Application of physical simulation in the study of hydrodynamic conditions of Qinshui coal bed methane reservoir

Using the CBM reservoir simulation facilities, the action of hydrodynamic force controlling coal bed methane(CBM) reservoir formation was studied in this paper.The results of experiment showed that under the strong hydrodynamic alternation, δC₁ of coal bed methane reservoir changes from -29.50‰ to -36.60‰, and the lightening process was characterized by phases; CH₄ volume content was reduced from 96.35% to 12.42%; CO₂ content decreased from 0.75% to 0.68%, then rised to 1.13%; N₂ content changed from 2.9% to 86.45%.On one hand, these changes showed the complexity of CBM reservoir formation, on the other hand, they indicated that the strong hydrodynamic action had unfavorable impact on CBM reservoir formation.Meanwhile, the hydrodynamic condition of Qinshui basin with high coal rank was analyzed, and it was found that gas content and hydrodynamic intensity had negative correlation, low hydrodynamic flow condition might result in the high productive and enrichment area of high rank CBM.