Abstract: A hole protection system and a method for coal seam slotting and fracturing combined drainage. The system includes a hydraulic slotting subsystem, a hydraulic fracturing subsystem and a flexible hole protection system. The hydraulic slotting subsystem includes an ultra-high pressure water jet generating module, a drill pipe drilling tool module, an orifice sealer, a gas slag separator and a drilling rig. The hydraulic fracturing system includes an emulsion pump station, a water tank, a hole sealing device, a fracturing string and a casing. The flexible hole protection system includes a front end fixing device, a water injection support pipe, a first flexible support and a water injection connecting section.

Abstract: Disclosed are a hole protection system and a method for coal seam slotting and fracturing combined drainage. The system includes a hydraulic slotting subsystem, a hydraulic fracturing subsystem and a flexible hole protection system. The hydraulic slotting subsystem includes an ultra-high pressure water jet generating module, a drill pipe drilling tool module, an orifice sealer, a gas slag separator and a drilling rig. The hydraulic fracturing system includes an emulsion pump station, a water tank, a hole sealing device, a fracturing string and a casing. The flexible hole protection system includes a front end fixing device, a water injection support pipe, a first flexible support and a water injection connecting section.

Abstract: Disclosed is a method for identifying secondary reservoir formation boundaries and combined extraction of multiple asymmetric mining coalbed methane. This method fully combines the displacement transfer mechanism after multiple mining to determine its influence on a horizontal thrust of overlying strata after a first mining, and then determines evolution characteristics of pressure arches. Combining the identification of different types of pressure arches with a layout of a surface well accurately determines a secondary reservoir formation range of coalbed methane. By adopting the method of mining face overlying strata in series for combined extraction, coalbed methane from multiple mine faces is extracted by one well to greatly improve the coalbed methane extraction effect.