In response to the environmental pollution caused by drilling engineering,to develop an environment-friendly water-based drilling fluid system.Guar gum(GHV-90),pregelatinized starch(GK-K325),and modified castor oil(PCMAS5)were selected as additives.Adopting orthogonal experimental design method,the optimal formulation of the drilling fluid was:1％sodium based bentonite(Na-B)+0.6％GHV-90+1.5％GK-K325+1％PCMAS5.A comparison was made between this environment-friendly drilling fluid and special formation drilling fluids,conducting linear expansion tests,rolling recovery tests,core permeability compression tests,anti-pollution experiments,and biotoxicity tests.Finally,expert opinions were introduced to establish a fuzzy evaluation model.The results show that the comprehensive performance of the environment-friendly water-based drilling fluid is quantitatively rated as good.
维普
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