Page 463 - Petrophysics

LINEAR FLOW THROUGH FRACTURES AND CHANNELS 43 1

where: kf = fracture permeability
k, = matrix permeability
A = total cross-sectional area
nf = number of fractures per unit area
wf = fracture width,
h = fracture height.

The average permeability of the carbonate reservoir of the above
example can be estimated from Equation 7.45:
where:
wf = 0.0025 = 2.08 x ft, A = 1 ft2, nf = 1, and h = 1 ft.

Inasmuch as:

-- nfwfh - 2.08 x 10-5
A

Therefore:
kmf = (2.08 x 10-’)(340.5) + (1 - 2.08 x 10-5)(10-3)
= 0.072 Darcy

FLOW THROUGH SOLUTION CHANNELS

Craft and Hawkins and Aguilera combined Poiseuille’s law for viscous
flow of liquids through capillary tubes with Darcy’s law for steady-state
linear flow of incompressible fluids to estimate the permeability of
solution channels (Figure 7.5) [ 1, 151. The actual volumetric rate of the

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Figure 7.5. Channel-matrix system.