Way Down in the Hole - Carbon Capture and Sequestration’s Growing Role in the Energy Industry

The vast potential for permanently storing carbon dioxide underground by using it for enhanced oil recovery can only be realized if produced or captured CO2 can be economically transported long distances via pipeline. And the only way that can happen is if the CO2 is compressed into a “supercritical” or “dense-phase” fluid — a state that is somewhat compressible like a gas but flows and can be pumped like a liquid. When CO2 is in a supercritical state, much more of it can economically flow through a pipeline to the producing field. And when it gets there, the dense-phase CO2 can be injected into an oil production zone, where it has the unique ability to flow through permeable rock formations, bond with and “swell” trapped oil molecules, and free the oil to move to the production well, then up to the surface. Given that CO2-based EOR is destined to become a much more significant activity in the energy industry, it’s time for a fun-filled review of the thermodynamics of fluids as it relates to the transportation of CO2 and its use in the production of crude oil. (Wait! Don’t leave! This will be easy to follow! We promise!) Today, we continue our series on the rapidly evolving CO2 market and why it matters to crude oil producers.

The handful of enhance-oil-recovery producers in the Permian Basin secure virtually all of the carbon dioxide they use from natural CO2 reservoirs located thousands of feet below the surface. In essence, they are taking CO2 out of the ground and putting it back in during the EOR process — producing more crude oil and demonstrating that the CO2 is safely and securely stored underground. Now the challenge is to transform this proven process in a way that reduces greenhouse gas emissions. To do that, EOR producers would need to use man-made or “anthropogenic” CO2 that is captured from industrial and other sources. Well, that’s exactly what’s already happening to a significant degree in EOR operations along the Gulf Coast and in the Rockies, with plans by a leading producer in both regions to use “A-CO2” for the vast majority of its CO2 needs within a few years. In today’s blog, we continue our series on CO2-based EOR with a look at how Denbury Inc. is shifting from naturally sourced CO2 to the man-made stuff.

Carbon-capture projects have been slow to take root in the U.S., but that may be changing as a number of companies are now advancing plans to capture the carbon dioxide that results from ethanol production in the Midwest. Ethanol plants are an obvious choice, given that the CO2 resulting from ethanol fermentation is highly concentrated, which makes capturing it more efficient (and less expensive) compared to many other industrial processes. But while the relative ease and economy of capturing those emissions might seem like a no-brainer, convincing the public to go along with those plans has been more difficult. In today’s RBN blog, we look at what’s being planned.