A Full-Scale Pore Fractal Modeling Approach for Tight Sandstone Reservoirs Integrating HPMI and LTNA Data

Conventional high-pressure mercury injection (HPMI) alone inadequately characterizes the fractal properties of nanopores in tight sandstone reservoirs, and existing fractal models for HPMI, low-temperature nitrogen adsorption (LTNA), and nuclear magnetic resonance (NMR) lack effective integration. Based on traditional fractal theory, this study develops a unified full-scale pore fractal model that integrates HPMI and LTNA data via a defined conversion coefficient. The model was validated using tight sandstone samples from the Songliao Basin in eastern China and the Turpan–Hami Basin in western China. Results indicate that the proposed model successfully achieves accurate characterization of full-scale pore fractal behavior. Furthermore, it provides a robust fractal-based framework for calibrating NMR T2 relaxation time and constructing enhanced full-scale pore-throat distribution profiles, thereby validating its effectiveness and practical utility as defined in our objectives.