An automatic orifice anti-blowout device with multi-parameter linkage for a directional drilling rig and its anti-blowout method

Abstract

The present invention relates to a multi-parameter linkage orifice automatic blowout prevention device for a directional drill and a blowout prevention method thereof, which includes a hollow fixed casing for inserting into a coal body and a directional drill passing through the fixed casing. A methane probe and a flow probe are installed on the inner wall of the front end of the fixed casing. A blowout prevention valve is sleeved on the middle and rear sections of the fixed casing. A microprocessor signal-connected to the directional drill, the methane probe and the flow probe is arranged outside the directional drill. The microprocessor is signal-connected to the blowout prevention valve. A pressure relief pipe connected to a gas-slag separation device is installed on the fixed casing; it solves the problems in the prior art that during the construction of gas drainage boreholes, the roadway gas exceeds the limit due to blowout, and coal, gas and water ejected from the front are extremely likely to harm the operators.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine safety, and relates to a multi-parameter linkage orifice automatic anti-blowout device for a directional drill and an anti-blowout method thereof. Background Art

[0002] Coal mine gas accidents are engineering accidents that often occur in high-gas and outburst mines. At present, gas control mainly relies on constructing drainage boreholes. Due to factors such as high pressure, high in-situ stress, and soft coal quality in the gas drainage boreholes, borehole outburst accidents are likely to occur. There are two common types of borehole outbursts: ① Borehole blowout. It refers to the continuous ejection of gas and pulverized coal from the borehole within a very short time during or after the construction of a coal seam drainage borehole. The outburst occurs at the coal head in front of the construction borehole. After the outburst, the shape of the borehole basically remains intact. This type of outburst can be called "borehole blowout". Although the intensity of this type of outburst accident is not too large, the duration is relatively long, and generally it will not cause very serious consequences. ② Face outburst induced by drilling. It refers to an outburst accident that occurs when the coal wall of the face at the drilling site is damaged due to the vibration generated during the drilling construction process or due to the induction of borehole blowout. In this type of outburst accident, the outburst point cannot be accurately determined, and its outburst intensity is relatively large and sudden. According to relevant statistical data, more than 90% of borehole outburst events belong to borehole blowout, and there will be multiple blowouts during the borehole construction process, resulting in the gas volume fraction exceeding the limit near the working area, which not only affects the construction progress but also may endanger the personal safety of on-site operators (Hao Xiuming, Li Zhong. Anti-blowout orifice device for gas drainage borehole construction. Energy Technology and Management, Vol. 42, No. 5, 2017, pp. 32 - 33).

[0003] In order to improve the construction efficiency of drainage boreholes, prevent abnormal gas during drilling, and ensure the safe operation of borehole construction, an anti-blowout device must be installed at the orifice. At present, the construction equipment for coal mine gas drainage boreholes is mainly divided into ordinary drills and directional drills. The construction depth of ordinary drills is generally 100 - 180m, and the construction depth of directional drills is generally more than 300m.

[0004] There are already various designs of borehole blowout prevention devices for conventional drilling in China. Basically, they are all composed of an orifice collector, a gas-slag separation device, and a gas drainage device. For example, the new blowout prevention device made by Gong Dayin and Zhang Zhenbin finally formed a "ring-shaped double-loop double-negative pressure" pumping after three-phase updates, using two independent boxes to control "gas, water, and coal" respectively. Whether at the operation site or in the return air current of the roadway on the downwind side of the operation location, the gas fluctuation range is not large, generally fluctuating between 0.12% and 0.24%, indicating that the blowout prevention device has played a role (Gong Dayin, Zhang Zhenbin. Research and Application of a New Blowout Prevention Device in Gucheng Coal Mine. Coal and Chemical Industry, Vol. 42, No. 3, March 2019, pp. 100-102). The device made by Hao Xiuming and Li Zhong mainly consists of four parts: an orifice multi-way device, a gas-water separation device, a coal storage device, and a hole-fixing pipe. According to the on-site application effect, when the gas pressure of the coal seam at the construction site is lower than 2 MPa, the effect is particularly obvious (Hao Xiuming, Li Zhong. Blowout Prevention Orifice Device for Gas Drainage Borehole Construction. Energy Technology and Management, Vol. 42, No. 5, 2017, pp. 32-33). Zhang Jizhou, Li Jianfeng, and Xu Hongliang's double blowout prevention barriers can effectively block the harm of coal slag ejected from the borehole to personnel, and at the same time serve as a gas storage space during blowout (with a volume of 20-26 m 3 ). In addition, continuous drainage of the gas in the barrier (flow rate 40 m 3 / min) can prevent the gas ejected from the hole from concentrating and gushing into the roadway (Zhang Jizhou, Li Jianfeng, Xu Hongliang. Gas Blowout Prevention and Control Technology for Deep High Geostress Outburst Coal Seams. Coal Engineering, No. 5, 2016, pp. 62-64).

