Discussion of progressive drainage and separated reservoirs drainage of multiple CBM well in West Guizhou

in order to research the conditons and technolgies during the prces of pogressive drainage of CBM wll on the basises of well-esting and measured parameters of typical CBM well that contained nmutiole superposed CaM system of upper Permian series located in Wwest Guizhou.by means of the seting of variableparameter sequences.,determined parameter sequences and basic paraneter sequences.gas and water producion of each scheme were calculated by COMET3.The critical differences'valuesincluding reservoir prssure,perme billygas content and porosity were 1.14 MRPa、1.31×10-3um1211.33 m3/t,、.042respectivelyby means of defning the ratio between calculated gasproducton of progressive drainage and main layer drainage only in 10 years.Firstlycrainage gas system and secondly drainage system.petween which packer was placed, were fractured in casefrom lower to upper.However.the final drainage system was treated with igh energy gas or othertechnologies of reservoireconstruction rather than fracturing Technology of separated reservoirs drainage.hanging case and communicating tubes were aded to separate gas and water in the wellore,ywas designed to decine the iteriayer interference and inprove gas production in mutple coal seans rea.Numericalsinulatonresults showed that calculative gas production of separated reservoirs drainage increased obviously compared with progressive drainage.