A Study on Quantitative Characterization of Adsorption Capacity of Shale

Adsorption capacity is a fundamental property of shale gas content that is vital to estimation of the shale gas in-place, which is controlled by organic matter (OM) and clay mineral (CM). The adsorption behavior of CM is easily neglected because of the capacity of OM is much more powerful. In this study an improved Langmuir model with adsorbents which including OM, CM and other minerals (Oth) based on adsorption experiments results on four mudstone samples in Northern Songliao Basin was set. The given Langmuir volume (V-L) and Langmuir pressure (P-L) are applied to geological conditions in terms of the empirical formula. Results show that adsorption capacity of CM account for 30% similar to 70% which cannot be ignored in continental lake basin in OM-rich shale (TOC=1%similar to 6%). The verifications for the new model with experimental results in other basins are correct and reliable. Therefore, a new method could be used to predict adsorption capacity of shale reasonably.