Systems and methods for the in situ extraction of materials, for example lunar regolith, from a celestial body. The systems and methods described herein can be used in outer space or on Earth. A high pressure gas is delivered to loosen up the material and form a borehole. A deployable mast deploys from a stowed, coiled configuration to a linear, deployed configuration into the borehole. A deployable tube may deploy to assist with delivering the gas and/or collecting the loosened material. One or more jets emit the gas. The jets may be supported at a free end of the tube or mast. The jets may direct loosened material through the tube and/or mast toward a collection reservoir. A flow separator may filter the loosened material from the gasses.

A method for constructing an artificial water-conducting channel through pulse hydraulic fracturing of drainage boreholes in a roof aquifer includes constructing an artificial water-conducting channel in a sandstone fissure aquifer through arrangement of drainage boreholes and pulse hydraulic fracturing, which improves the permeability of dense and intact sandstone rock masses. The artificial water-conducting channel formed through arrangement of drainage boreholes is connected to discontinuous water-bearing areas and water-rich areas, and water from roof sandstone fissures is diverted to the drainage boreholes through the artificial water-conducting channel, thereby achieving effective drainage of the boreholes and expanding a radiation range of single-borehole drainage. The method not only avoids the arrangement of excessive drainage boreholes and significantly improves the drainage efficiency of prospecting and drainage boreholes, but also facilitates advance drainage during the mining process. The method enables effective control of mine water hazards, thereby ensuring safe production of the mine.

A method for constructing an artificial water-conducting channel through pulse hydraulic fracturing of drainage boreholes in a roof aquifer includes constructing an artificial water-conducting channel in a sandstone fissure aquifer through arrangement of drainage boreholes and pulse hydraulic fracturing, which improves the permeability of dense and intact sandstone rock masses. The artificial water-conducting channel formed through arrangement of drainage boreholes is connected to discontinuous water-bearing areas and water-rich areas, and water from roof sandstone fissures is diverted to the drainage boreholes through the artificial water-conducting channel, thereby achieving effective drainage of the boreholes and expanding a radiation range of single-borehole drainage. The method not only avoids the arrangement of excessive drainage boreholes and significantly improves the drainage efficiency of prospecting and drainage boreholes, but also facilitates advance drainage during the mining process. The method enables effective control of mine water hazards, thereby ensuring safe production of the mine.

Methods of hydraulic fracturing a rock mass as part of a method of establishing a block cave mine or extending an existing block cave mine includes (a) drilling a plurality of holes downwardly into the rock mass using drill rig equipment positioned on the ground above a proposed or existing block cave mine; and (b) injecting a hydraulic fracturing fluid into the drilled holes from above-ground hydraulic fracturing equipment and inducing fractures in the rock mass. A hydraulic fracturing equipment installation located above-ground drills a plurality of holes downwardly into the rock mass and injects a hydraulic fracturing fluid into the drilled holes and induces fractures in the rock mass. A non-metallic casing for drilled holes is also disclosed.

Methods of hydraulic fracturing a rock mass as part of a method of establishing a block cave mine or extending an existing block cave mine includes (a) drilling a plurality of holes downwardly into the rock mass using drill rig equipment positioned on the ground above a proposed or existing block cave mine; and (b) injecting a hydraulic fracturing fluid into the drilled holes from above-ground hydraulic fracturing equipment and inducing fractures in the rock mass. A hydraulic fracturing equipment installation located above-ground drills a plurality of holes downwardly into the rock mass and injects a hydraulic fracturing fluid into the drilled holes and induces fractures in the rock mass. A non-metallic casing for drilled holes is also disclosed.

The present invention relates to a technical solution of unloading pressure and shocking preventing, achieved by 3D stratified buffer and energy absorbing belt in thick coal seam. It is a technology for Prevention and Control of the Impact of Ground Pressure in Coal Mines that with Thick Coal Seam Bottom Roadway. Firstly, determine the distribution length L of the supporting stress curve along the advancing direction of the working face, divide the independent impact prevention unit by L, and sequentially determine the length L1 of the stress elevation zone, the length L2 of the stress critical load zone, the length L3 of the stress decline zone, and the length L4 of the stress static load zone, and also determine the different parameters of the spacing of the cutter drilling holes within the different stress zones; In the vertical direction of the working face, determine the height of the coal body stress stabilization zone H1, the height of the stress increase zone H2 and the height of the stress superposition zone H3 in turn, and determine the parameters of the cut slits and the location of the blocking grooves in different zones within the different stress zones. The appropriate jet parameters are adopted in different stress areas, and barrier slots are formed by continuous cutting at the junction of different partitions, which can both perform the function of coal unloading and block the stress transfer, solving the problems of insufficient and uneven unloading of coal seams.

The invention discloses an enhanced extraction system based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam, including an ultrasonic excitation and acid fracturing integrated drilling device, an ultrasonic control box and a mixing tank. The invention further discloses an enhanced extraction method based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam. The invention has the advantages of realizing intercoupling of ultrasonic excitation and acid fracturing, improving the pore structure of coal, enhancing the connectivity between pores and fractures, promoting gas desorption and improving gas extraction efficiency of coal seams.

The invention discloses an enhanced extraction system based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam, including an ultrasonic excitation and acid fracturing integrated drilling device, an ultrasonic control box and a mixing tank. The invention further discloses an enhanced extraction method based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam. The invention has the advantages of realizing intercoupling of ultrasonic excitation and acid fracturing, improving the pore structure of coal, enhancing the connectivity between pores and fractures, promoting gas desorption and improving gas extraction efficiency of coal seams.