[0005] There are also designs of borehole blowout prevention devices for directional drilling rigs in China. For example, the blowout prevention device for kilometer borehole drilling designed and made by Wang Guofei. The main components of this device include a hole-sealing casing, an orifice multi-way device, a gas-coal separation device, a blowout prevention drainage pipe, and a three-way slag discharge device. During the borehole construction process, a large amount of coal, gas, and water gushing out pass through the orifice multi-way device. Most of the ejected coal slag and water enter the three-way slag discharge device, and a small amount of coal slag and gas are sucked into the gas-coal separation device through the drainage hose. In the gas-coal separation device, the water, coal slag, and gas are separated. The coal slag is discharged through the slag discharge port of the gas-coal separation device, and the gas enters the drainage pipeline through the blowout prevention drainage pipe. During the borehole construction process, the gas concentration in the drill yard has always remained stable, which can solve most of the gas overrun accidents caused by blowout, minimize the impact of blowout on production, and improve the efficiency of directional drilling rig borehole construction (Wang Guofei. Application of Blowout Prevention Device for Kilometer Borehole Drilling in Gas Drainage of Shuangliu Coal Mine. Energy and Environmental Protection, April 2018, pp. 37-43).

[0006] Although the above several blowout prevention devices can solve some problems related to blowout, due to the limitations of design and manufacture, they do not have the functions of risk avoidance and linkage. Summary of the Invention

[0007] In view of this, the present invention provides a multi-parameter linkage orifice automatic anti-blowout device for a directional drill and an anti-blowout method thereof to solve the problems in the prior art that when constructing a gas drainage borehole, the roadway gas exceeds the limit due to blowout, and the coal, gas and water ejected from the front are extremely likely to harm the operators.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A multi-parameter linkage orifice automatic anti-blowout device for a directional drill includes a hollow fixed casing for inserting into the coal body and a directional drill passing through the fixed casing. A methane probe and a flow probe are installed on the inner wall of the front end of the fixed casing. A blowout prevention valve is sleeved on the middle and rear sections of the fixed casing. A microprocessor is arranged outside the directional drill and is signal-connected to the directional drill, the methane probe and the flow probe. The microprocessor is signal-connected to the blowout prevention valve. A pressure relief pipe connected to a gas and slag separation device is installed on the fixed casing.

[0010] Advantages of this basic solution: A valve plate and a pipe communicating with the roadway are installed on the blowout prevention valve in the middle and rear parts of the fixed casing, which can transfer the ejected solid-liquid-gas mixture to the roadway beside the borehole to prevent injury from ejecting from the front of the borehole orifice. A data processor, also called a microprocessor, connected to the directional drill is installed at the rear end of the fixed casing. The microprocessor can collect the methane probe, the flow velocity probe, the feeding pressure and the rotation torque of the directional drill, analyze these four data, and judge the action of the blowout prevention valve.

[0011] Further, a fixing agent is filled between the fixed casing and the coal body.

[0012] Further, the fixing agent is high-strength cement.

