Page 203 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

Effect of Gas Wettability on Capillaries CHAPTER 5 187

3. Two core columns with two core slices were taken as experimental
groups (totally two groups). They were put in gas-wetting alteration
agent solutions of 7% and 15% concentration, and saturated by vacuum
pumping. In addition, four core columns and four core slices were
reserved as blank samples for contrast experiment.
4. The core columns and core slices treated with gas-wetting alteration
agent solution were placed in a vacuum drying chamber for drying.
5. The gas permeability of treated core columns was measured. The gas
wettability of corresponding core slices in water or neutral kerosene was
evaluated using the capture bubble method.

5.3.1.2.2 Experimental Scheme
Plan I: Displacement experiment of cores of different gas wettability in “gas/
water” system.
1. Rock sample 0 1 and 7 1 were saturated with distilled water by vac-
uum pumping. Thereafter, the rock sample 0 1 was placed in No. 1
core holder, and 7 1 was placed in No. 2 core holder, immediately.
2. The outlet pressure of the nitrogen cylinder was adjusted to ensure gas
flow at 0.05 mL/min for gas-displacing-water experiment.
3. The time and pressure of water appearing in No. 1 and No. 2 holders
was recorded.
4. The time when water flow of the two holders stopped and the end time
of the experiment were also recorded, corresponding to the volume of
water.
5. When the displacement experiment was completed, the core was taken
down at once for gas permeability measurement.
6. Rock sample 0 1 and 15 1 were saturated through vacuum pumping,
and the experimental procedure 2B5 was repeated.
7. Experimental data was collected and analyzed.

Plan II: Displacement experiment of cores of different gas wettability in gas/oil
system.
1. Rock sample 0 2 and 7 2 were saturated with neutral kerosene
through vacuum pumping. Thereafter, rock sample 0 2 was placed in
No. 1 core holder, and 7 2 was placed in No. 2 core holder,
immediately.
2. The outlet pressure of nitrogen cylinder was adjusted to ensure the gas
flow at 0.05 mL/min for gas-displacing-oil experiment.
3. The time and pressure of water appearing in No. 1 and No. 2 holders
were recorded.
4. The time when water flow of the two holders stopped and the end time
of the experiment were recorded, corresponding to the volume of oil.
5. After the displacement experiment was completed, the core was taken
down at once to measure gas permeability.