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川西致密碎屑岩双重介质气藏具有纵向储集层多、多压力系统,砂体中含多种粘土矿物成份,水敏和硷敏严重;作为导流通道的裂缝压力敏感性强,给保护气层的钻井完井液的评价选择带来难度.针对这一特点,研究采用了钻井液滤饼质量特性评价方法,并结合钻井液体系的伤害评价,室内筛选保护气层的钻井完井液体系.通过对CACL2 ?KHM 、三磺和两性复合离子聚合物三种低PH 值、低滤失量的钻井液体系试验评选,确定了适合川西致密碎屑岩双重介质储层的钻井液???两性复合离子体系及其配方.评价试验中,为了消除多次围压的加载、卸载对裂缝岩心渗透率的影响,设计改进了仪器系统,以提高模拟评价结果的可靠程度.“,”The tight clasolite dual porosity media gas reservoirs in West Sichuan are of multiple reservoirs longitudinally,multiple pressure systems,various clay mineral compositions in sand body,serious water sensitivity and alkali sensitivity and high pressure sensibility of the fractures acting as flow passage,bringing difficulties to the evaluation and selection of the drilling and completion fluids for protecting gas reservoirs.In view of this character,the evaluation method for drilling fluid filter cake quality character was adopted and the drilling and completion fluid systems for protecting gas reservoir were selected in room by combining with the damage evaluation of the drilling fluid system.Through the test and evaluation of the three drilling fluid systems with low pH value and low filter loss,i.e.CaCl 2 KHm,three sulphonates and amphoteric composite ion polymer drilling fluid systems,the drilling fluid-amphoteric composite ion system and its formulation suited to the tight clasolite dual media reservoirs in West Sichuan were determined.In order to eliminate the effect of the loading and offloading by multiple confining pressures on the fractured core permeability,the instrument system was designed and improved in the test to raise the reliability of the analog evaluation results.