Trajectory control technology for Well Xuwen X3

Well Xuwen X3 is a multi-target directional well, deployed in Maichen depressed block in Beibuwan Basin. The section of the second spud has large wellbore diameter and long open-hole section with the length of 2 667 m. The open-hole length of the third spud is 1 540 m. The geothermal gradient is high, and the electrically measured temperature is 211℃ in the depth of 5 974 m. The high geothermal gradient in the area affects the performance of MWD instrument, so multi–point measurement is necessary for lower formations, leading to wellbore trajectory control posterity. To achieve effect Well Xuwen X3 wellbore trajectory control, tapered hole assembly is used for the vertical interval, with length of 2 028 m，and the biggest hole angle is only 1.39 degree. For directional interval, the screw drill with 1.5 degree is used to orientate. In angle holding interval, the packed hole assembly and slightly building assembly are used. The four target points meet the drilling design and hole trajectory conforms to the demand of design, with the drilling depth of 6010m and the horizontal displacement of 2 017.22 m. It provides experience for similar well drilling operation.