煤层气井钻井液特点的探讨

Probe into Features of Drilling Fluid in Coalbed Gas Well

煤层气参数井一般要求采用清水钻取煤心,生产井则主要采用无粘土钻井液、优质钻井液或清水施工。应用清水或无粘土钻井液钻井时,孔内产生的岩屑或岩粉进入煤储层后,会堵塞煤层裂隙或孔隙,降低煤层气产能。而应用优质钻井液钻进时,由于泥皮的过滤作用,能更好地保护煤层不受伤害,同时能降低钻井施工风险,确保井内安全。

Parameter well of coalbed gas ask for generally coal coring with fresh water, but the productive well ask for construction mainly with clayless high quality drilling fluid or fresh water. During drilling progress used fresh water or clayless drilling fluid, the drilling cutting of drill hole enter into coal reservoir, can block up fracture and pore of coalbed, decrease yield of coalbed gas. But if use high quality drilling fluid, because of filtration of mud cake, can to protect coalbed more better, and in the meantime, decrease risk of drilling construction, ensure safety in well.