in hole forming depth and low in hole forming rate.

The thickness of the broken soft thin coal layer is small, the fluctuation change is large, the drilling track of the conventional rotary drilling technology is uncontrollable, and the drilling track is easy to touch the top or the bottom, so that the effective gas extraction hole section is few, and the drilling inclination angle, the azimuth angle, the tool surface and other parameters mainly collected by the conventional measurement while drilling system are used for guiding the adjustment of the drilling track, and the condition of drilling the stratum to be met is judged by only depending on the change condition of water return of the drilling hole, so that the accurate judgment of the lithology of the stratum and the coal-rock interface is difficult to realize. Secondly, the distance between the measurement while drilling probe and the drill bit is about 6m, the regulation and control of the drilling track are delayed, the drill bit is easy to drill a thin coal seam, the operation of drilling branch holes is difficult, and the accurate extension of the drilling track along the thin coal seam is difficult to ensure. In addition, clean water is adopted as flushing fluid in the underground directional drilling technology, so that the flushing disturbance on the hole wall of the broken soft thin coal seam is large, hole collapse and orifice spraying accidents are frequent, and the underground directional drilling technology 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 invention provides a broken soft thin coal seam gas extraction directional long drilling construction drilling tool combination and a method, which overcome the technical defects and problems of the existing directional drilling tool combination in broken soft thin coal seam gas extraction drilling construction, realize the long-distance accurate extension of a gas extraction drilling track along a thin coal seam, simultaneously reduce the probability of hole collapse and spraying, improve the hole forming depth and hole forming efficiency of a broken soft thin coal seam, and solve the defect problems in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a directional long drilling hole construction drilling tool assembly for gas extraction of a broken soft thin coal seam comprises a directional drill bit, a front measuring short section, a non-magnetic thread-passing screw drilling tool, a rear measuring short section and a central cable-passing drilling rod which are sequentially connected from bottom to top;

the prepositive measuring short section comprises a transmission central shaft with a central through hole, a prepositive measuring short section outer pipe sleeved outside the transmission central shaft and a communication measuring unit arranged on the prepositive measuring short section outer pipe; the non-magnetic wire passing 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 short section outer pipe and a side wall center-turning communication short section arranged in the communication short section outer pipe; the rear measuring short section comprises a central communication measuring unit and a rear measuring short section outer pipe sleeved outside the central communication measuring unit; the central cable-passing drill rod comprises a central cable and a drill rod outer tube;

the directional drill bit, the transmission central shaft and the central heart force unit are sequentially connected; the preposed measuring short section outer pipe, the non-magnetic drilling tool outer pipe, the communication short section outer pipe, the postposed measuring short section outer pipe and the drill rod outer pipe are sequentially connected; the communication measuring unit, the communication cable assembly, the side wall center-turning communication short section, the center communication measuring unit and the center cable are sequentially communicated.

The invention also comprises the following technical characteristics:

optionally, the communication measurement unit is configured to measure a borehole inclination angle at a near-bit position, a tool face angle, and a formation natural gamma radioactivity intensity; the system comprises a communication joint, a communication cable, a signal transmission unit, a voltage stabilizing unit, an engineering parameter measuring unit and an orientation gamma measuring unit which are sequentially connected; the pressure stabilizing unit can supply power to the signal transmission unit, the engineering parameter measuring unit and the azimuth gamma measuring unit, and the communication joint is arranged at the end part of the outer pipe of the front measuring nipple and can communicate with the nonmagnetic threaded rod drilling tool.

Optionally, the front end of the transmission central shaft is provided with a transmission joint to be connected with the directional drill bit, and the transmission central shaft can transmit the power output by the non-magnetic wire-passing screw drill to the directional drill bit; and the inner wall of the outer pipe of the preposed measuring short section 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 connected in sequence; the non-magnetic drilling tool outer pipe comprises a transmission shaft outer pipe, a universal shaft outer pipe and a screw motor outer pipe, wherein the transmission shaft outer pipe, the universal shaft outer pipe and the screw motor outer pipe are sequentially connected and are sleeved outside a transmission shaft.

Optionally, the joints of the external pipe of the preposed measuring nipple and the external pipe of the transmission shaft, the joints of the external pipe of the transmission shaft and the external pipe of the universal shaft, the joints of the external pipe of the universal shaft and the external pipe of the screw motor, and the joints of the external pipe of the screw motor and the external pipe of the communication nipple are all provided with cross-joint communication components so as to form a wired communication transmission channel among the communication measuring unit, the communication cable component and the side wall rotation center communication nipple;

optionally, the crossover head communication assembly includes two opposite insulating rubber rings, an annular groove I is formed in the insulating rubber ring I, and an annular groove II is formed in the insulating rubber ring II; a male slip ring is arranged in the annular groove I, a high-strength spring is arranged between the male slip ring and the bottom of the annular groove I, and a female slip ring is arranged in the annular groove II; 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 extending out of the two insulating rubber rings.

