Effective Porosity: Feasible to measure?
Since, most of a 'petroleum reservoir cross section' remains occupied ‘by rock’ and ‘by oil and water’ that remains securely attached to the rock surfaces by molecular attraction, the ‘actual’ area through which ‘the water and oil keeps flowing’ is definitely going to be lesser than the ‘total’ reservoir cross sectional area of the oil and water bearing petroleum reservoir. In this context, would it remain feasible to deduce this ‘reduced cross-sectional area’ through the fluid (oil and water) keeps flowing?
Is there a way to grab the details on the effects of ‘attached water and oil’ that would probably help us to deduce the extent by which the ‘effective-porosity’ has been reduced from its actual value?
To what extent, this effective porosity would influence the resulting migration of ‘water flow’ and ‘oil flow’?
To what extent, the 'reservoir pressure' would influence the resulting 'effective porosity' associated with a sandstone and a carbonate reservoir?
Is there 'a straight-forward method' to determine the effective-porosity of a petroleum reservoir? If any such direct method exists, then, what exactly (which force) is supposed to drain ‘water and oil’ from those inter-connected pore-spaces?
Feasible to precisely estimate the volume of water and oil that remains retained by the petroleum reservoir as ‘specific retention’ (volume of oil and water that cannot easily drained by free gravity)?
In the absence of precise value on effective porosity, how do we deduce the ‘oil flow rate’ and ‘water flow rate’ exactly?
How do we have a control over the details on
(a) the degree of compaction encountered by matrix-porosity (microscopic porosities); and on
(b) the degree of intensity of fracturing – resulting from overlying rock mass – as a function of depth - towards estimating 'effective porosity'?
To what extent, the extent of ‘effective porosity’ associated with the matrix (primary) and fracture (secondary porosity) in soluble carbonate reservoirs 'gets modified' by 'the process of karstification or dissolution of carbonate minerals' by 'flowing brine containing weak carbonic acid' (assuming major oil fields around the globe remain hosted in limestone and dolomite reservoirs, which keep encountering various depositional environments and processes of its diagenesis)?
When the diameter and throat size, in general, have no relation to sedimentary particle size or sorting in a carbonate reservoir, how do we then deduce the ‘average pore sizes’ in a carbonate reservoir associated with low-permeable rock-matrix; and how exactly, we deduce the 'average fracture aperture thickness' associated with the high-permeable fracture-network?