Fluid Flow through Petroleum Reservoirs: Role of Reservoir Engineers in the last couple of centuries (1827 - present)
From Navier-Stokes Equation in 1846 (derived by Navier, Poisson, Saint-Venant & Stokes between 1827 and 1845), it nearly took a decade to deduce an explicit momentum conservation equation that addresses single-phase incompressible fluid flow through a saturated homogeneous and isotropic porous medium under steady-state conditions namely Darcy’s law in 1856.
The extension of Darcy’s law for transient, compressible, multi-phase fluid flow with gravity and capillary effects remained “nearly” feasible using Muskat’s formulation in 1937 - despite - using the concept of ‘pressure gradient’ as against ‘hydraulic gradient’; and using the concept of ‘permeability’ as against ‘hydraulic conductivity’, although it did not remain as an analytical solution of the NSE but rather, it reflected the macroscopic resultant of solutions in which, the Darcy-flux (volumetric fluid flux per unit macroscopic area of the porous medium) and the fluid pressure are to be considered as statistical averages over a REV.
Even with the introduction of ‘fluid potential theory’ by Hubbert in 1953, we still cannot simply add all the numerical values of different potential energy to estimate the fluid potential because the scales and magnitudes of potential energy defined by different forces remain too different (for example, quite often, the interfacial potential energy arising from the capillary pressure remains orders of magnitude lower than that of the fluid potential that reflects only the macro migration of hydrocarbons); and in essence, the absolute values of the fluid potential are no more comparable.
And, the exploration of mathematical models is still going on at its own pace.
If so, will it remain so easy to give up the very idea of ‘fossil fuels’, which has not even begun its journey in full swing? On the other hand, on a lighter note, whether all the trees are not storing solar energy (naturally) in the form of ‘carbon’ – which, after ‘some’ great geological times become fossil fuels??