Optionally, the screw motor includes a stator disposed on an inner wall of an outer tube of the screw motor and a rotor disposed in the stator.

Optionally, the communication cable assembly includes a communication cable, and further includes 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 connected in sequence; the azimuth measuring unit can measure a drilling azimuth angle, the signal receiving unit is connected with the side wall centering communication short section and can supply power to the side wall centering communication short section and can also receive near-bit measuring information transmitted by the front measuring short section, and the signal transmitting unit transmits measured data in a hole to the hole opening through the central cable drill rod; the rear measuring short section supplies power through an orifice explosion-proof computer;

a centralizer is arranged between the signal receiving unit and the rear measuring nipple outer pipe, and a fixing ring is arranged between the signal transmitting unit and the rear measuring nipple outer pipe; the fixing ring is used for fixing the central communication measuring unit, and the centralizer is used for centralizing the central communication measuring unit.

A directional long drilling construction method for extracting broken soft thin coal seam gas is characterized in that the method is realized by the construction drilling tool combination; the method comprises the following steps:

the method comprises the following steps: borehole trajectory parameters and formation natural gamma radioactivity measurements: in the drilling process, a process parameter measuring unit in a front measuring short section is used for measuring the drilling inclination angle of a hole section at the position close to a drill bit and the tool face angle, and the change condition of a drilling track in the vertical direction is obtained; measuring the natural gamma radioactivity intensity of the stratum at the position close to the drill bit by using an azimuth gamma measuring unit in the front measuring 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 of the borehole is measured by using the rear measuring pup joint azimuth measuring unit, and the change condition of the borehole trajectory in the horizontal direction is obtained;

step two: real-time transmission of measurement data: the method comprises the following steps of coding data such as a drill hole inclination angle, an azimuth angle, a tool orientation angle and a stratum natural gamma radioactivity intensity by using a rear-mounted measuring short-section signal transmitting unit, and uploading the data to an orifice explosion-proof computer through a central cable drill rod;

step three: processing measurement data: identifying the lithology of the stratum and the interface of the coal rock stratum by utilizing the collected natural gamma radioactivity intensity of the stratum, accurately positioning the position of a drill bit by combining the collected drill hole inclination angle, azimuth angle and hole depth relation, determining the vertical distance between the drill bit and the interface of the coal rock stratum, predicting the included angle between the extension direction of the drill bit and the interface of the coal rock stratum, inversing the characteristics of space distribution of a top floor and a bottom floor rock stratum and thickness change of a thin coal layer, updating an initial three-dimensional geological model, and establishing a three-dimensional dynamic geological model; correcting a drilling design track in real time based on the three-dimensional dynamic geological model, and adjusting the design track to extend along the actually detected thin coal seam; and controlling the non-magnetic thread-passing screw drill to perform guide drilling according to the corrected design track until the design hole depth is reached.

In the drilling process, when the lower gamma value of the stratum measured by the front measuring nipple is increased firstly and the upper gamma value is increased later, the drill bit is judged to approach the bottom plate rock stratum, and the drilling inclination angle needs to be increased; when the measured gamma value on the stratum is increased firstly and the measured gamma value is increased after the measured gamma value is decreased, the direction of the drill bit is judged to approach the top plate stratum, and the inclination angle of the drill hole needs to be decreased.

And calculating the distance of the directional drill bit out of the thin coal seam in the drilling direction by the following formula:

L＝D/sinα-L_a

L_b＝L sinα

in the formula: d is the vertical distance between the azimuth gamma measuring unit and the coal-rock interface; l is_aThe distance between the azimuth gamma measuring unit and the directional drill bit; alpha is an included angle between the coal rock interface and the front measuring short joint; l is the distance of the directional drill bit in the drilling direction to drill the thin coal seam; l is_bThe vertical distance from the directional drill bit to the coal-rock interface in the drilling direction.

Compared with the prior art, the invention has the beneficial technical effects that:

(1) the method comprises the steps of measuring a drilling inclination angle, a tool orientation angle and stratum natural gamma radioactivity intensity by using a front-mounted measuring nipple, measuring a drilling azimuth angle by using a rear-mounted measuring nipple, identifying a coal-rock interface while drilling, establishing a three-dimensional dynamic geological model by inverting characteristics such as thickness change and spatial distribution of a thin coal seam, correcting a drilling design track in real time, and ensuring that an actual drilling track extends along the thin coal seam accurately.

