Trajectory Calculation for Complementing 3-D Well Path Planning in Geosteering Operations

Abstract Geosteering has an essential role in the wellbore’s placement in the pay zone, which significantly affects a well’s production life. Different geological boundaries and mechanical constraints guide the geosteering decision-making to plan a well trajectory inside the reservoir. Even though most geosteering studies are based on 2D models, the well trajectory is built in a 3D environment. Therefore, the present paper focuses on the geometrical design of the geosteering operations inside a boundary volume to reach a new wellbore position respecting a set true vertical depth (TVD), inclination, azimuth, and 3D curvature with the shortest path distance. Such distance is determined by stochastic simulations where a systematic disturbance in the rotary steerable system (RSS) and random and systematic errors from the environment are introduced. The results show that the proposed geosteering method can effectively determine the optimal path distance to achieve a wellbore position with the required confidence factor and acceptable tortuosity, regardless of whether planar or non-planar curves are used in the optimized planned path. The geosteering method relies on a 3D model designed to complement the well path generation in the existing geosteering models, assisting the application of steering commands for directional drillers (DDs) or drilling automation systems.