Page 89 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

Evaluation Methods and Influencing Factors CHAPTER 2 73

32
Free energy of n-hexadecanehas/air interface
28 Free energy of glass slide surface
24
γ (mJ/m 2 ) 20
16
12
8
4
0
–0.8 –0.7 –0.6 –0.5 –0.4
Gas wettability index of air on the surface of glass slide with respect to
n-hexadecanehas ζ
gas–hexadecanehas
FIGURE 2.34
Relationshipbetween gas-wetting parameter ζ gas-liquid and interface free energy.

ζ gas-hexadecanehas in the air, gas wettability index of gas on the
surface of glass slide with respect n-hexadecanehas
–0.4

–0.5
ζ gas-hexadecanehas –0.6

–0.7

–0.8
0.4 0.5 0.6 0.7 0.8
A Hex Work of adhesion

FIGURE 2.35
Relationship between ζ gas-hexadecanehas and work of adhesion A Hex .

replace air. Therefore with respect to n-hexadecane, air is in the nonwetting phase
on the glass slide surface.

2.4.2.2.2 Study of the Effects of Surface (Interface) Free Energy
on Gas Wettability Using Bubble Capture Method
1. Experimental Materials
In the experiment, air and n-octane are taken as the medium for con-
tact angle measurement in water, and the glass slide treated with