Production Parameter Optimization for Complex-Structured Wells Considering Net Present Value

Offshore reservoirs are commonly characterized by complex geology, constrained operations, and high per-well investment. Improving economic performance while maintaining deliverability is therefore a pressing need during field development. By combining multilateral wellbores with staged hydraulic fracturing, complex-structured wells can markedly enhance well–reservoir connectivity; however, for fishbone-type complex-structured wells, published studies still provide limited case-based discussion on how branch-junction loss, completion staging, fracture parameters, and the economic metric jointly affect the final design outcome. In this study, a semi-analytical productivity model for complex-structured fractured wells is developed, accounting for a multi-scale coupling among the reservoir, fractures, and the wellbore. The wellbore and fractures are discretized to quantify the contribution of each completion stage and fracture element to overall productivity. An economic metric with net present value (NPV) as the objective function is then introduced, and a genetic-algorithm-based joint optimization method is established for completion staging parameters and fracture-geometry parameters, enabling an automatic search for the key design variables. The model is validated against water–electric analogy experiments and a field case, demonstrating good predictive accuracy. Case studies show that, with a reasonable parameter configuration, complex-structured fractured wells can significantly increase the cumulative oil production and the NPV under a limited increase in cost; the optimized NPV is improved by approximately 20.2%, illustrating the potential interaction among completion staging, fracture parameters, and the NPV metric under the studied reservoir and economic conditions.