Reservoir Engineering: Relative Permeability

1. If relative permeability could vary considerably throughout the reservoir, depending on the local pore structure, and interactions between the fluids and rock, how could we measure relative permeability @ lab-scale?

2. With reference to the measurement of two-phase relative permeability, at the laboratory-scale, would we prefer steady-state measurement of relative permeability as it minimizes the capillary end effects, albeit being a time-consuming method?

(where, all of the fluid phases with a fixed ratio are injected simultaneously into the reservoir rock @ constant flow rate, until, the system reaches equilibrium, i.e., until, the saturation and the pressure drop become steady)

Or

Unsteady-state method of relative permeability, albeit it’s one-dimensional assumption, along with the requirement of a high flow rate?

(a relatively faster method; and here, usually only one fluid is injected into the sample to displace the in-situ fluid; and further, saturation is not required to achieve equilibrium)

3. To what extent, could we rely on two-phase relative permeability data in order to generate three-phase relative permeability (brine-oil-gas system) by means of empirical correlation?

Can these empirical models accommodate the various flow conditions, complex pore structures and non-uniform wettability trends associated with a real field reservoir?

Further, if, depending on the local pore-geometry and the local variations in fluid properties, if different locations of a petroleum reservoir yield different displacement regimes based on the coupled and dominant effect(s) of viscous, capillary, gravity and inertial forces, how could a single experimental measurement will be able to represent all the flow regimes that occur in a petroleum reservoir?

On the other hand, are we considering the effect of viscous forces in pore network modelling?

Are we able to provide a proper input to the pore network modelling with reference to the topological and geometrical details of the real field pore networks – extracted from rock-microstructure images? Capturing complex pore-scale details won’t lead to heavy computational cost?

Suresh Kumar Govindarajan

Professor (HAG)

https://home.iitm.ac.in/gskumar/

https://iitm.irins.org/profile/61643

20-Aug-2024