A Multi-Block Material Balance Framework for Connectivity Evaluation and Optimization of Water-Drive Gas Reservoirs

Carbonate gas reservoirs are often characterized by strong heterogeneity, complex inter-well connectivity, extensive edge or bottom water, and unbalanced production, challenges that are also common in many heterogeneous gas reservoirs with intricate storage and flow behavior. To address these issues within a unified, data-driven framework, this study develops a multi-block material balance model that accounts for inter-block flow and aquifer influx, and is applicable to a wide range of reservoir types. The model incorporates inter-well and well-group conductive connectivity together with pseudo–steady-state aquifer support. The governing equations are solved using a Newton–Raphson scheme, while particle swarm optimization is employed to estimate formation pressures, inter-well connectivity, and effective aquifer volumes. An unbalanced exploitation factor, UEF, is introduced to quantify production imbalance and to guide development optimization. Validation using a synthetic reservoir model demonstrates that the approach accurately reproduces pressure evolution, crossflow behavior, and water influx. Application to a representative case (the Longwangmiao) field further confirms its robustness under highly heterogeneous conditions, achieving a 12.9% reduction in UEF through optimized production allocation.