高温高密度油基钻井液在四川盆地页岩气井中的应用

Application of Oil Based Drilling Fluid with High Temperature and High Density in Shale Gas Wells in Sichuan Basin

由于四川盆地页岩气区块地层压力系数高、井底温度高,存在钻井液性能不稳定、井壁失稳等难题.通过研发出新一代润湿反转剂、降滤失剂,调整水相中氯化钙的质量分数,改进了高温高密度油基钻井液体系性能,解决了高温高密度油基钻井液在四川盆地页岩气井钻探中出现的黏度升高、破乳电压下降等稳定性能方面的问题.该研究对前期在涪陵地区页岩气井钻探中应用的油基钻井液体系进行了补充和完善,提高了高温高密度油基钻井液的抗高温周期,保证了钻井液性能稳定.

In allusion to the problems of high formation pressure coefficient,high bottom hole temperature,instability of drilling fluid,wellbore instability in the shale gas block of Sichuan Basin,a new generation of wetting reversal agent and fluid loss additive was developed,the mass fraction of calcium chloride in water phase was adjusted and the performance of oil based drilling fluid with high temperature and high density was improved,by which the problem of instability of viscosity increase and reduction of emulsion breaking voltage in the oil based drilling fluid of shale gas wells in Sichuan Basin is solved.The oil based drilling fluid used in shale gas well drilling in Fuling Area is supplemented and improved,the high temperature resistance cycle of the oil based drilling fluid is improved and the stability of drilling fluid performance is guaranteed.