Trajectory control techniques for 3-D arc wellbores with z-incline

The purpose of drilling Well Wang 4-Xie 5-3B is to produce inter-well remaining oil.Due to the ground conditions,the well has to be designed as z-shaped well trajectory,so as to increase the bare area of oil layers and fulfill the geological requirement.It gets more difficult to control the 3-D arc well trajectory with z-incline,since there is no reference data both in China and abroad.It is possible to adjust the well deviation and orientation into the scope of design successively,based on the mechanism of Shanijin graphic and the strict control of setting angles.What’s more,setting angles compensation methods have to be applied to adjust tool surface on time,so as to adjust azimuth as much as possible by drilling the shortest footage.The well features in low total angular change rate,smooth well trajectory,and good drilling results,laying a solid foundation for the research and application of directional wells with narrow curves and variable azimuth.