盐下复杂地层井身结构优化及突破盐丘钻井技术

哈萨克斯坦肯基亚克盐下油藏属于地质奈件复杂、高压低渗碳酸盐岩油藏。开发难度大，巨厚盐丘给钻井带来许多潜在的风险，如缩径、卡钻、挤毁套管等。在分析盐下油藏地层压力剖面基础上将表层套管与首层技术套管合二为一，制定了详细的固井工艺措施，优选出了两性离子聚磺饱和盐水钻井液体系并制定了维护处理措施，使得在厚达3000m以上盐层钻进时钻井液性能稳定、井径规则、井眼畅通，解决了由盐层溶解、垮塌以及盐层塑性流动所引起的阻卡、划眼等井壁稳定问题。井身结构的简化，使钻井周期明显缩短．节约了大量钢材和水泥，产生了巨大的经济效益和社会效益。

Casing Program Optimization and Drilling Technology for Sub-Salt Carbonate Reservoir

The sub-salt carbonate reservoir in Kenhkiak, Kazakhstan, features abnormal pressure and low permeability, and complicated geological conditions, which contributes difficulties to development. In addition, the huge thick salt dome allows a series of potential drilling risks, for example, undergauge, stuck pipe, casing collapse, etc. Through analysis of formation pressure profile, the paper considers it is completely possible to merge the surface casing and the first technical casing. By designing detailed anti salt cementing technology and optimizing drilling fluids, it realized that penetrating the thick dome up to 3 000 m smoothly with stable wellbore built and non pipe-stuck. The simplification of casing program allows the shortening of drilling duration, saving of steel and cement cost, huge economic and social benefit.