China University of Mining and Technology (CUMT)

Xuzhou Boan Science & Technology Development Co., Ltd

Baiquan Lin

Wei Yang

Ting Liu

Chuanjie Zhu

Hao Yao

Fazhi Yan

Chang Guo

Quanle Zou

Jia Kong

Qingzhao Li

Yidu Hong

Rui Wang

He Li

Tong Liu

Yang Zhao

Minghua Lin

Ru Jia

Changzheng Lu

Yidou Hong

Zheng Wang

Cheng Zhai

Zhanbo Huang

Yihan Wang

Zishan Gao

Ximiao Lu

A method for extracting gas by fracturing a coal seam through a combination of hydraulic slotting and multi-stage combustion impact wave comprises cutting slots in an impact borehole using a hydraulic slotting equipment to perform pressure relief and permeability enhancement on a coal seam and enlarge a N(nitrogen gas) or CO(carbon dioxide gas) storage space, injecting a large amount of Nor COinto the borehole by means of a high pressure gas cylinder and a pressure reducing valve through a gas injection and extraction pipe, then injecting a certain amount of methane and dry air into a high-temperature and high-pressure combustion chamber by means of the high pressure gas cylinder and the pressure reducing valve, so that the gases are mixed and combusted to form high-temperature and high-pressure impact wave to push a piston to compress the Nor CO, thereby generating a large number of factures on the coal seam around the impact borehole under guiding action of the slots. The impact wave is repeatedly generated to form a multi-stage impact, and the impact of the next stage is based on the impact of the previous stage, so that the fractures on the coal seam around the borehole are further expanded and run through. After the Nor COis compressed by means of the multi-stage impact, more fracture networks are formed on the coal seam around the borehole under the guiding action of the slots and the fractures, thereby enhancing the borehole-based efficient gas extraction.

Method for extracting gas by fracturing coal seam through combination of hydraulic slotting and multi-stage combustion impact wave

In a method, a gyroscope and an endoscopic camera are first used to investigate coal-seam strike trend, coal-seam dip trend, and coal-seam thickness data of a to-be-extracted area. According to gas extraction standard requirements of a to-be-extracted area, boreholes are then designed and constructed, and trajectories of boreholes are tracked to obtain a correspondence relationship between designed borehole parameters and actual borehole trajectory parameters. Next, drilling parameters are adjusted according to the correspondence relationship between the designed borehole parameters and the actual borehole parameters to construct boreholes at predetermined borehole locations. Subsequently, the boreholes are connected to an extraction pipeline, and gas extraction flow rates and gas extraction amounts per meter of the boreholes are observed. Eventually, other boreholes are designed and constructed according to the adjusted borehole construction parameters and extraction data. After being constructed, the boreholes are connected to perform gas extraction.

Method for precisely extracting coal-mine gas

A dust suction hood includes a tapered outer cover, a cylindrical outer cover, a tapered inner baffle plate disposed in the tapered outer cover, and a first blocking member matched with an opening in the other end of the cylindrical outer cover. A top opening of the tapered outer cover is matched with an opening in one end of the cylindrical outer cover. A side wall opening of the cylindrical outer cover serves as a dust outlet. A first gap is formed in the tapered outer cover. A first dust suction port is formed between bottom openings of the tapered inner baffle plate and the tapered outer cover. A first drill pipe connecting port is formed in the first blocking member. A drill pipe of the mine drill passes through the first drill pipe connecting port to penetrate the dust suction hood on the drill pipe.

Mine drill, dust suction hood and dust removal device thereof

An integrated hole sealing, device includes a capsule plug, an outer capsule having a first hole site, an inner capsule having a second hole site, a capsule water injection pipe, a borehole water injection pipe and a tapered plug. Two ends of the outer capsule and the inner capsule are respectively fixed on the capsule plug and the tapered plug. The capsule plug, the tapered plug, the outer capsule and the inner capsule form a closed hollow cylindrical cavity. A middle part of the inner capsule is a hollow pipeline, and two ends thereof respectively correspond to the first and second hole sites. The borehole water injection pipe passes through the hollow cylindrical cavity. A part, located in the hollow cylindrical cavity, of the borehole water injection pipe is telescopically wound outside the inner capsule. The capsule water injection pipe passes through the capsule plug and extends into the hollow cylindrical cavity.

Integrated hole sealing device for loosening blasting and water injection of underground deep hole

A multi-stage combustion impact wave coal mass cracking and heat injection alternating intensified gas extracting method is provided. A large amount of Nor COis injected into a drill hole by a heat injection and gas injection extracting pipe and by a high-pressure gas cylinder and a reducing valve, then a certain amount of methane and dry air are injected into a high-temperature and high-pressure combustion chamber by the high-pressure gas cylinder and the reducing valve, to be mixed and combusted to form high-temperature and high-pressure impact wave. High-temperature vapour is injected into the drill holes by the heat injection and gas injection extracting pipe to promote desorption of the coal masses.

