Page 79 - Reservoir Formation Damage

62 Reservoir Formation Damage

and the surface area and surface area based diameter, d A, are given,
respectively, by:

1/2
(3-30)

Note that y = 1 for spherical particles.
3. Sorting, defined by:

d-d
5 = (3-31)
o
where d g is the average grain diameter, d 0 is the mode diameter,
and a is the standard deviation.
4. Packing, which is the volume fraction of the solid matrix, given by:

(3-32)
where <|) denotes the porosity in fraction.
Triangular diagrams, such as shown in Figure 3-9 by Hohn et al. (1994),
are convenient ways of presenting the relationships between packing,

vvvvvvvvvvvv

75 Cement
25 (incl. coats)

Figure 3-9. A ternary chart showing the relationship between packing density,
intergranular pore space, and cement in Granny Creek wells nos. 1-9, 11,
and 12 (after Hohn et al., ©1994; reprinted by permission of the U.S. Depart-
ment of Energy).