Gas drainage system and method for hyposmosis soft coal seams

The invention discloses a gas drainage system for hyposmosis soft coal seams, which comprises a power device mechanism, a drilling-pressing-pumping integrated mechanism, and a metering mechanism. The power device mechanism comprises an air compressor and an air drilling machine; the drilling-pressing-pumping integrated mechanism comprises a rotary blowout preventer, a boosting pipeline, a drill pipe, a multiple-completion packer, an inner drill pipe connector, a power motor, an electromotor, and an auto-reducing and reaming triple-wing drill bit. The air compressor is sealed and communicated with the inner drill pipe through a high pressure hose; moreover, a control valve, a flowmeter and a pressure meter are arranged on the high pressure hose. The invention also discloses a method using the system to pump gas. The system not only can be used for drilling to make up the difficulty of inconvenient transformation of the gravitation of the soft coal seams, but also can timely implement pressing ...

Loose blasting gas extraction technology of horizontal branch well of coal seam floor

The invention provides a loose blasting gas extraction method of a horizontal branch well of a coal seam floor. The method sequentially comprises the following steps of selecting a coal reservoir with a gas content of more than 8m3/t and a solid coefficient f of less than 0.5; selecting 1-2 m coal seam floor as a layer of a main horizontal well and a branch horizontal well; determining positions of a ground well mouth and a deflection point according to the layer of the main horizontal well section; using a trisected structure as a well body structure and using open hole wells as the main horizontal well and the branch horizontal well; constructing the main horizontal well and the branch horizontal well in a selected floor rock layer; placing explosive points on the branch horizontal well section, wherein the explosive points are connected with each other by lines; and detonating all explosives through the ground; and mounting gas extraction equipment to extract the gas on the ground, wherein ...

Gas drainage system and method for hyposmosis soft coal seams

Method for surface modification and transmission increase of coal reservoirs by using chlorine dioxide

The invention relates to a method for surface modification and transmission increase of coal reservoirs by using chlorine dioxide. The method sequentially comprises the following steps of: (1) selecting the proportioning concentration of the chlorine dioxide according to a coal step and a laboratory experiment; (2) selecting a ground coalbed methane well or an underground drill hole for hydraulic fracturing reservoir modification; (3) pumping chlorine dioxide with selected concentration by stages in the hydraulic fracturing process, wherein the pumping amount in the prepad fluid stage is not less than 70 percent; (4) closing the well for more than 3 hours, and starting to return discharge of a fracturing fluid; and (5) inspecting effects, wherein main indexes comprise critical desorption pressure, daily gas yield and ultimate recovery ratio of the coalbed methane wells or the pumping amount of the underground drill hole. By the method, the daily gas yield and the recovery rate of a single ...

Chemical method for weakening of top coal

The invention discloses a chemical method for weakening of top coal. The method successively comprises the following steps: selecting a coal seam with vitrinite reflectance of R and hard, complete and difficult-to-cave top coal; perforating drilling holes in the coal seam and sealing the holes; preparing an alkali solution, injecting the prepared alkali solution into the drilling holes and carrying out soaking for a period of time; organizing subsequent production according to conventional top coal caving procedures; and comparing the chemical method with traditional physical measures like waterflooding cracking and loosening blasting so as to examine caving improvement effects of the chemical method on the coal seam. According to the invention, the injected alkali solution does not lead to cracks of the coal seam and chemically reacts with the coal seam to rapidly reduce mechanical strength of the coal seam, so caving and drawing characteristics of the coal seam are obviously improved ...

Rapid plugging system for gas explosion of coal mine

A rapid plugging system for gas explosion of a coal mine comprises a shock wave sensor, air bags, air inflation devices, a water spraying device, upper sliding bases, telescopic rods, lower sliding bases, horizontal rods, upper tracks, lower tracks and water spraying pipes. The shock wave sensor is connected with air inflation systems in the air bags and the water spraying device. The two ends of the top of each air bag are connected with the corresponding upper sliding bases, and the lower ends of the air bags are connected with the lower ends of the telescopic rods. The top ends of the telescopic rods are connected with the upper sliding bases, and the telescopic rods can be connected with the lower sliding bases in a butt joint mode. The left upper sliding bases are connected with the right upper sliding bases through the horizontal rods, every two adjacent upper sliding bases are connected through a spring, and every two adjacent lower sliding bases are connected through a spring. The ...

Fuel battery thermoelectric cascade system capable of increasing energy utilization rate of coal bed gas

The invention discloses a fuel battery thermoelectric cascade system capable of increasing the energy utilization rate of coal bed gas. The fuel battery thermoelectric cascade system comprises a fuel treatment device, a fuel battery reaction group, a burning electricity storage device, a heat storage group, an auxiliary temperature control device, a turbine generator, a heat exchange device, a water gas making device, a hot water supply system and a main control system, wherein the fuel treatment device is connected with the fuel battery reaction group; the fuel battery reaction group is connected with the burning electricity storage device, the auxiliary temperature control device and the heat storage group; the heat storage group is connected with the turbine generator; the turbine generator and the burning electricity storage device penetrate through the heat exchange device to connected with the auxiliary temperature control device; the heat exchange device and the water gas making ...

