Enhanced gas production from low-permeability hydrate reservoirs based on embedded discrete fracture models: Influence of branch parameters

Abstract

The low permeability of marine hydrate reservoirs makes it difficult for trail results to meet the demand for exploitation. Hydraulic fracturing and multi-branch wells are the primary methods for enhancing productivity. This study proposed a new production enhancement method of multi-branch wells combined with multi-stage fracturing (MWMF) based on the embedded discrete fracture model (EDFM). By simulation of the Shenhu area, the multi-physical field evolution of the MWMF production process was first revealed, followed by the systematic analysis of the MWMF production enhancement effect with branch parameters. Results indicated that the cumulative gas production of MWMF increased by 327% compared with only horizontal wells. The production of four-branch wells exhibited a 7% reduction compared to horizontal wells using the MWMF method, suggesting increased branch numbers inhibit production. Increasing branch length was positively correlated with enhanced production. Notably, the influence of branch length on gas production became more pronounced as the number of branches increased. The interface of the three-phase layer (TPL) and hydrate-bearing layer (HBL) was the most suitable location for branch well placement. This novel study provides valuable insights into new applications of the MWMF method in developing low-permeability hydrate reservoirs.