Chemical EOR in Fractured Reservoirs

1. Upon injection of an external fluid into an oil-wet carbonate reservoir, why does the injected fluid (either gas or a surfactant solution) not ‘easily’ imbibe into rock-matrix from fracture?

2. Whatever may be the injected fluid (say, a stable foam with high apparent viscosity in the presence of oil within a single fracture), whether, a simple diversion of fluid remains possible from fracture to matrix? What exactly drives the fluid from fracture into matrix? Is it foam’s stability against high-salinity, high-hardness in-situ brines under elevated temperatures? Should we look for an effective foaming agent or an effective dispersing agent that would remain to be efficient under high-salinity, high-hardness conditions?

3. Whether an enhanced pressure gradient in the fracture remains sufficient enough to improve the fluid flux transfer from fracture into matrix? Or, Is there something more that requires an efficient fluid mass transfer from fracture into matrix? [Note: It’s NOT going to be a simple ‘Take Diversion’]

Suresh Kumar Govindarajan, Professor [HAG]

IIT Madras 14-Dec-2024