▎ 摘　　要

NOVELTY - Water-based drilling fluid system comprises 3-8 g bentonite, 0.1-0.8 g sodium hydroxide, 0.5-2.5 g fluid loss agent, 2-6 g nano plugging agent, 1-6 g well wall enhancer, 0.1-0.6 g inhibitor, 0.1-0.6 g coating agent, 2-6 g fine calcium, 15-30 g composite salt, barite and water (balance amount). USE - Used as water-based drilling fluid system. ADVANTAGE - The water-based drilling fluid system can well stabilize the well wall in the process of drilling well and reduce the underground complex condition. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparing water-based drilling fluid system comprising dissolving the bentonite in water, soil slurry, the soil slurry, sodium hydroxide, fluid loss agent, nano plugging agent, well wall enhancer, inhibitor, coating agent, fine calcium, composite salt, mixing uniformly to form base liquid, according to the density of the water-based drilling fluid system, adding barite into the base solution, mixing uniformly to obtain the water-based drilling fluid system.