ROP Improvement Technology for Horizontal Shale Oil Wells in Daqing Oilfield

Technical difficulties including borehole wall instability, large friction torque, and long drilling cycles are encountered while drilling horizontal shale oil wells in the Gulong Block of Daqing Oilfield. For the purpose of efficient and rapid development of shale oil, a series of research works have been carried out. In light of the formation characteristics and drilling construction difficulties of the block, a third-spud casing program was optimized to ensure safe well construction in the target shale formation. According to drilling practices and existing techniques, the wellbore trajectory was upgraded to reduce the construction difficulty. In addition, the research was performed considering the hole shrinkage in the second-spud vertical section and the long drilling cycles in the third-spud build-up and horizontal sections. The research was performed on the tools and technologies, such as borehole wall dressing tools, rotary screws, sand cleaning joints, and hydraulic oscillators, and the drilling parameters were optimized. Finally, a rate of penetration (ROP) improvement technology for horizontal shale oil wells in Daqing Oilfield was developed. Field tests were conducted in three horizontal wells in Daqing Oilfield, with an average well depth of 4 691 m, an average drilling cycle of 35.23 d, and an average ROP of 19.03 m/h (enhanced by 53.7%). The research and tests demonstrate that this technology can provide technical support for the efficient development of shale oil in Daqing Oilfield.