A pareto-based well placement optimization

In well placement optimization, simultaneously satisfying the investors and environmental agencies is difficult because enforcing environmental regulations have negative impact on economic returns. Thus, a balance between ensuring profitability and keeping to environmental regulations must be found. The NPV is often used as an indicator of economic performance while the VRR is one of the factors used as an indicator of environmental safety. Recently, a study was conducted proposing the use of a weighted combination of the NPV and VRR as an objective function in well placement optimization. This approves the importance of considering both objectives. The approach however, requires that users determine priori the weight of each objective. In this work, we present a Pareto-based multiobjective approach for integrating the NPV and the VRR in a well placement optimization framework. This approach allows us to obtain several optimal instances of well placement, each instance optimal in a particular sense. Differential evolution was used as an optimizer and well spacing constraints were enforced. A set of Pareto-optimal well locations was obtained. A synthetic case is presented to show the usefulness of the approach and analyses of how investors can use these Pareto-optimal well locations in field development planning are presented.