Short horizontal sectional radial drilling and fracturing technology of coalbed methane and application

in order to effectively avoid a coal reservoir cllapsed,to reduce the pallition degree to the coal reservoir and to improve the develoment efect of the coalbed methane short horizontal section redial drlling and fracturing fechnology.the shor hoizonal redia mutl branch fillig techmnoiogy was applied to aijuan MiningArea the norh part of cinshuiBasi .The radial rlling and fracturing fechrology could divide the seanm into construction unis and each construction layer all could drill 4 short horizontal radial branches. in a same construcion layer.an azinuth dfferenceof the adjacent radial ranches would be Tm/2 and the adjacent construcion layer would have an azinuth ditference of m( 2n) to the relevant radial tranch.The length ofthe horzontal section radial branch was about 100 m. During the drling process.a clean water igh prssure jet method was appied to thedrlling.Afer the drling completed.an integrated compound fracturing was conducted on the radial branchof each construction layer.Th site application results showed that the technology could make a shor time to have a gas production of the calbed methane,o have a hgh gas production.could effictively conmect the natural racks of the seam.could enlarge the gas drainage reaof the seam.could reduce the polution degree of thecoal reservoi.could avoid the colapse of the coal reservoir and could provide a new efctive production increased path to the coalbed methane development.