Key Engineering Technologies for Three-Dimensional Development of Multiple Formations of Shale Oil in Jiyang Depression

The complex engineering geological conditions of shale oil in Jiyang Depression lead to some pro-minent problems, such as a long drilling cycle, high complex time efficiency, and difficulties in controlling cementing quality and fracturing. In response to them, key engineering technologies for the three-dimensional development of multiple formations of shale oil reservoir were developed through technology research and integration, including drilling engineering design for three-dimensional development in multiple formations, technologies for improving drilling speed and efficiency, technologies of preventing drilling fluids from pollution by shale oil, cementing technologies for horizontal sections, and fracturing technologies for high-efficiency stimulation. These key technologies were applied in the FY pilot demonstration well group. The average drilling cycle of eight wells in the group was 59.58 d, and the average completion period was 69.95 d. The complex time efficiency was decreased by 51% compared with that before the application of these technologies, and 252 sections were fractured successfully. The results of research and field application demonstrated that the series of technologies can tackle the technical problems in the three-dimensional development of multiple formations shale oil in Jiyang Depression and improve the relevant technical level, providing engineering and technical support for the effective development of shale oil resources in Jiyang Depression.