COMPARATIONS BETWEEN MERCURY INTRUSION AND GAS ADSORPTION FOR PORE STRUCTURE CHARACTERISTICS OF SHALE

According to the differences of pore structure characteristics between marine and continental shale in China, the Weiyuan and Jiao Shiba marine shale and Yaoqu continental shale are selected to test. The main test methods contain thin section analysis, mineral and main quantity analysis, low field scanning microscopy, mercury injection and gas adsorption. Based on the research results of pore structure characteristics and controlling factors, the new standards of pore size naming are put forward. The pores are divided into < 2nm, 2~100nm, 0.1~1μm, 1~10μm, 10~100μm, >100μm. They are respectively called ultramicropore, micropore, small hole, middle hole, big hole, and capillary hole. The sample porosity development degree from high to low in turn are 2^#, 5^#, 1^#, 6^#, 4^# in 2~100nm pore range. The samples porosity development degree from high to low in turn are 2^#, 1^#, 4^#, 6^#, 5^# in 10~100μm pore range. Pore distribution uniformity coefficient h_u is proposed. Micro-nano pore of sample 2 and sample 5 are more development comparing to other samples. Also gas storage capacity of sample 2 and sample 5 are stronger. The test results of N₂ adsorption, CO₂ adsorption by using DFT model and mercury intrusion can be unified to attain continuous distribution of nanometer pore.