针对江苏油田地层的特性，通过钻井液体系的抑制性、配伍性评价，优选了两性离子聚合物保护油气层钻井液，并探讨了保护油气层机理即中和粘土表面的负电荷，防止储层的碱敏性，防止微粒运移，减少亚微米颗粒进入储层，屏蔽暂堵。现场应用表明，该体系表现出类似ＭＭＨ 钻井液特殊的流变性和类似于两性离子聚合物的强抑制性和低的滤失量。提高了钻井速度，缩短了完井周期，减少了钻井液对储层的浸泡时间，满足了钻井工程的需要，保护了油气层。 In view of the characteristics of formation in Jiangsu Oilfield, we optimized the drilling fluid of oil and gas reservoirs by zwitterionic polymer through inhibition and compatibility evaluation of drilling fluid system, and discussed the mechanism of protecting oil and gas reservoirs by neutralizing the negative charge of clay surface and preventing reservoir Alkali resistance to prevent the migration of particles, reduce submicron particles into the reservoir, shielding temporary plug. Field applications show that this system exhibits a specific rheology similar to MMH drilling fluids and strong inhibition and low fluid loss similar to zwitterionic polymers. Improve the drilling speed, shorten the completion cycle, reduce the drilling fluid to the reservoir soaking time, to meet the needs of drilling engineering, to protect the oil and gas layers.