文301井钾基聚磺饱和盐水钻井液技术

文301井为评价井．位于东渍凹陷文西断层下降盘文301断块．完钻井深为4000m．穿过S1段盐层、S2段上部盐层、S3^2段盐层、S3^3段盐层等多套盐膏层．累计厚度达998m．且盐间物性差别很大．泥膏盐较多，断层多．易盐溶、坍塌、缩径．地层条件相当复杂。针对纯度低、盐层薄的Sl段盐层．采用淡水复合胶液钻井液．针对埋藏深、厚度大的S3^2段、S3^3段破碎泥膏盐混杂结合体．配制钾基聚磺饱和盐水钻井液．从而抑制了盐膏泥层水化膨胀，防止了因层间膨胀性不一致而引起的地层掉块、坍塌．保证了井壁稳定，井径规则．满足了合长盐层段深井优质、安全、快速施工的要求。

Potassium polysulfonate saturated salt-water drilling fluid technology in Well Wen 301

Well Wen 301 is an evaluation well on Wen 301 fault block of Dongpu sag, with a total depth of 4000 m. S1, S2, S32 and S33 saltsbeds were drilled with an accumulative thickness of 998 m, and physical characteristics of all layers are much different. With more shale/gypsum/salt layers and faulted zones, salt dissolution iseasy to occur and sloughing and hole shrinkage often happen. Compound additives drilling fluid was employed to drill S1 salt bed, and potassium polysulfonate saturated salt-water drilling fluid was used to drill S32/S33 salt beds. Results showed hydration and swelling of shale/gypsum/salt intermixture formation were controlled, which prevented the well hole from caving caused by different expansion coefficients among layers, ensuring hole stability and smoothness. It has met the requirement of high-quality, safety, and high drilling speed in thick salt.