[0013] Further, the microprocessor is used to receive the pressure data fed by the directional drill and the bit torque data.

[0014] Further, the blowout prevention valve is fixedly connected to the fixed casing and fixed in the coal body by a fixing agent.

[0015] The anti-blowout method of the multi-parameter linkage orifice automatic anti-blowout device for the directional drill includes the following steps:

[0016] A. Ream the borehole of the 18 m part of the orifice of the borehole to be constructed with the bit at the front end of the drill pipe of the directional drill so that the fixed casing can be sealed into the reamed section of the borehole;

[0017] B. Inject cement between the hole wall of the reamed section and the outer wall of the fixed casing to bond the fixed casing and the coal body into one body;

[0018] C. A methane detector and a flow detector are installed on the inner wall of the front end of the fixed casing. A blowout preventer valve is sleeved on the middle and rear orifice ends of the fixed casing. The methane detector and the flow detector are connected to a microprocessor outside the orifice through data lines. At the same time, the microprocessor also collects data on the feed pressure and torque of the directional drill;

[0019] D. Analyze these four data to determine whether a blowout is about to occur in the borehole;

[0020] E. If it is determined that a blowout is about to occur, the microprocessor issues an instruction to the actuating mechanism of the blowout preventer valve. The blowout preventer valve closes the orifice, and the ejected coal-water-gas mixture is guided through a pressure relief pipe to a gas-slag separation device outside the orifice. The gas-slag separation device is connected to the gas drainage pipeline to ensure that the gas does not overflow into the roadway.

[0021] Furthermore, the blowout preventer valve is located 1 m away from the orifice at the orifice end of the fixed casing.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. For the multi-parameter linkage orifice automatic blowout prevention device of the directional drill disclosed by the present invention, the blowout preventer valve is integrated with the fixed casing and is located 1 m away from the orifice at the orifice end of the casing. The fixed casing and the coal body in the 18 m reamed section of the orifice are firmly fixed together by a cement fixing agent. Different from other blowout prevention devices, this design can prevent the coal-water-gas mixture ejected during a serious blowout from damaging the blowout prevention device outside the orifice and injuring people. In the automatic blowout prevention device, the designed blowout preventer valve and the fixed casing are fixed together, and the blowout preventer valve and the fixed casing are firmly fixed in the coal body by a cement fixing agent. Although the ejected mixture has a great impact on the blowout preventer valve, since the blowout preventer valve is fixed in the coal body, it will not fall off and injure people, ensuring the safety of construction personnel and the non-exceedance of roadway gas. The automatic blowout prevention device simultaneously receives data from the methane detector, the flow detector, the feed pressure data of the directional drill, and the bit torque data by the microprocessor, and determines whether the blowout preventer valve operates by analyzing these four data, effectively solving the passivity existing in the existing blowout prevention devices.

[0024] 2. For the multi-parameter linkage orifice automatic blowout prevention device of the directional drill disclosed by the present invention, the designed blowout preventer valve is located inside the orifice, which is convenient for construction personnel to observe the real-time slag discharge situation during drilling at the orifice; it is also convenient for construction personnel to adopt appropriate drilling operation techniques to reduce the probability of blowout by observing the data of the microprocessor outside the directional drill; when a blowout occurs, the blowout preventer valve closes, and the ejected mixture sprays out from the pressure relief pipe beside the orifice, without injuring the construction personnel at the orifice, ensuring the personal safety of construction personnel.

[0025] Other advantages, objects, and features of the present invention will, to some extent, be set forth in the following description, and to some extent, will be obvious to those skilled in the art based on an examination of the following text, or can be learned from the practice of the present invention. The objects and other advantages of the present invention can be achieved and obtained through the following description. Brief Description of the Drawings

[0026] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0027] Figure 1 It is a schematic structural diagram of the multi-parameter linkage orifice automatic blowout prevention device of the directional drilling rig of the present invention.

