Page 155 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

Effect of Gas Wettability on the Surface Properties CHAPTER 4 139

Table 4.11 Calculation Result of Molecular Adsorption of Nitrogen
Rock Adsorption Model Adsorption Adsorption
Wettability Distance Distance De
Re r/nm kJ/mol
Liquid-wetting Liquid-wetting (Three 0.264 2 10.058
rocks condensed ring models)
Liquid-wetting Liquid-wetting (Six 0.254 2 10.877
rocks condensed ring models)
Gas-wetting Gas-wetting (Three carbon 0.388 2 4.009
rocks atom models)
Gas-wetting Gas-wetting (Six cdarbon 0.399 2 4.689
rocks atom models)

FIGURE 4.11
Diagram of most stable state of models with different wettability adsorbing N 2 molecules.

well depth illustrates that the nitrogen adsorption of liquid-wetting rock sur-
faces and gas-wetting rock surfaces are all physical processes (surface con-
densed-agglomeration) (Table 4.12).

4.1.3.4.6 Adsorption Capacity of Different Molecules of Liquid-
wetting Model Surfaces
On liquid-wetting rock surfaces, the sequence of adsorption capacity from
strong to weak is: water＞carbon dioxide＞nitrogen＞methane. Water forms strong