Adsorption features of fracturing fluid by coal substrate during the fracturing process in coalbed methane well

During the fracturing process in coalbed methane wells,since the coal bed is featured by cleat development and large specific surface area of coal,the adsorption injury arising from coal features cannot be ignored.The paper conducts a series of researches and probes into the adsorption of fracturing fluid by coal substrate.Therefore,the study classifies,for the purpose of simplification,the complicating system into three types of adsorption components,namely,the organic component represented by GC/MS analysis results,the adsorption component represented by inorganic substance analysis,and the organic component of guar gum and its scission chain after viscosity breaking.As indicated by the analysis results of anthracite and long flame coal,the coal samples have stronger adsorption performance to organic elements,which is also demonstrated by the IR analysis results before and after the adsorption.