Abstract
EOR technologies such as CO2 flooding and chemical floods have been on the forefront of oil and gas R&D for the past 4 decades. While most of them are demonstrating very promising results in both lab scale and field pilots, the thrive for exploring additional EOR technologies while achieving full field application has yet to be achieved. Among the emerging EOR technologies is the surfactant EOR along with the application of electrically enhanced oil recovery (EEOR) which is gaining increased popularity due to a number of reservoir-related advantages such as reduction in fluid viscosity, water-cut and increased reservoir permeability.
Experiments were conducted on 1.5" carbonate reservoir cores extracted from Abu Dhabi producing oil fields, which were saturated with medium crude oil in a specially designed EK core flood setup. Electrokinetics (DC voltage of 2V/cm) was applied on these oil saturated cores along with waterflooding simultaneously until the ultimate recovery was reached. In the second stage, the recovery was further enhanced by injecting non-ionic surfactant (APG) along with sequential application of EK. This was compared with simultaneous application of EK-assisted surfactant flooding. A smart Surfactant-EOR process was done in this study that allowed shifting from sequential to simultaneous Surfactant-EOR alongside EEOR
The experimental results at ambient conditions show that the application of waterflooding on the carbonate cores yields recovery of approximately 46–72% and an additional 8–14% incremental recovery resulted upon application of EK, which could be promising for water swept reservoirs. However, there was an additional 6–11% recovery enhanced by the application of EK-assisted surfactant flooding. In addition, EK was shown to enhance the carbonate reservoir’s permeability by approximately 11–29%. Furthermore, this process can be engineered to be a greener approach as the water requirement can be reduced upto 20% in the presence of electrokinetics which is also economically feasible.
