Study on improved efficiency of induced fracture in gas hydrate reservoir depressurization development

The existence of solid hydrate in porous media always greatly reduces the relative permeability, which limits the development of hydrate reservoirs. Therefore, to recover the gas, it is necessary to carry out reservoir reconstruction measures that induce fractures around the production wells to increase the gas production of hydrate reservoirs. At present, there is limited quantitative research on the promotion of gas production by induced fractures in hydrate reservoirs. In this paper, numerical models of Class III hydrate reservoirs with induced fractures are established. By comparing the gas production with and without induced fractures, the effectiveness of induced fractures in promoting the depressurization production of natural gas hydrates is verified. An index of improved efficiency is established and calculated to measure the promotion effect of induced fractures during the fracture promotion stage. The multiple regression calculation formulas of improved efficiency with reservoir geological parameters are obtained by integrating nonlinear regression and linear regression. The calculation model is helpful to quickly and directly measure the rationality and economy of the induced fracture depressurization method to promote hydrate development.

Automated summary

The existence of solid hydrate in porous media greatly reduces the relative permeability, which hinders the development of hydrate reservoirs. Reservoir reconstruction measures, such as inducing fractures around production wells, are necessary to increase gas production. This study establishes numerical models to verify the effectiveness of induced fractures in promoting depressurization production of natural gas hydrates. The calculation model obtained in this study can measure the rationality and economy of the induced fracture depressurization method for promoting hydrate development.