Geological controls on methane adsorption capacity of Lower Permian transitional black shales in the Southern North China Basin, Central China: Experimental results and geological implications

摘要

The goal of this paper is to investigate the geological controls on the methane adsorption capacity of Lower Permian transitional black shales. To this end, a variety of methods, including quantifying organic matter richness, vitrinite reflectance, kerogen stable isotope analysis, X-ray diffraction (XRD), low-pressure nitrogen adsorption, and high-pressure methane adsorption were performed on black shale samples collected from the Mouye-1 well in the Southern North China Basin. Among them, high-pressure methane adsorption experiments were performed over a pressure range of 0-20 MPa at temperatures of 30 degrees C, 40 degrees C, and 50 degrees C. Then, the effects of organic matter, mineral compositions, pore properties, temperature, and pressure on methane adsorption capacity were analyzed, and a new formula for predicting the gas adsorption capacity and methane adsorption capacity of transitional shales as a function of burial depth in the Southern North China Basin was established.