(2) The short section near the drill bit is arranged in the front-mounted measuring mode, the distance between the measuring probe and the drill bit is shortened, the distance that the drill bit drills out a thin coal seam is calculated by accurately positioning the spatial position of the drill bit and combining coal rock interface identification parameters, a certain safety distance is reserved for adjusting the direction of the drill bit, and the operation of branching is avoided.

(3) The design of the communication structure on the side wall of the nonmagnetic wire passing screw drilling tool realizes the wired signal transmission and stable power supply between the rear-mounted measuring short section and the front-mounted measuring short section. The non-magnetic thread-passing screw drill is driven by underground high-pressure air, so that the scouring and disturbance of the hole wall are reduced, the desorption and release of gas in the hole are not influenced, and the problems of hole collapse, orifice spraying and the like in the drilling process of the broken soft thin coal seam are solved.

(4) In conclusion, the technical scheme of the invention can effectively improve the hole forming depth and the hole forming rate of the broken soft thin coal seam gas extraction drill hole, and shorten the gas treatment period and the treatment cost.

Drawings

FIG. 1 is a schematic view of a broken soft thin coal seam gas extraction directional long borehole construction drilling tool assembly.

Fig. 2 is a schematic diagram of a front measurement nipple.

FIG. 3 is a schematic view of a non-magnetic wire-passing screw drill.

Fig. 4 is a sectional view taken along line a-a of fig. 3.

Fig. 5 is a schematic diagram of a communication assembly.

FIG. 6 is a cross-over head communication assembly schematic (a) section B-B of FIG. 3 (B) front view of the cross-over head communication assembly.

Fig. 7 is a schematic diagram of a rear measurement nipple.

FIG. 8 is a schematic diagram of a broken soft thin coal seam gas extraction long drilling construction method.

Reference signs mean:

1. a directional drill bit, 2, a front measuring short section, 3, a non-magnetic thread-passing screw drilling tool, 4, a rear measuring short section, and 5, a central cable-passing drill rod; 201. the system comprises a transmission central shaft, 202, a front measurement short section outer pipe 203, a communication joint, 204, a communication cable, 205, a signal transmission unit, 206, a voltage stabilizing unit, 207, an engineering parameter measurement unit, 208 and an azimuth gamma measurement unit; 301. a communication cable assembly 302, a communication short section outer pipe 303, a side wall rotating center communication short section 304, a transmission shaft 305, a universal shaft 306, a screw motor 3061, a stator 3062, a rotor 307, a transmission shaft outer pipe 308, a universal shaft outer pipe 309, a screw motor outer pipe 310, a crossover joint communication assembly 311, an insulating rubber ring I, 312, an insulating rubber ring II, 313, a male slip ring 314, a high-strength spring 315, a female slip ring 316, a crossover joint cable; 401. the method comprises the following steps of arranging an outer pipe of a measuring pup joint at the rear position 402, a signal receiving unit 403, an azimuth measuring unit 404, a signal transmitting unit 405, a centralizer 406 and a fixing ring.

The invention is described in detail below with reference to the drawings and the detailed description.

Detailed Description

The present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention fall within the protection scope of the present invention. The present invention will be described in further detail with reference to examples.

Example 1:

the embodiment provides a directional long borehole construction drilling tool combination is taken out in garrulous soft thin coal seam gas drainage, as shown in fig. 1 to 7, include from the bottom up consecutive directional drill bit 1, leading measurement nipple 2, no magnetism cross line screw rod drilling tool 3, rearmounted measurement nipple 4 and central cable drilling rod 5.

The prepositive measuring short section 2 comprises a transmission central shaft 201 with a central through hole, a prepositive measuring short section outer pipe 202 sleeved outside the transmission central shaft 201 and a communication measuring unit arranged on the prepositive measuring short section outer pipe 202; the nonmagnetic thread-passing 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 turning 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 pipe 401 sleeved outside the central communication measuring unit; the central through cable drill rod 5 comprises a central cable and a drill rod outer tube.

The directional drill bit 1, the transmission central shaft 201 and the central heart force unit are connected in sequence; the front-mounted measuring short section outer pipe 202, the non-magnetic drilling tool outer pipe, the communication short section outer pipe 302, the rear-mounted measuring short section outer pipe 401 and the drill pipe outer pipe are sequentially connected; the communication measuring unit, the communication cable assembly 301, the side wall center-turning communication short section 303, the center communication measuring unit and the center cable are communicated in sequence.

