Groundwater's Influence On Coalbed Methane Enrichment In Sihe Mining

Based on the geological da ta,structure data and hydrologic da ta of southern Qinshui Bas in and Sihe mining,through analyzing t he hydrat ion dat a of produce d water and groundwa ter flow,t he relationship betwee n hydrogeololgy and coal seam's gas occurrence,salinity`s infl uence on methane solubility,bot h of them were studied.The r esults show that:1?All of the three c oal sea ms that mainly exploited in Sihe mining are influe nced by hydr aulic sealed and hydraulic j am-up,karst collapse columns are mainly in west mini ng,the CBM can be influenced by hydrologic dissolution near the karst collaps e columns.All of the three coal seams are exposed at t he east of e ast mining,wate r can flow in the coal seams to form hydraulic jam-up,there are lack of large structures,it pr ovides a good environment to form hydraulic se aled.From the above,hydr ogeological c onditi on indicates that Sihe mining is conduci ve to make CBM acc umulation.2?The type of produced wat er in Sihe mining is HCO3-Na,salinity degree is betwee n 1100 mg/L and 1500 mg/ L,i t indicates that groundwater runoff is slow and geological conditions is c onducive to make CBM accumulat ion.Wha t`s more,hydration data has shown that the value of SO42-/HCO3-is less than 0.25,it means the produced water belongs to the CBM wells that can produce a large number of CBM,so the hydr ati on data forecasts that the CBM wells in Sihe mining can produce CBM highly and stably.3?Through the analysis of many te sts and their compari son,it shows that with the increas ing of salinity,the solubility of methane rise at fi rst then go down,when the sa lini ty is nearly about 836 mg/L l,the sol ubility of methane get the peak value,when the sal inity is over 2500 mg/L,the va lue of methane dissolved in gr oundwater is les s than pure wat er.