An efficient and fast shale oil cluster well drilling technology for Shengli Oilfield

Shale oil reservoirs in the Jiyang Depression of Shengli Oilfield are developed in continental faulted basin, and correspond to multiple sets of high-quality source rocks, implying a great potential for development. However, these reservoirs are challenged by complex geological conditions for drilling, wellbore instability and difficult bit selection. Through researches on overall optimization of well group design, optimization and control of wellbore trajectory, structural optimization and selection of drilling tools, associated ROP enhancement technology, and precise managed pressure drilling (MPD), an efficient and fast shale oil cluster well drilling technology was developed. So far, 12 of the test wells have been drilled. For Well Niuye-XX, in the 53 d drilling period, the average rate of penetration (ROP) was 22.3 m/h in the second spud-in, 47.3% higher than that in the early stage; the ROP reached 13.04 m/h in the third spud-in by using the assembly of NOV bit + rotary steering + steering motor + hydraulic oscillator; in the middle-late stage of drilling in horizontal section, the assembly of high temperature-resistant downhole motor + double hydraulic oscillator enabled a high reservoir penetration. Coupling with actual drilling data, suggestions and focuses on future development of the efficient and fast shale oil cluster well drilling technology are proposed.