Fault Block Shale Oil Horizontal Well Drilling Speed Enhancing Technology in Subei Basin

The shale oil geological resources in Subei Basin are 1.569 billion tons, which is an important way to realize sustainable development in the old field. To solve the problems of optimizing the wellbore structure design, poor wellbore stability, difficulty in controlling the wellbore trajectory, and high risk of well control in horizontal oil shale drilling.Based on geological engineering integration, the technology of layered speed-up drilling for shale oil horizontal wells was developed, which includes optimizing the wellbore structure and trajectory, personalizing the PDC drill bit design, and selecting the optimal drilling tools combination. The technology also integrates enhanced parameter drilling, friction reduction and torque reduction to improve drilling speed, strong sealing white oil-based drilling fluid and double-density drilling fluid fine pressure control and anti-pressure surge safety drilling technologies. This technology has been applied to 5 shale oil horizontal wells, with the drilling cycle reduced from 90.74 days at the beginning to 28.20 days on average, and the average mechanical drilling speed increased from 7.19 m/h to 16.47 m/h. The research results show that this technology meets the drilling speed-up requirements for shale oil horizontal wells in the Su Bei fault block and provides engineering technical support for the subsequent economic scale development of shale oil.