In the scheme, the directional drill bit is provided with a gas one-way stop valve, so that the damage to a preposed measuring nipple and a non-magnetic thread-passing screw drilling tool caused by the backflow of gas carrying hole bottom drilling slag from a drill bit water hole when the pressure in the drill rod is relieved is avoided; the front measuring nipple is used for measuring the drill hole inclination angle at the position close to the drill bit, the tool face angle and the natural gamma radioactivity intensity of the stratum; the non-magnetic wire-passing screw drilling tool is used for providing rock crushing power for the drill bit, conveying the measurement data of the front measurement short section to the rear measurement short section through a side wall communication component of the non-magnetic wire-passing screw drilling tool, and meanwhile serving as a power supply channel of the front measurement short section; the short energy-saving side wall-to-center communication mode converts a transmission channel of a side wall communication assembly of the non-magnetic wire-passing screw drill into a center transmission channel; the rear measuring short section is used for receiving the measuring data of the front measuring short section and measuring the azimuth angle of the drilled hole; the central cable drill rod is used for uploading hole bottom measurement data.

The communication measuring unit is used for measuring the drill hole inclination angle at the position close to the drill bit, the tool face angle and the stratum natural gamma radioactivity intensity; 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 orientation 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 measuring unit 207 and the azimuth gamma measuring unit 208, and the communication joint 203 is arranged at the end part of the front measuring nipple outer pipe 202 and can communicate with the non-magnetic threaded screw drilling tool 3.

The front end of the transmission central shaft 201 is provided with a transmission joint to be connected with the directional drill bit 1, and the transmission central shaft 201 can transmit the power output by the non-magnetic wire-passing screw drill 3 to the directional drill bit 1; the side wall of the transmission center shaft 201 of the embodiment is provided with a through hole, and the through hole can be communicated with the central channel of the transmission center shaft 201 and the annular gap between the transmission center shaft 201 and the front measurement nipple outer tube 202; the inner wall of the outer pipe 202 of the front measuring nipple is provided with a wear-resistant rubber coating.

The central power unit comprises a transmission shaft 304, a cardan shaft 305 and a screw motor 306 which are connected in sequence; the non-magnetic drill outer pipe comprises a transmission shaft outer pipe 307 sleeved outside a transmission shaft 304, a universal shaft outer pipe 308 sleeved outside a universal shaft 305 and a screw motor outer pipe 309 sleeved outside a screw motor 306 which are connected in sequence.

The joint of the front measurement short section outer pipe 202 and the transmission shaft outer pipe 307, the joint of the transmission shaft outer pipe 307 and the universal shaft outer pipe 308, the joint of the universal shaft outer pipe 308 and the screw motor outer pipe 309, and the joint of the screw motor outer pipe 309 and the communication short section outer pipe 302 are all provided with a crossover joint communication assembly 310 so as to form a wired communication transmission channel among the communication measurement unit, the communication cable assembly 301 and the side wall rotation center communication short section 303.

The crossover sub communication assembly 310 comprises two opposite insulating rubber rings, wherein an annular groove I is formed in the insulating rubber ring I311, and an annular groove II is formed in 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 fit contact, and a jumper cable 316 extending out of the two insulating rubber rings is connected to the male slip ring 313 and the female slip ring 315, respectively.

The high-rigidity spring has the effects that the male slip ring is pushed to be in good contact with the female slip ring, meanwhile, when the male slip ring is abraded, the male slip ring is pushed to move, the male slip ring is automatically compensated, stable transmission and stable power supply of measuring signals are achieved, and the insulating rubber ring is fixed through 4 circumferential bolts through the bolt fixing holes in the insulating rubber ring.

Specifically, in a crossover joint communication assembly between the front measurement short section outer pipe and the transmission shaft outer pipe, two insulating rubber rings are respectively installed at the ends of the front measurement short section outer pipe and the transmission shaft outer pipe, and a crossover joint cable of the crossover joint communication assembly can be communicated with communication measurement units and communication cable assemblies at two sides; in a crossover joint communication assembly between the outer pipe of the transmission shaft and the outer pipe of the universal shaft, two insulating rubber rings are respectively arranged at the end parts of the outer pipe of the transmission shaft and the outer pipe of the universal shaft, and a crossover joint cable can be communicated with communication cable assemblies at two sides; in a crossover joint communication assembly between the outer pipe of the universal shaft and the outer pipe of the screw motor, two insulating rubber rings are respectively arranged at the end parts of the outer pipe of the universal shaft and the outer pipe of the screw motor, and a crossover joint cable can be communicated with communication cable assemblies at two sides; in the crossover sub communication subassembly between screw motor outer tube and the communication nipple joint outer tube, two insulating rubber rings are installed respectively at screw motor outer tube and communication nipple joint outer tube tip, and its crossover sub cable can communicate the communication cable subassembly and the lateral wall center of turning communication nipple joint of both sides.

