Effect of Fracture Conductivity Attenuation on Two-phase Non-Steady Deliverability

Abstract

In the actual development of deep low-abundance extra-low-permeability reservoirs, fracture conductivity damage may be harmful to reservoir performance, arising from proppant crush under the effective closure pressure. Inadequate attention has been given to research on how fracture conductivity attenuation is related to proppant behaviour and how conductivity loss affects seepage field and well deliverability. A prediction model of fracture conductivity considering proppant crush is innovatively established. On this basis, a method, called two-way asynchronously coupling analytical solution and numerical simulation at selected time-steps, is formed to investigate how pressure difference affects fracture two-phase non-steady deliverability. Finally, the effect of fracture conductivity attenuation on two-phase unsteady liquid-producing capacity and the recovery of reservoir is analysed. It is found that the larger the pressure difference, the higher the well deliverability, but the more serious the fracture conductivity attenuation, resulting in greater decrease of the well deliverability. Therefore, formulating development technical policy requires choosing the appropriate pressure difference between production and injection.