FRACTAL DIMENSION AND ITS INFLUENCING FACTORS OF CONTINENTAL SHALE OIL RESERVOIR BASED ON NITROGEN ADSORPTION EXPERIMENTS.

In this paper, taking the Chang 7 Member of Yanchang Formation in Block H of the Ordos Basin as an example, the fractal characteristics of continental shale were systematically studied based on nitrogen adsorption experiments. The research results show that brittle minerals can significantly improve the pore structures and gas-bearing properties of shale. Nitrogen adsorption experiments show that in a relatively low pressure environment (P0<0.5), the adsorption-desorption curve is in a reversible form. When the relative pressure is large (P0>0.5), a larger hysteresis loop appears. The fractal dimension D1 has a good positive correlation with clay minerals, quartz, calcite and dolomite. The more the specific pore volume of the micropore increases, the greater the increase in the value of fractal dimension D2. In addition, both clay minerals and quartz have a good positive correlation with the fractal dimension D2. The main reason is that the pore types of the shale are mainly interlayer pores of clay minerals and intergranular pores of clay and quartz particles. The correlation between calcite and fractal dimension D2 is poor, and dolomite has a certain negative correlation with fractal dimension D2, which is related to the inhibition of pore development by dolomite. [ABSTRACT FROM AUTHOR]