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 inside the stator 3061. The rated torque of the screw motor is more than or equal to 200Nm, the 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 utilizing 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 non-magnetic wire-passing screw drill.

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.

The central communication measuring unit of the rear measuring pup joint 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 drilling azimuth, the signal receiving unit 402 is connected with and can supply power to the sidewall centering communication nipple 303 and can also receive near-bit measurement information transmitted by the front measurement nipple 2, and the signal transmitting unit 404 transmits measurement data in a hole to the orifice through the central cable drill rod 5; the rear-mounted measuring short joint 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.

Example 2:

a directional long drilling construction method for extracting broken soft thin coal seam gas is realized by the construction drilling tool combination of the embodiment 1; the method comprises the following steps:

designing a drilling track 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 revealed 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 to ensure that the drilling track extends in the thin coal seam;

the method comprises the following steps: borehole trajectory parameters and formation natural gamma radioactivity measurements: in the drilling process, a process parameter measuring unit in a front measuring short section is used for measuring the drilling inclination angle of a hole section at the position close to a drill bit and the tool face angle, and the change condition of a drilling track in the vertical direction is obtained; the method comprises the steps that an azimuth gamma measuring unit in a front measuring nipple is used for measuring the natural gamma radioactivity intensity of a stratum at a position close to a drill bit, 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, a rear measuring nipple is used for measuring the azimuth angle of a drilled hole, and the change condition of a drilling track in the horizontal direction is obtained;

step two: real-time transmission of measurement data: the dip angle, the azimuth angle, the tool orientation angle and the stratum natural gamma radioactive intensity data of the drill hole are coded by using a rear-mounted measuring short-section signal transmitting unit and are uploaded to an orifice explosion-proof computer through a central cable drill rod;

step three: processing and inverting the measured data: the method comprises the steps of identifying the lithology of the stratum and the interface of the coal rock stratum by utilizing the collected natural gamma radioactivity intensity of the stratum, accurately positioning the position of a directional drill bit by combining the collected drill hole inclination angle, azimuth angle and hole depth relation, determining the vertical distance between the directional drill bit and the interface of the coal rock stratum, predicting the included angle between the extension direction of the drill bit and the interface of the coal rock stratum, further reversing the characteristics of space distribution of a top floor rock stratum, thickness change of a thin coal layer and the like, updating an initial three-dimensional geological model, and establishing a three-dimensional dynamic geological model.

And (3) geosteering drilling: correcting a drilling design track in real time based on the three-dimensional dynamic geological model, and adjusting the design track to extend along the actually detected thin coal seam; and controlling the non-magnetic thread-passing screw drill to perform guide drilling according to the corrected design track until the design hole depth is reached.

And (5) slicing is carried out in the three-dimensional dynamic geological model along the main design direction of the drill hole to obtain a two-dimensional section diagram of the drill hole track, 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-rock layer interface and the included angle between the extension direction of the drill bit and the coal-rock layer interface obtained in the step four, and a certain safety distance is reserved for the adjustment of the direction of the drill bit.

In the drilling process, when the lower gamma value of the stratum measured by the front measuring nipple is increased firstly and the upper gamma value is increased later, the drill bit is judged to approach the bottom plate rock stratum, and the drilling inclination angle needs to be increased; when the measured gamma value on the stratum is increased firstly and the measured gamma value is increased after the measured gamma value is decreased, judging that the direction of the drill bit approaches to a roof stratum and the inclination angle of a drill hole needs to be decreased;

and calculating the distance of the directional drill bit out of the thin coal seam in the drilling direction by the following formula:

L＝D/sinα-L_a

L_b＝Lsinα

in the formula: d is the vertical distance between the azimuth gamma measuring unit and the coal-rock interface; l is_aThe distance between the azimuth gamma measuring unit and the directional drill bit; alpha is an included angle between the coal rock interface and the front measuring short joint; l is the distance of the directional drill bit in the drilling direction to drill the thin coal seam; l is_bThe vertical distance from the directional drill bit to the coal-rock interface in the drilling direction.