Evaluating the Potential of Multi-Stage Fractured Horizontal Wells in Developing Low-Permeability Hydrates Using Numerical Production Models and DCF Approach

Multi-stage fractured horizontal wells are a critical technique for enhancing the productivity of low-permeability hydrates in the Shenhu Area of the South China Sea, yet their economic feasibility remains unclear. In this study, an improved discounted cash flow model was developed, incorporating economies of scale in drilling and fracturing costs, as well as production efficiency. A systematic multi-factor evaluation was conducted based on field-scale numerical simulation data. The results indicate that all un-fractured scenarios yield negative net present values (NPVs) ranging from −30 to −43 million RMB, confirming their economic infeasibility. Among the fractured scenarios, the optimal combination was identified as a fracture stage spacing of 10 m and a production pressure of 1 MPa, achieving an NPV of 65 million RMB, an internal rate of return of 51.9%, and a payback period of approximately 2 years. Sensitivity analysis reveals that gas price is the most influential factor (sensitivity range: 216 million RMB), followed by horizontal well section length (123 million RMB) and gas–liquid separation efficiency (109 million RMB). In contrast, cost-related parameters—including drilling, fracturing, production system, and operation and maintenance—exhibit low sensitivity, each below approximately 12 million RMB. The recommended technical portfolio for the Shenhu Area comprises a fracture stage spacing of 10 m, a production pressure of 1 MPa, a horizontal well length of 900–1200 m, and a downhole gas–liquid separation efficiency of ≥85%. Viewed from an economic standpoint, these findings provide technically optimized engineering solutions for fractured horizontal well projects in hydrate development.