Research on Pore Structure and Fractal Characteristics of Tight Sandstone Reservoir Based on High-Pressure Mercury Injection Method

Pore structure is the key element of tight sandstone reservoir, which restricts accumulation and flow oil gas in reservoir. At present, reservoir pore focus difficulty unconventional exploration development research. The Chang 4 + 5 member Upper Triassic Yanchang Formation main for G area. there little research on its fractal characteristics, to some extent affects progress development. This paper selects core samples southern edge Ordos Basin, based high-pressure mercury intrusion experiment, uses theory study characteristics area, thus providing theoretical basis evaluation results show that lithology Basin mainly feldspathic sandstone, with highest feldspar content, followed by quartz, clay mineral chlorite. has poor physical properties strong heterogeneity. There are three area: curve Type I sample two segments, relatively large certain regular, heterogeneity weak; Relatively small pores have no irregular. II shows a three-segment pattern, each size range it gradually gets better increase size. III presents similar one-segment dimension exceeds upper limit 3. It considered full this type does not throat completely irregular or surface rough, very strong.