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Sample Data
The following data was collected by running four separate tests on the
following oilfield base fluids:
Fresh Water
Fresh Water + Glycol
Fresh Water + Potassium Acetate
Fresh Water + G Surfactant
Each individual test was run for 18 hours.
The wafers were prepared from materials of 100% Na-Montmorillonite
(Bentonite), gumbo shale, and mixtures of bentonite/shales/sands. Also used
was clay of medium to low reactivity similar to the material commonly referred
to as “Rev Dust.” The wafers were compressed at 6,000 PSI for 30 minutes.
The results and interpretation of the graphs using micro and macro temporal
criteria clearly explain the following phenomena:
1. Reactivity of the fluid and resulting consequences on the wellbore stability
2. The differential speed it takes the additives to reach the surface of the
mineral material
3. The probable distribution of the additives on the surface of the mineral
material related to its molecular shape and molecular weight
4. Steric impediment phenomenon (space behavior)
5.
Synergetic phenomenon
6.
Depletion of the additive concentration over time
7. The mineral composition and physical characteristics (porosity,
permeability) of the mineral matrix vs. the percent of expansion.
