Hydrological control rule on coalbed methane enrichment and high yield in FZ Block of Qinshui Basin

Abstract

Hydrological control on coalbed methane (CBM) running through CBM pooling, enrichment and high yield, is one of major scientific problems in CBM development. Therefore, hydrological control rule on CBM enrichment and high yield in high-rank coal of FZ Block in Qinshui Basin is discussed and hydrological indices of CBM enrichment and high yield are established by physical simulation, hydrodynamic analysis, hydrochemical analysis and mathematical statistics on the basis of comprehensive analysis of well logging interpretation, analysis test, physical simulation and field exploitation data. The study shows that areas with stagnant groundwater–weak runoff are high in salinity and desulfurization coefficient, and low in sodium and chloride coefficient, conducive to CBM enrichment; within the same enrichment area, the section where change value of groundwater δD/δ18O is less than 0.5 is likely to produce CBM at high rate. On this basis, hydrological indices of CBM enrichment and high yield have been established and 3 possible CBM high yield areas have been selected.