In view of the geological characteristics of high pressure in salt-gypsum formation of deep wells in Tarim Piedmont structure, high-density oil-based drilling fluids are widely used, which makes it difficult for subsequent cementing work. In order to solve the technical difficulties of cementing high-density oil-based drilling fluid and salt-gypsum formation in KS well, which is a key exploration well in this area, through analysis of cementing technical problems, combined with salt-gypsum formation cementing and deep well ultra-deep well cementing technology, targeted measures before casing running, optimization of flushing aggravated isolating fluid and aggravating agent are carried out. In addition, relevant technical measures are put forward based on the optimization of cement slurry additives, the design of slurry formulation pipe string structure and the optimization of cementing technology. A set of flushing aggravating isolating fluid was prepared by introducing small particle size, concentrated superfine aggravating agent and hematite powder with relatively large particle size, and a set of high-density cement slurry with good comprehensive performance was obtained by optimizing cement slurry additives and introducing super high-density aggravating agent GM-1. In order to ensure the safety of cementing, the adaptability test of cement slurry formula was carried out, focusing on the adaptability test of cement slurry temperature and density: when the temperature changes + 5 °C the density increases + 0.03 g/cm³, the thickening time of the system changes less than 44 min, the system has good stability, and the anti-channeling performance of cement slurry SPN is less than 3, which has good anti-channeling function and meets the construction requirements, At the same time, the compatibility experiments of different proportions and different media and the simulated intermittent cementing experiments are added to meet the requirements. Field application of KS well shows that the technology can meet the cementing requirement of oil-based drilling fluid in Piedmont area.

针对塔里木山前构造深井盐膏地层高压地质特征，高密度油基钻井液应用广泛，后续固井作业难度较大。为解决本区重点探井KS井高密度油基钻井液和盐膏地层固井技术难点，通过固井技术问题分析，结合盐膏地层固井技术深井超深井固井技术、下套管前有针对性的措施、冲洗加重隔离液和加重剂的优化。此外，在优化水泥浆添加剂的基础上，提出了相关技术措施，浆液配方管柱结构设计及固井工艺优化。通过引入小粒径、浓缩超细加重剂和粒径较大的赤铁矿粉制备一套冲洗加重隔离液，并通过优化水泥浆添加剂和引入超高密度加重剂GM-1。为保证固井安全，开展水泥浆配方适应性试验，重点对水泥浆温度和密度的适应性试验：温度变化+5℃密度增加+0.03g/cm 通过引入小粒径、浓缩超细加重剂和粒径较大的赤铁矿粉制备一套冲洗加重隔离液，并通过优化水泥浆添加剂和引入超高密度加重剂GM-1。为保证固井安全，开展水泥浆配方适应性试验，重点对水泥浆温度和密度的适应性试验：温度变化+5℃密度增加+0.03g/cm 通过引入小粒径、浓缩超细加重剂和粒径较大的赤铁矿粉制备一套冲洗加重隔离液，并通过优化水泥浆添加剂和引入超高密度加重剂GM-1。为保证固井安全，开展水泥浆配方适应性试验，重点对水泥浆温度和密度的适应性试验：温度变化+5℃密度增加+0.03g/cm 通过优化水泥浆添加剂，引入超高密度增强剂GM-1，得到一套综合性能良好的高密度水泥浆。为保证固井安全，开展水泥浆配方适应性试验，重点对水泥浆温度和密度的适应性试验：温度变化+5℃密度增加+0.03g/cm 通过优化水泥浆添加剂，引入超高密度增强剂GM-1，得到一套综合性能良好的高密度水泥浆。为保证固井安全，开展水泥浆配方适应性试验，重点对水泥浆温度和密度的适应性试验：温度变化+5℃密度增加+0.03g/cm³、体系稠化时间变化小于44 min，体系稳定性好，水泥浆SPN抗窜性能小于3，具有良好的抗窜功能，满足施工要求。同时，增加了不同配比、不同介质的相容性试验和模拟间歇固井试验，以满足要求。KS井现场应用表明，该技术能够满足山前地区油基钻井液的固井要求。