Macro scopic modeling of gas production from shale reservoirs

Abstract

The demand of unconventional resources like shale gas and tight oil has increased in recent years due to two crucial empowering different horizontal drilling technologies and multistage induced fracturing. The productivity of gas from shale reservoirs depends upon the reservoir parameters and the hydraulic fracture properties. For producing shale gas from the complex matrix and fracture network, an efficient model has to be developed. In addition, the distribution of pore sizes in shale gas reservoirs and conventional gas reservoirs are relatively different. As the major portion of gas is in adsorbed state, the diffusivity equation of conventional gas reservoirs is not suitable to define the gas flow in shale reservoirs. So, a new diffusivity relation, which includes the different transport mechanisms like gas slippage, gas diffusion and gas desorption, has to be developed to model a gas flow in shale reservoirs. Moreover, there is high cost and huge uncertainty in the development of shale gas reservoirs because of several uncertain reservoir and fracture parameters. Therefore, an efficient approach to perform sensitivity analysis in respect of Langmuir volume, Langmuir pressure, matrix porosity and matrix permeability for the development of shale gas reservoirs is desirable.