Key Technologies for Drilling and Completion of Horizontal Shale Oil Wells in the Jiyang Depression

Since the geological conditions of the shale oil reservoir in the Jiyang Depression are complex, there are many technical difficulties during the drilling and completion of horizontal wells, such as high safety risk, low rate of penetration (ROP), low efficiency of wellbore trajectory control, high complex efficiency, and poor cementing quality, etc. The key technologies for the drilling and completion of horizontal shale oil wells in the Jiyang Depression were preliminarily developed, benefiting from the exploration and integrated application of optimization design of drilling engineering, ROP and efficiency enhancement for the horizontal wells, development of high-performance synthetic base drilling fluid, and cementing quality improvement of the horizontal wells. Moreover, these technologies were successfully applied to eight horizontal shale oil wells. The average drilling depth and average ROP were 4402.60 m and 8.86 m/h, respectively, indicating that one-trip drilling was realized in the kilometric horizontal section of horizontal shale oil wells in the Jiyang Depression and thus the complex efficiency was lowered significantly. This study can provide technical support for the effective development of shale oil resources in the Jiyang Depression and a reference for best practices in the exploration and development of other shale oil blocks in China.