[0028] Reference numerals: coal body 1, pressure relief pipe 2, directional drilling rig 3, microprocessor 4, blowout prevention valve 5, cement 6, fixed casing 7, methane probe 8, flow probe 9, borehole 10, drill pipe 11, drill bit 12. Detailed Embodiments

[0029] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0030] Among them, the accompanying drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation on the present invention; in order to better illustrate the embodiments of the present invention, some components in the accompanying drawings will be omitted, enlarged, or reduced, and do not represent the dimensions of actual products; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0031] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and cannot be understood as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] As Figure 1 shown, the multi-parameter linkage orifice automatic anti-blowout device of the directional drill rig includes a hollow fixed casing 7 for inserting into the coal body 1 and a directional drill rig 3 inserted into the fixed casing. A methane probe 8 and a flow probe 9 are installed on the inner wall of the front end of the fixed casing 7. A blowout prevention valve 5 is sleeved on the middle and rear sections of the fixed casing 7. The blowout prevention valve 5 is fixedly connected to the fixed casing 7 and fixed in the coal body 1 by cement 6. A pressure relief pipe 2 connected to a gas-slag separation device is installed on the fixed casing 7.

[0033] The 18m part of the orifice is reamed with a reaming bit so that the fixed casing 7 can be sealed into the reamed section of the borehole. The multi-parameter linkage orifice automatic anti-blowout device of the directional drill rig includes a methane probe 8 and a flow probe 9 installed at the front end of the fixed casing 7. A blowout prevention valve 5 is installed at the orifice end of the middle and rear parts of the fixed casing 7. Cement 6 is injected between the hole wall of the reamed section and the outer wall of the fixed casing 7 to bond the fixed casing 7 and the coal body 1 into one body. The two probes, the methane probe 8 and the flow probe 9, are connected to the microprocessor 4 outside the hole through data lines. At the same time, the microprocessor 4 also collects data on the feed pressure and torque of the directional drill rig 3. By analyzing these four data, it is judged whether a blowout will occur in the borehole; if it is judged that a blowout will occur, the microprocessor 4 issues an instruction to the actuating mechanism of the blowout prevention valve 5, and the blowout prevention valve 5 closes the orifice, guiding the ejected coal-water-gas mixture to the gas-slag separation device outside the hole. The gas-slag separation device is connected to the extraction pipeline to ensure that the gas does not overflow into the roadway. The volume of the gas-slag separation device is made according to the volume calculated by the ejected coal volume calculation model.

[0034] The multi-parameter linkage orifice automatic blowout prevention device for the directional drilling rig. The microprocessor simultaneously collects the water flow rate in the borehole, gas concentration, the feed pressure of the drilling rig, and the bit torque. The orifice part of the fixing device is provided with a blowout prevention valve linked to the microprocessor, which will automatically close or open the orifice upon receiving the instruction from the microprocessor. When closing, to prevent excessive blowout pressure from destroying the orifice device, a pressure relief channel is provided inside the blowout prevention valve. When the pressure reaches a certain threshold, the pressure relief channel is opened, and an appropriate amount of coal and gas are discharged through the pressure relief pipe into the pressure relief container to control the gas in the roadway not to exceed the limit.

[0035] This automatic blowout prevention device is for the directional drilling rig. It can not only achieve the functions of the existing devices in the background technology but also realize the functions of risk avoidance and linkage. The so-called risk avoidance means that when the blowout intensity is relatively large, the ejected matter can push the manual blowout prevention device out of the borehole. At this time, the ejected coal, gas, and water spraying out from the front are extremely likely to harm the operators. The present invention adopts an embedded blowout prevention valve. When this device operates, the ejected matter can be discharged from the pressure relief pipe beside the borehole to the gas and slag separator. Its linkage function is a systematic action that determines whether the blowout prevention valve operates by analyzing whether the data of the methane and water flow rates, the feed force of the directional drilling rig, and the bit torque are abnormal.

