Page 462 - Petrophysics

430 PETROPHYSICS: RESERVOIR ROCK PROPERTIES

The total flow rate through the block is:

q = 0.533 + 0.0075 = 0.54 bbl/Day

The importance of the fracture to the productivity of reservoirs can
be better appreciated in terms of percentage contribution to the total
flow rate, which for this case is 0.533/0.54 = 98.6%.
The volume of oil contained in the fractures and matrix is [6]
:

Vo = Vom + Vof (7.41)

Where Vom is the volume of oil contained in the matrix, and Vof is
the volume of oil contained in the fractures, which can be estimated
from the following equation:

(7.42)

(7.43)

where: Vo = oil-in-place, m3.
As = surface area of producing formation, m2
h = average thickness of formation, m.
@m = fractional porosity of matrix only.
$f = fractional porosity of fractures only.
Swm = water saturation in matrix.
Sd = water saturation in fractures.

The recoverable volume of oil is:

(7.44)

where: E, = recovery factor for the matrix, fraction.
Ef = recovery factor for the fractures, fraction.

If the permeability of the matrix is negligible, i.e., less than 0.1 mD,
VoR = Vof Ef.
The average permeability of the fracture-matrix flow system can
be obtained from:

(7.45)