Shale gas content is composed of free gas contentand adsorbed gas content.The free gas content may be inf-luenced by porosity

gas saturation

density

pressure and temperature

whilethe adsorbed gas content is affected by organic carbon content

organic matter maturity

pressure and temperature.The adsorption capacities of organic matters of diffe-rent types(adsorption/TOC)of shale are quite different

and show the sequence of Ⅲ>Ⅱ>Ⅰ.Thus

different formulas were proposed for the calculation of free gas content and adsorbed gas content.Through analyzing and selecting the key factors for shale gas content

and based on relational theoretical calculations

charts of shale gas content were developed for different organic matter types

so as to quickly and accurately calculate shale gas content.Overall

shale gas content increases with depth

but the increment decreases progressively.The theoretical values calculated with the charts correlate well with the field measured values

indicating the wide applicability of these charts.The theoretical shale gas content obtained with these charts can provide a reliable basis for the reasonable evaluation of shale gas resource potential and prediction of play fairways in the early stage of shale gas exploration when the available geologic parameters are rare.