Multi-stage combustion impact wave coal mass cracking and heat injection alternating intensified gas extracting method

A method for constructing networked preferential gas migration pathways and diverting and extracting gas. The method proposes that a fracture generation hole, a fracture guidance and development hole, a lateral rupture hole, and a fracture connection hole are respectively constructed in a roof in roadways on two sides of a working face in advance of an advance stress change area. Artificial guided fractures are actively constructed and formed inside the hard roof. Under a mining-induced stress effect, the artificial guided fractures and mining-induced fractures intersect with and are connected to each other to form networked preferential gas migration pathways. Meanwhile, boreholes for artificial guided fractures accelerate roof fracturing to form a rupture bed separation fracture area in a roof. Gas flows and migrates in a timely and efficient manner along networked fracture pathways and concentrates in the rupture bed separation fracture area in the roof.

Method for constructing networked preferential gas migration pathways and diverting and extracting gas

A method for stepwise construction of a preferential gas migration pathway at a stope in a coal seam. First, a gas migration pathway is preliminarily formed at a stope depending on a mining effect of mining in a first mined seam. construction and stabilization method of gob-side entry retaining in deep strata, and a method of manual-guided pre-fracturing boreholes are then used to perform active construction respectively in external space and the outside of coal-rock mass to form preferential gas migration pathways. Eventually, under the effect of mining-induced stress, a system of preferential gas migration pathways connected to each other at the stope is further formed.

Method for stepwise construction of preferential gas migration pathway at stope in coal seam

A gas extraction method in which high energy gas fracturing technology is used to form a fracture network in a thermal injection borehole. Then high-pressure, cyclically temperature-changing steam is injected into the borehole using a spinning oscillating-pulse jet nozzle to form oscillating superheated steam, alternatingly impacting and heating the coal body. The high energy gas forms a fracture network that provides channels for passage of the superheated steam, while oscillating changes in steam temperature and pressure also promote crack propagation and perforation of the coal body; the combined effect of alternation of the two enhances gas desorption and extraction efficiency.

Method for gas extraction alternating oscillating pulse high energy gas extraction with thermal injection

A method for combining integrated drilling, flushing and slotting with thermal injection to enhance coalbed gas extraction, applicable to managing gas extraction from microporous, low-permeability, high-adsorption coalbed areas. A gas extraction borehole is drilled within a certain distance of a predetermined drilling, flushing and slotting borehole, and, once sealed, is used for gas extraction. An integrated drilling, flushing and slotting drill bit is used to sink the borehole, which is then sealed. Concentration variation in the gas extraction borehole is monitored in real time, and when concentration is below 30%, borehole is opened and high-temperature steam is injected by means of a steam generator, after which the borehole is again closed. Drilling a drilling, flushing and slotting borehole increases pressure relief space and the surface of exposed coal, relieves stress on the coal body, and increases gas permeability of the coalbed, while the injection of high-temperature steam promotes gas desorption in the coal body, promotes crack propagation around the borehole, and increases channels for gas flow, thus achieving highly efficient extraction of gas from the coalbed.

Method for integrated drilling, flushing, slotting and thermal injection for coalbed gas extraction

A method for combining integrated drilling and slotting with oscillating thermal injection to enhance coalbed gas extraction, applicable to managing gas extraction from microporous, low-permeability, high-adsorption coal seam areas. A number of slots are formed within a thermal injection/extraction borehole by means of integrated drilling and slotting technology; a steam generator, is then used to three high-pressure, cyclically temperature-changing steam into said borehole; the steam passing through a spinning, oscillating-pulse jet nozzle forms an oscillating superheated steam, heating the coal body. The present method overcomes the limitations of simple permeability-increasing techniques, the slotting by means of hydraulic. pressure significantly increasing the pressure relief range of a single borehole and forming a fracture network that provides channels for passage of the superheated steam, while oscillating variation in steam temperature and pressure also promote crack propagation and perforation of the coal body; the combined effect of the two enhances the efficiency of gas desorption and extraction.

