Page 138 - Reservoir Formation Damage

120 Reservoir Formation Damage

CP2-CONTROL CP3 - NIPER BAG -1
LOG - — = 0739

20 30 40 50 70 20 30 40 50 60 70 20 30 40 60 60
Swi, %
WATER SATURATION, 9!
Figure 6-14. Effect of microbial solutions on the capillary pressure curve and
wettability index (after Burchfield and Bryant, 1989; reprinted by permission
of the U.S. Department of Energy).

and temperature. Figure 6-15 by Madden and Strycker (1988) depicts the
shifting of the wettability curves by temperature.

Mineral Quantification
Knowledge of the types, quantities, and conditions of the minerals
forming the petroleum-bearing rocks is important for assessment of their
formation damage potential and design preventive and stimulation tech-
niques to alleviate formation damage. As stated by Chakrabarty and Longo
(1997), "Minerals are usually quantified using mineral properties available
from published data and rock properties measured in the laboratory
used cored samples or in the field using geochemical well logs." In
the literature, several approaches have been proposed for this purpose.
For example, the rapid mineral quantification method developed
by Chakrabarty and Longo (1997) can be used for quantification of
minerals both in the laboratory and downhole. They begin by expressing
each measured rock property, y {, as a mass fraction, f t , weighted sum