Enhanced Oil Recovery (EOR) increases the ultimate recovery of oil from a reservoir beyond primary or natural recovery.
Underground Energy's team has significant experience in evaluating and implementing EOR techniques and believes there is potential for enhanced oil recovery methods across most of its asset base. Of the many EOR techniques historically used in the Santa Maria Basin and California oil fields, UGE particularly favors the application of those that conserve energy, increase operational efficiency and give maximum consideration to the environment.
EOR techniques typically involve the injection of fluids to re-pressurize the reservoir, sweep oil toward production wells, and/or change the physical parameters of the oil or rock to improve the recovery of oil over time. Water or natural gas is injected in secondary EOR to replace fluids withdrawn from the reservoir in order to maintain or increase the reservoir pressure and to drive oil to producing wells. In certain types of reservoirs, carbon dioxide or surfactants (detergents) may be injected for tertiary EOR to improve the sweep of oil by reducing the surface and interfacial tension of oil and water and increasing the relative permeability of the reservoir to oil. When the in situ oil viscosity is high, oil recovery can be increased by injecting steam into the reservoir to heat the oil and thereby lower its viscosity to improve flow. Certain organic polymers may be injected improving the mobility ratio of the injecting fluid to “drive” viscous oil from the reservoir. In medium and light oil, microbes have been used to clean globules of oil trapped in the reservoir.
While EOR techniques increase the cost of oil production, if properly designed, they can also substantially increase oil production and ultimate recovery. When designed properly, EOR techniques will result in robust economics, especially during periods of favorable oil pricing. Fluid injection is done so under strict compliance with federal and state clean water regulations and multiple precautions are taken to ensure the fluids do not impact any fresh water aquifers that may overlie the oil reservoir.