Fluid distribution and pore structure multifractal characteristics analysis of coal measure mudstone

It is of great significance to delineate the features fluid migration and pore structure heterogeneity coal measure mudstone reveal its influencing factors for improving shale gas production recover. Based on response Low-field nuclear magnetic resonance under fully brine water saturated, centrifugal at 12000 rpm heating-treatment 80 °C, T2 capillary bound clay ranged from 0.57 0.987 ms 0.596–0.909 ms, respectively. Correspondingly, movable fluid, saturations were between 25.76% 83.73%, 1.24%–15.31% 13.42%–69.33%, And calculated lower limits effective pores in 1.84–185.84 nm. The structures mudstones presented strong heterogeneity. total organic carbon (TOC) was negatively correlated with Hurst Index (H) Δα, while connectivity increased maturity increase over mature stage. effects minerals opposite feldspar. Clay mineral H resulting positive fluid. Additionally, quartz content, did reverse. In addition, carbonate pyrite heterogeneity, increases content tends be improve mudstone. Furthermore, porosity, permeability, reservoir quality index flow zone indicator have been found obviously reduce Meanwhile, tend weaken connectivity. However, such may certain enhancement