Multi-stage hole collapse prevention construction device for gas extraction holes in soft coal growing area

A multi-stage hole collapse prevention construction device for gas extraction holes in a soft coal growing area comprises a power system, a supporting system, a control system and a positioning system. The power system is connected with the supporting system through a first high-pressure water pipe. The control system and the positioning system are arranged on the supporting system. The multi-stage hole collapse prevention construction device is reasonable in design, easy to operate, safe, reliable, and capable of effectively solving the problem that the gas extraction holes in the soft coal growing area are difficult to form, thereby providing a novel method for gas treatment in the soft coal growing area; moreover, three arc-shaped pipes can be recycled and reused, so that cost is lowered. According to the multi-stage hole collapse prevention construction device, due to the reasonable design of the control system, the axial movement of the three arc-shaped pipes is effectively limited ...

Pore forming, pit building, powder stamping and pressure relief integrated device in soft coal development area

A pore forming, pit building, powder stamping and pressure relief integrated device in a soft coal development area comprises a drill rod (14) of a hollow structure, a conical drill bit (36) is arranged at the front end of the drill rod (14), a steering system, a pit building system and a directional system are arranged in the drill rod (14), the middle of the rear end of the drill rod (14) is connected with a high-pressure water supply system, the steering system and the pit building system are arranged in the drill rod (14) and are connected to the corresponding connecting positions of the drill bit (36) respectively, the rear end of the steering system and the rear end of the pit building system are connected with the high-pressure water supply system, and the directional system is arranged on the lower portion inside the drill rod (14). Due to the reasonable design of the directional system, the direction of a flow jet hole and the direction of a steering hole can be accurately determined ...

Drilling-fixing integrated device and method for yolk coal terrane

The invention discloses a drilling-fixing integrated device for a yolk coal terrane. The drilling-fixing integrated device for the yolk coal terrane comprises a drilling rod, wherein the drilling rod is in transmission connection with an outer power mechanism; the device also comprises an extruding helicoid with a round-table-shaped outline, one end with a bigger diameter of the extruding helicoid is a back end and is fixedly connected to the front end of the drilling rod, one end with a smaller diameter of the extruding helicoid is a front end and is provided with a drill bit and the diameter of the drill bit is the same as the diameter of the front end of the extruding helicoid. The diameter of the front end of the extruding helicoid is small and the diameter of the back end of the sameis big, so that the coal on the periphery of the drilled hole can be extruded in the drilling process, the problem of collapse because the coal layer is very soft is solved, the hole-forming rate of the ...

Plugging equipment for ground fracturing plugging water-bearing stratum

The invention discloses plugging equipment for a ground fracturing plugging water-bearing stratum. The plugging equipment comprises a fracturing plugging feed system, a stirring system and a discharge system, wherein the fracturing plugging feed system comprises two feed pipelines; the first feed pipeline comprises a first fracturing pumper which is connected with a first liquid tank; the second feed pipeline comprises a second fracturing pumper which is connected with a second liquid tank; the stirring system comprises a stirring cabin which is arranged at a well head; stirring blades which are connected with a power device are arranged in the stirring cabin; the discharge system comprises a bushing which is positioned below the stirring cabin and is communicated with the stirring cabin;the wall of the lower part of the bushing is provided with a hole; the lower part of the bushing is positioned in a well; and the first fracturing pumper and the second fracturing pumper are communicated ...

Preparation method of biological fracturing fluid for coal bed methane well

A preparation method of biological fracturing fluid for coal bed methane wells comprises the following steps: (1) screening hydrogenogens and methanogens; (2) acclimatizing related bacteria; (3) enriching the bacteria to prepare A liquid and B liquid, that is, adding the hydrogenogens separated and extracted in laboratory into a culture medium for enrichment for 3-6 days, adjusting the pH to 6.5 to obtain the A liquid, adding the methanogens into another culture medium for enrichment for 20-30 days, adjusting the pH to 7 to obtain the B liquid; (4) adding the A liquid and the B liquid in order according to on-site parameters. The mixed-bacteria fermented biological fracturing fluid prepared in the invention has certain sand-carrying capability; the bacteria in the fluid have hydrogen-producing and methane-producing capability, can not only increase the coal reservoir permeability, increase the coal bed methane resource amount, but also realize automatic viscosity reduction, and facilitate ...

Biological gas production device and method for jointly pretreating coal by aerobic bacteria and anaerobic bacteria

The invention discloses a biological gas production device for aerobic bacteria-anaerobic bacteria combined pretreatment of coal. The biological gas production device comprises a gas blowing system, a flora pre-culture system, an aerobic-anaerobic biological combined pretreatment and gas production system and a gas-liquid two-phase collecting and monitoring system. The invention further discloses a gas production method of the gas production device. According to the method, coal is taken as a substrate, methanogens are cultured and bacterial liquid is optimized under proper conditions, and biological gas production effects under different coal rank, strain type, combined pretreatment mode, treatment time and metabolic environment conditions are simulated indoors. The integrated combined treatment device is adopted, aerobic bacteria and anaerobic bacteria are combined for coal pretreatment, coal biogas can be safely and efficiently carried out, and the integrated combined treatment device ...