Method for integrated drilling, slotting and oscillating thermal injection for coal seam gas extraction

Disclosed is a self-regenerative integrated device for the synergetic oxidation of low-concentration gas and ventilation gas in a coal mine. The integrated device comprises a metal shell (). A honeycomb ceramic oxidation bed () is arranged within the metal shell () and divided into a regenerative section () and an oxidation section () by a heat exchange chamber (). A first cavity between the regenerative section () and the inner wall of the metal shell () is divided into a first inlet chamber () and an exhaust chamber () by an inlet partition plate (), a second cavity between the oxidation section () and the inner wall of the metal shell () is divided into a second inlet chamber () and a mixing chamber () by a partition plate () for averaging gas, and a plurality of gas nozzles () are provided on the partition plate () for averaging gas. An internal heat exchanger () is arranged within the heat exchange chamber (), and a heat exchanger inlet () and a heat exchanger outlet () of the internal heat exchanger () are respectively connected with a boiler drum (). The first inlet chamber () is connected with an inlet () of the ventilation gas through a proportional control valve (), the second inlet chamber () is connected with an inlet () for extracting the low-concentration gas through a proportional mixer (), and the proportional control valve () is connected with the proportional mixer () through a connecting pipeline (). The two ends of an inlet preheating pipe () on the honeycomb ceramic oxidation bed () are respectively communicated with the first inlet chamber () and the mixing chamber ().

Self-regenerative integrated device for synergetic oxidation of low-concentration gas and ventilation gas in coal mine

A method for permeability improvement for a downhole coal seam by directional fracturing with pulsed detonation waves, which is applicable to gas control in coal seam areas with high gas concentration and low air permeability. The permeability improvement method is as follows: first, drilling a pulsed detonation borehole and pulsed detonation guide boreholes from a coal roadway to a coal seam respectively; then, pushing a positive electrode connected to a positive output side of an explosion-proof high-voltage electrical pulse generator to the bottom of the pulsed detonation borehole and pushing a negative electrode connected to a negative output side of the explosion-proof high-voltage electrical pulse generator to the bottom of the pulsed detonation guide borehole; connecting the pulsed detonation borehole and the pulsed detonation guide boreholes to an extraction pipeline for gas extraction, after electrical pulsed detonation fracturing for the coal seam is carried out. The method disclosed in the present invention utilizes the high instantaneous energy provided by electrical pulsed detonation waves to fracture a coal mass, so as to form a fissure network in the coal mass between the pulsed detonation borehole and the pulsed detonation guide boreholes; thus, the air permeability coefficient of the coal mass can be increased by 200-400 times, the effective influence scope of gas extraction of a single borehole for gas extraction can be enlarged by 3-4 times, the extracted gas volume from the borehole can be increased by 3-8 times, and the coal seam gas pre-extraction time can be shortened effectively.

Downhole coal seam pulse detonation wave directional fracturing permeability-increasing method

A method for thermal-displacement-type strengthened extraction in a drill hole, suitable for efficient gas extraction in a coal mine, the method comprising the following steps: arranging an extraction drill hole and a thermal displacement drill hole at intervals in a coal seam; continuously heating coal in the drill hole to form a stable temperature field by using a heat pipe; and significantly reducing gas adsorption potential by utilizing a heat effect, prompting gas desorption, and strengthening gas extraction. The method enlarges a range of effective pressure relief influence of a single hole, increases an extraction efficiency of gas in a coal seam by more than 40%, is safe, reliable and low-cost, and is easy to operate, saving both time and labor.

Method for thermal-displacement-type strengthened extraction in drill hole

A distributed combined cooling, heating and power energy system for gas extraction in a coal mining area, which belongs to an energy system for gas production. A gas extraction pump station, a gas storage tank, a water-sealing flame arrester, a wire mesh filter, a first pipeline flame arrester, a wet-type bleeding valve and a cyclone dehydrator are sequentially connected; an outlet of the cyclone dehydrator is divided into two branches, one branch sequentially connected with a second pipeline flame arrester, a proportioning mixer, a gas power machine, a waste heat boiler and a waste heat-type double-effect lithium bromide absorption water chiller/heater unit, and the other connected with a gas-type double-effect lithium bromide absorption water chiller/heater unit; a first power generator is connected with the gas power machine, a water storage tank outlet is connected with a pressurizing pump, a second power generator is connected with a steam turbine and driven by the steam power machine to generate power, and cold/hot water of the waste heat-type water chiller/heater unit and the gas-type water chiller/heater unit is delivered through an energy supply pipeline after collection and mixing. With the power energy system mining area, clean production and utilization of coal-mine gas and economic development of coal mine areas are realized.

Mine area distributed combined cooling heating power energy system for extracting gas for coal mine

Disclosed in the invention is a multi-information coupling prediction method of coal and gas outburst danger, which is achieved by establishing a multi-index coupling prediction model to detect indexes including original gas pressure of a coal layer, the original rock stress, the critical burst gas pressure of a coal sample, the mechanical performance of coal body, the exploit influence, the drilling cutting gas desorption index, the drilling cutting quantity index and the like, therefore to coupling predict the coal and gas outburst danger. By the multi-information coupling prediction method, the information of the coal and gas outburst danger can be fully complemented; the gas and crustal stress outburst danger prediction is carried out; the defects of insufficient complementation information of a single-index and inaccurate prediction are overcome; and the accuracy of the coal and gas outburst danger prediction is improved.

Growing community of inventors

Jiangsu, China

Baiquan Lin