Contact Angle Evaluation

University of Alberta · Calgary, Alberta, Canada

Nissan Chemical America Corporation is committed to innovative product development. Third-party evaluation provides valuable and unbiased insight into the effectiveness of our solutions and are an integral part of our pursuit of greater product performance and increased customer profitability.

Methodology

University of Alberta scientists polished the end pieces of Montney Formation core plugs to get smooth surfaces for measuring liquid-liquid contact angle (CA) on oil-saturated end pieces by using a high-resolution camera. For CA measurement a contact angle goniometer was used. The oil-saturated end piece is placed into a glass cell which is filled with the fluid sample, then an oil droplet is dropped by a J-shape syringe needle on the rock surface.

Results

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.

Table 1

Summary

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.

Table 2

*Fresh water contact angle was measured at 60 minutes.

Table 3

The interfacial tension between oil and different aqueous fluids were also measured by a spinning drop tensiometer.

Oil recovery factor vs. time for twin core plugs immersed in brine and nanoActiv^® solution. Adding nanoActiv^® in water significantly increases oil recovery rate and the final recovery factor.