Page 72 - Reservoir Formation Damage

Petrography and Texture of Petroleum-Bearing Formations 55

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Figure 3-3. Thin-section images of various pore types (after Davies, ©1990
SPE; reprinted by permission of the Society of Petroleum Engineers).

Frequently, for convenience, pore space is perceived to consist of pore
bodies connecting to other pore bodies by means of the pore necks or
throats as depicted in Figure 3-4. Many models facilitate a network of
pore bodies connected with pore throats as shown in Figure 3-5. How-
ever, in reality, it is an informidable task to distinguish between the pore
throats and pore bodies in irregular porous structure (Lymberopoulos and
Payatakes, 1992).
Interconnectivity of pores is a parameter determining the porosity of
the porous media effective in its fluid flow capability. In this respect, the
pores of porous media, as sketched in Figure 3-6, are classified in
three groups:

1. Connecting pores which have flow capability or permeability (conductor),
2. Dead-end pores which have storage capability (capacitor), and
2 Non-connecting pores which are isolated and therefore do not
contribute to permeability (nonconductor).

The interconnectivity is measured by the coordination number, defined
as the number of pore throats emanating from a pore body. Typically, this