Gas-bearing characteristics of coal measure strata and logging evaluation of fluid pressure systems.

This article focuses on developing evaluation models and a comprehensive logging division method to characterize fluid pressure systems and gas-bearing layers within coal measure strata in the southeastern margin of the Ordos Basin. Using experimental tests on rock and gas samples alongside gas logging, array acoustic wave logging, and conventional logging data, the study classifies coal measure lithology into five types and quantitatively assesses formation sealing ability through porosity and breakthrough pressure models, identifying mudstone and limestone as key separation layers. The coal measure gas (CMG) in the area is predominantly thermogenic, with gas-bearing layer prediction methods ranked by sensitivity as array acoustic logging, gas logging, and conventional logging. Ultimately, the strata are divided into three fluid pressure systems distinguished by reservoir thickness and pressure gradients, providing insights to guide the co-exploration and co-production of CMG.