Fracturing Layer Optimization for Gas Hydrate Development Using EDFM Numerical Simulation Method

With the increasing global energy demand, natural gas hydrates have become a focus of research and development. The South China Sea deepwater area has abundant natural gas hydrate resources, but its low permeability limits the commercialization process. This paper explores how to enhance gas production from natural gas hydrate reservoirs through a combination of fracturing technology and depressurization using numerical simulations. Numerical experiments were conducted under various well types and fracture configurations to evaluate their effects on cumulative gas production. The fracturing layer was optimized for different well types. We employed the embedded discrete fracture model (EDFM) to characterize the fracture structures in the reservoir and coupled it with a conventional hydrate numerical simulator to simulate different fracture morphologies. The results show that fractures in the three-phase layer provide the most significant production enhancement among all tested layers. Fractures within the three-phase layer deliver the largest production gain among all layers tested. By comparing the development effects of different well types, it is found that the combination of horizontal wells and hydraulic fracturing can effectively improve the recovery of hydrates compared with single well types and traditional exploitation methods. In particular, horizontal wells with stimulated reservoir volume (SRV) yield a big rise in gas production compared with the single-fracture model under identical conditions. Fractures in the three-phase layer shows the most significant improvement in production. Horizontal wells under the three-phase layer achieve about an 88.26% increase in production compared with the single-fracture simulation under the same conditions.