University of Alberta · Calgary, Alberta, Canada
Table 2 lists the measured contact angles of an oil droplet on the surface of oil-saturated end pieces which were immersed into different aqueous fluids. From Table 2, the oil droplet CA ranges between 94° and 108° in fresh water, which indicates that the oil-saturated rock is initially oil-wet in reservoir brine.
For fresh water with different concentrations of nanoActiv® HRT and nanoActiv® EFT, the oil droplet CA is very low, indicating that the oil-saturated rock surface is highly water-wet after exposure to the nanoparticles.
|Relative density (g/cc)||0.74|
|Absolute density (kg/m3)||738.0|
|Surface tension (mN/m)||25.5|
|Total sulphur (mass percent) ASTM D4294||0.107|
Wettability affects relative permeability, electrical properties, nuclear magnetic resonance relaxation times, and saturation profiles in the reservoir. The wetting state impacts waterflooding and aquifer encroachment into a reservoir.
Based on the CA measurement results, it is clear nanoActiv® HRT and nanoActiv® EFT change the wettability of oil-saturated rock surface making it more water-wet. Treatments that change the wettability of the formation from oil-wet to water-wet can significantly enhance productivity.
|Aqueous Fluids||Contact angle of oil droplet on oil-saturated rock surface|
|T=1 min||T=600 min*|
|Fresh water with HRT (5 Wt%)||30°||17°|
|Fresh water with HRT (10 Wt%)||32°||43°|
|Fresh water with EFT (0.5 GPT)||55°||47°|
|Fresh water with EFT (1 GPT)||44°||34°|
*Fresh water contact angle was measured at 60 minutes.
|Aqueous Fluids||Interfacial Tension (mN/m)|
|with HRT (5 Wt%)||0.447|
|with HRT (10 Wt%)||0.373|
|with EFT (0.5 GPT)||0.186|
|with EFT (1 GPT)||0.211|
The interfacial tension between oil and different aqueous fluids were also measured by a spinning drop tensiometer.
nanoActiv® is made in the USA · Patent Pending