Page 173 - Gas Wettability of Reservoir Rock Surfaces with Porous Media
P. 173
Effect of Gas Wettability on the Surface Properties CHAPTER 4 157
FIGURE 4.22
Examples for changes in gas contact angle in water with time. (A) Changes in gas contact angle θ gas-
water in water with time (9 wt% gas-wetting alteration agent); (B) Changes in gas contact angle θ gas-water
with time in water (3 wt% gas-wetting alteration agent).
smaller the gas-wetting initial contact angle of the surface of treated cores, and the
more unstable the bubble; i.e., the faster it disappears on rock surfaces. The reason
bubbles disappear is because bubbles adhere to the solid/liquid interface and tear
it, forming a three-phase solid/liquid/gas boundary. At this time, bubbles and the
saturated air inside the dry cores form a continuous phase leading to the bubbles
disappearing. The stronger the bubble wettability, the larger the area of bubbles
spreading on solid/liquid interface, and the faster the bubbles disappear.
4.4.2 Unidirection Imbibition Process of Cores
4.4.2.1 UNIDIRECTION SELF-ADSORPTION OF CORES EXPERIMENTAL
PROCEDURE
As displayed in Fig. 4.23, two pieces of dry core columns (saturated air) were
taken out from a group of samples, and treated by gas-wetting alteration agent
