我国某勘探区，地层复杂，在深部地层中膏盐含量较大。在深井钻进时，由于膏盐侵，使泥浆性能显著恶化：粘度、切力增大，失水量上升。如处理不当，往往出现坍塌掉块及井径缩小现象，造成卡钻事故，给顺利完井带来了一定的困难。过去这一地区，在钻井工作中广泛采用丹宁碱液作为减稠剂，采用一部分CMC作为有机失水降低剂。但是在膏盐侵比较严重的 A prospecting area in China has stratigraphic complexity and a large amount of gypsum salt in the deep strata. During deep well drilling, the performance of the mud is significantly deteriorated due to gypsum salt intrusion: viscosity, shear increase and water loss increase. Such as improper handling, often collapse collapsed blocks and bore diameter phenomenon, resulting in stuck pipe accident, to the successful completion of a certain difficulty. In the past, tannin lye was extensively used as a thickener in drilling operations and a part of CMC was used as an organic dehydration reducer. However, salt intrusion is more serious