Water Saturation and Distribution Variation in Coal Reservoirs: Intrusion and Drainage Experiments Using One- and Two-Dimensional NMR Techniques

Determining water occurrence in pore-fracture systems under specific saturation is of great significance to reveal the correlation between content and porosity/permeability coal reservoirs. In this work, simulation experiments intrusion drainage are used study micro-occurrence migration using NMR T2 T1–T2 techniques discuss influence system structure parameters on micro-occurrence. Meanwhile, distribution heterogeneity clarified by single- multifractal theories. The results show that (1) vacuum method without pressure unsuitable for high-rank samples with micropore development, variation leads a change significant permeability when greater than critical value, which related rank degree fracture development; (2) single-fractal theory can characterize pore size static conditions; however, analyses have stronger applicability characterizing dynamic (3) good sample characteristics such as volume pores fractures. process centrifugation, both D–10–D0 D–10–D10 from fractal decrease linearly samples, indicating decreases an increase centrifugal force; (4) two-dimensional spectra same should be comprehensively analyzed they quantitatively identify amount at different stages.