Optimal Design of Deviation-Correction Trajectory Considering Inter-Well Interference

Abstract

In the process of shale gas mining, if the actual well deviates from the planned trajectory, significant inter-well interference will occur. Therefore, in order to reduce production loss, operators want to get back on the planned trajectory economically. To obtain the best deviation-correction trajectory, an optimization model considering inter-well interference was established. Firstly, the function relation between production envelope and deviation distance is constructed to calculate the production loss. Then, based on the deviation-correction trajectory design, the deviation distance under different curvature trajectory is obtained. Finally, the production loss of different trajectory is obtained, and a new multi-objective optimization model for deviation-correction trajectory is established. Based on the field data of Fuling shale gas area in China, the established model is verified. The results show that the smaller the curvature value is, the greater the production loss occurs. When the curvature value exceeds 10.8°/30m, the production loss value remains minimal. With the same production loss, the longer the production time leads to the greater well profile energy. When the optimization objectives are considered comprehensively, a trajectory with lower well profile energy and higher production can be obtained. It is concluded that the established model can not only reduce the probability of drilling accidents but also achieve better shale gas production. This study fully considers various factors affecting horizontal well in shale gas area, which can provide theoretical guidance for the design of deviation-correction trajectory.