| Today,The commonly adopted hydraulic penetration enhancement measures mainly include hydraulic fracturing,hydraulic extrusion,deep-hole high-pressure water injection,hydraulic punching,hydraulic slotting and cutting,etc.These measures often have problems such as complex processes,single adaptation conditions,long operation time,and high labor intensity.It is difficult to meet the higher requirements of coal mine enterprises for gas control work.It is urgent to develop a combination of drilling,punching and fracturing.New type of equipment and technology for gas extraction and production increase,thus integration of hydraulic drilling flushing and fracturing is proposed.This paper uses a combination of theoretical analysis and on-site testing to systematically study the mechanism of integrated drilling and stamping gas extraction and stimulation,the research and development of integrated drilling and stamping tools,integrated drilling and stamping gas extraction and stimulation technology,field engineering tests and evaluation through the high-pressure water jet coal breaking mechanism,hydraulic jet fracturing and fracture enhancement mechanism and hydraulic punching coal pressure relief and permeability enhancement mechanism the following conclusions 1)The integrated technology of drilling and punching is proposed,which can realize the drilling of gas drainage drilling,hydraulic punching of soft coal seam(section),coal pressure relief and permeability enhancement,and hard coal seam(section)hydraulic jet fracturing and fracture enhancement.2)Developed integrated drilling and punching drilling tools,including dual-channel water braid,dual-channel drill pipe,and dualchannel hydraulic ejector,and conducted ground simulation tests at Jiulishan Mine Machinery Plant to further improve the performance of the drilling tool.3)Introduced in detail the use of integrated drilling tools for drilling and punching to achieve cross-layer drilling,drilling along the seam of the coal seam,and gas extraction and stimulation by substituting holes in the underground.The design and construction and other technical processes were discussed in detail,and a multi-channel,multi-stage and universal gas extraction and stimulation technology was formed.4)The field test of the integrated drilling and punching technology was successfully carried out in the 16101 bottom alleyway of Jiulishan Coal Mine.The test results can show that: when using the integrated drilling and punching tool for hydraulic jet fracturing,no mechanical isolation is required.When performing hydraulic punching operations,the parameters such as punching time,coal output and 100-meter gas drainage pure volume are superior to the traditional hydraulic punching technology.Compared with the hydraulic punching technology used in the Jiulishan Mine,the integrated drilling and punching technology shortens the punching time by 60 to 80%,increases the coal output by 2 times,and increases the pure gas extraction volume by 1 to 2 times,which is significant The permeability of the coal seam is increased to achieve the purpose of extraction and production increase.In addition,it can also realize the transformation of gas extraction from the extraction to the rapid and provincial drainage,has higher application value for gas treatment in underground coal mines. |
PDF Full Text Request