Differential effect of hydrothermal fluid in formation and accumulation effect of coalbed methane in West Guizhou

in order to disuss the coupling geological mechanism of hydrothermal fuid in coalbed methane system,this paper compared the geolgical character ofthe hyrothermal fuid between Zhjin and Panwian in West Guizhou.and analyzed the geological po.ess ofenrichment and accumulaton of coalbed methane from newperspeciveof hydrothermal fud civties in formation.The resuls showe that two stages regional thermal fuid activties happened in the Zhijin and Panxian.In the early stage,the cacium fuid was the carier but it became t iliceou fuid and a small mount of cacun fuid in the laler stage.The fomer was the resut of themal cycling effect of fui in formation and the laterwas caused by the diferental njection of dep- source and high temperature fuid. The hydrothermal fuid inpelld coalbed nethane to generate and migrate at igh intensty aiong with producing dense swarms tubular pores,which were coincident withtfactonic stre.s.Aks a resut.the cal ody was broken and the porosity and permeablity of cal vere affcted obiously. one of the most important factors which lead to high stess in coalbed nethane system was the relatively closed and stranded hydrothermal fuid enironment in coal measure strata.Plafom upise in the nrtheast of Gizhou region was just in such anenvironment:where the high temperature fuid could provide more favorable conditions for the enrichment and accumulation of coalbed methane.