Carbon Dioxide Enhanced Oil Recovery

In Carbon Dioxide Enhanced Oil Recovery, you'll learn ...

• The benefits and limitations of carbon dioxide (CO₂) enhanced oil recovery (EOR)
• Why injecting CO₂ into the pore spaces of a rock helps move crude oil out
• The physical elements of a typical CO₂ flood operation
• Real-world examples of how a field can respond to CO₂ injection

Overview

Credit: 2 PDH

Length: 22 pages

When an oil reservoir is first produced, the pressure that exists in the subsurface provides the energy for moving the oil, gas and water that is in the rock to the surface. After a while, the pressure dissipates and pumps must be used to remove additional volumes of oil. Depending on the characteristics of the rock and the oil, a considerable amount of the original oil in place may be left behind (perhaps 60 percent or more) as residual oil.

As the production decline phase begins, it is carefully managed to extract every last drop of oil possible using enhanced oil recovery techniques, such as waterflooding and CO₂injection. Where CO₂enhanced recovery operations are employed, they typically take place after the less expensive waterflooding option has already been implemented, although the remaining oil saturation in the post-waterflood reservoir is still significant, perhaps 50 percent of the original oil in place.

In a typical CO₂flood operation, a pipeline delivers the CO₂to the field at a pressure and density high enough for the project requirements and a meter is used to measure the volume of gas purchased. This CO₂is directed to injection wells strategically placed within the pattern of wells to optimize the areal sweep of the reservoir. The injected CO₂enters the reservoir and moves through the pore spaces of the rock, encountering residual droplets of crude oil, becoming miscible with the oil, and forming a concentrated oil bank that is swept towards the producing wells.

This course provides a brief introduction to the physics of CO₂ EOR, the fundamental engineering aspects of its application, and the conditions under which it can be successfully implemented.