Enhanced oil recovery

Captured carbon dioxide gas can be put to good use, even on a commercial basis, for enhanced oil recovery (EOR), and a majority of CCS projects are oriented thus.

This is well demonstrated in West Texas, and today over 5800 km of pipelines connect oilfields to a number of carbon dioxide sources in the USA.

The CO2 acts to reduce the viscosity of the oil, enhancing its flow to recovery wells. It is then separated and re-injected.

At the Great Plains Synfuels Plant, North Dakota, some 13,000 tonnes per day of carbon dioxide gas is captured and 5000 t of this is piped 320 km into Canada for enhanced oil recovery.

This Weyburn oilfield sequesters about 85 cubic metres of carbon dioxide per barrel of oil produced, a total of 19 million tonnes over the project's 20-year life.

The first phase of its operation has been judged a success.

Chevron's Rangely project in the Rocky Mountain area injects 3 million tonnes of CO2 per year supplied by pipeline for EOR in sandstone formations 1800 m deep.

Overall in the USA, over 6200 km of pipelines transport up to 72 million tonnes of CO2 per year that the oil industry uses in enhanced oil recovery, 55 Mt from natural sources, 17 Mt anthropogenic.

This produces 281,000 barrels of domestic oil per day, or 6% of US crude oil production. The EOR industry has captured, transported, and injected large volumes of CO2 for oil recovery over four decades with no major accidents, serious injuries or fatalities.

Present EOR technology has the potential to recover at least an additional 26 billion barrels of US oil, and improved technology could double this, while sequestering over 20 billion tonnes of CO2.

The USA in 2011 set up a National Enhanced Oil Recovery Initiative (NEORI) to help realize CO2-EOR's full potential as a national energy security, economic and environmental strategy.

Its central recommendation is for a production tax credit for CO2 capture and sequestration with EOR.

In Texas, the Port Arthur demonstration project aims to capture 1 Mt/yr of CO2 from two steam methane reformers at Valero Energy Corporation's refinery, selling it for use in enhanced oil recovery.

Another scheme separating CO2and using it for enhanced oil recovery is at In Salah, Algeria.