The complete paper aims to optimize well trajectories in offshore reservoir development by applying a Pareto-based multiobjective approach. The methodology seeks to minimize key factors influencing well performance and cost, including the number of drilling phases, well length, geomechanical problems, and geohazards. Extending geohazard assessment beyond the main reservoir into the overburden section ensures safer and more-efficient well planning, crucial for maximizing recovery and net present value (NPV).
Introduction
A major source of uncertainty in presalt drilling stems from the interaction between complex geological features and geomechanical instabilities within the overburden. The high capital expenditures and extended planning timelines involved in offshore developments make optimization a critical component of field success.
The industry increasingly has adopted multiobjective optimization techniques, especially evolutionary algorithms. Most existing approaches treat well placement and trajectory design as disconnected problems, failing to integrate subsurface risk assessment, overburden complexity, infrastructure constraints, and trajectory geometry into a unified framework.
This issue is particularly critical in congested or high-risk environments such as Brazil’s presalt fields, where an apparently optimal well placement may become infeasible because of geohazards or proximity to existing subsea infrastructure.