[0036] The blowout prevention method of the multi-parameter linkage orifice automatic blowout prevention device for the directional drilling rig includes the following steps:

[0037] A. For the 18m part of the orifice of the borehole to be constructed, use the bit 12 at the front end of the drill pipe 11 in the directional drilling rig 3 to drill and ream the borehole 10 so that the fixed casing 7 can be sealed into the reamed section of the borehole;

[0038] B. Inject cement 6 between the hole wall of the reamed section and the outer wall of the fixed casing 7 to bond the fixed casing 7 and the coal body 1 into one body;

[0039] C. Install a methane probe 8 and a flow probe 9 on the inner wall of the front end of the fixed casing 7. A blowout prevention valve 5 is sleeved on the middle and rear orifice ends of the fixed casing 7. The methane probe 8 and the flow probe 9 are connected to the microprocessor 4 outside the hole through data lines. At the same time, the microprocessor 4 also collects the data of the feed pressure and torque of the directional drilling rig;

[0040] D. Judge whether a blowout is about to occur in the borehole by analyzing these four data;

[0041] E. If it is judged that a blowout is about to occur, the microprocessor 4 sends an instruction to the actuator of the blowout prevention valve 5, and the blowout prevention valve 5 closes the orifice, guiding the ejected coal-water-gas mixture through the pressure relief pipe 2 to the gas and slag separation device outside the hole. This gas and slag separation device is connected to the extraction pipeline to ensure that the gas does not overflow into the roadway.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An automatic orifice anti-blowout device with multi-parameter linkage for a directional drilling rig, characterized in that, It includes a hollow fixed casing for inserting into the coal body and a directional drill rig inserted into the fixed casing. A methane probe and a flow probe are installed on the inner wall of the front end of the fixed casing. A blowout preventer valve is sleeved on the middle and rear sections of the fixed casing. A microprocessor is arranged outside the directional drill rig and is signal-connected to the directional drill rig, the methane probe, and the flow probe. The microprocessor is signal-connected to the blowout preventer valve. A pressure relief pipe connected to a gas-slag separation device is installed on the fixed casing; Fixing agent is filled between the fixed casing and the coal body; The blowout preventer valve is fixedly connected to the fixed casing and is fixed in the coal body through the fixing agent.

2. The multi-parameter linkage orifice automatic blowout prevention device for a directional drilling rig according to claim 1, characterized in that, The fixing agent is high-strength cement.

3. The multi-parameter linkage orifice automatic blowout prevention device for a directional drilling rig according to claim 1, characterized in that, The microprocessor is used to receive the pressure data and the bit torque data fed by the directional drill rig.

4. The blowout prevention method of the multi-parameter linkage orifice automatic blowout prevention device for the directional drilling rig according to claim 1, characterized in that, It includes the following steps: A. Use the bit at the front end of the drill pipe of the directional drill rig to drill and ream the 18 m part of the orifice of the borehole to be constructed, so that the fixed casing can be sealed into the reamed section of the borehole; B. Inject cement between the hole wall of the reamed section and the outer wall of the fixed casing to bond the fixed casing and the coal body into one body; C. Install a methane probe and a flow probe on the inner wall of the front end of the fixed casing. A blowout preventer valve is sleeved on the middle and rear orifice ends of the fixed casing. The methane probe and the flow probe are connected to the microprocessor outside the hole through data lines. At the same time, the microprocessor also collects the data of the feed pressure and torque of the directional drill rig; D. Judge whether a blowout is about to occur in the borehole by analyzing these four data; E. If it is judged that a blowout is about to occur, the microprocessor sends an instruction to the actuating mechanism of the blowout preventer valve. The blowout preventer valve closes the orifice, and guides the ejected coal-water-gas mixture to the gas-slag separation device outside the hole. The gas-slag separation device is connected to the extraction pipeline to ensure that the gas does not overflow into the roadway.

5. The blowout prevention method of the multi-parameter linkage orifice automatic blowout prevention device for a directional drilling rig according to claim 4, characterized in that, The blowout preventer valve is located 1 m away from the orifice at the orifice end of the fixed casing.

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