Practice of Trajectory Control Technology for Directional Wells with Small Deviation in Yan’an

Abstract The well track irregularity, azimuth drift, and slow ROP are severe problems in the build and maintain angle sections of wells on An 7 platform. By analyzing the influences of structure factors of steerable assembly with one bend on the guiding ability, the stabilizer counts, positions and outer diameters in assembly is optimized. The BHA scheme which is suitable for small inclined directional well is proposed. Results show that some measures can be implemented, such as 1) predicting “azimuth advance angle” in directional drilling and 2) drilling 4-6m by sliding then drilling 3-5m by composite method during angle building process. These findings can improve the pertinence and operability of BHA, and enhance the ratio of composite drilling footage.