COMPARATIONS BETWEEN MERCURY INTRUSION AND GAS ADSORPTION FOR PORE STRUCTURE CHARACTERISTICS OF SHALE
LI Zhiqing1,2,3, SHEN Xin2,3, QI Zhiyu2,3, HU Ruilin2
1. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology), Chengdu 610059;
2. Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029;
3. University of Chinese Academy of Sciences, Beijing 100049
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 hu 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.