A Drilling Liquid to Reduce the Damage Coalbed Methane

A good protection of coalbed methane reservoir can facilitate its exploitation and use of, cover the shortage of oil and natural gas supply in China, help cut greenhouse gas emissions, phase down environmental pollution and prevent mine accidents from happening. Firstly, damage mechanisms of coalbed methane reservoir in Qinshui basin of Shanxi province were comprehensively analyzed by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), liner swelling test and hot rolling dispersion experiments, thin-section analysis, mercury penetration analysis, wettability measurement and evaluation of sensitivity. Based on this work, pertinent protection counter-measure study were conducted, the surface wettability modifier SLJ-2 and water sensitivity inhibitor SLYZ-1 were selected out, and then drilling fluid for coalbed methane reservoir in Qinshui basin of Shanxi province composed of 0.4%SLJ-2 + 0.5%SLYZ-1 was developed, which has minimal damage to permeability of ingredient under hygrometric state.