Trajectory optimization for horizontal shale gas well by integrating wellbore stability

摘要

In this paper, the optimization model has been established to optimize 3D horizontal well trajectory in shale gas field. Two types of well trajectory have been discussed according to the whole trajectory and the correction trajectory. The sensitivity analysis of wellbore stability versus inclination angle and azimuth angle is conducted. The optimization model takes drilling depth as objective function and takes wellbore stability, dogleg severity as constraints. A new heuristic algorithm named differential search algorithm (DS) has been applied to optimize well trajectory combined with penalty function. At last, case study is presented and it demonstrates that the proposed optimization model can obtain a trajectory with minimum drilling depth under the constraints of wellbore stability and dogleg severity. It also indicates that DS has an excellent performance with high accuracy and stability for 3D well trajectory optimization.