5 February 2014

Costain has developed an innovative way of separating carbon dioxide from natural gas which could cut the cost of capturing and storing carbon dioxide and reduce its impact on the environment.

Using in-house process design capability, Costain has filed a patent application at the UK patent office for a process to effectively separate very high levels of carbon dioxide from associated gas. It is the latest in a long line of Costain patents that employ low temperature technology for gas processing and separation.

The developed process technology is particularly suitable for use in Enhanced Oil Recovery (EOR) as it removes carbon dioxide with lower energy consumption and potentially smaller equipment than current competing technologies.

Not only are the processing costs much lower but the process also produces natural gas to conventional transmission specifications as well as natural gas liquids (NGL) for use as fuel and/or petrochemical feedstock.

“If carbon dioxide were stored in existing oil reservoirs rather than in spent oil or gas reservoirs, as is usually considered, then the carbon dioxide can significantly increase oil production from the reservoir to provide considerable revenues” said Adrian Finn, Costain’s Process Technology Manager.

“As the carbon dioxide effectively drives out oil and associated gas from the reservoir it will eventually start to appear in the associated gas and will require removal and recycle to the reservoir. The process technology that has been developed separates the carbon dioxide from the associated gas to provide pure high pressure liquid carbon dioxide suitable for recycle,” said Adrian.

The CO₂ EOR market is well-established in the U.S. oil and gas industry with the first commercial projects dating back to the early 1970s. In the U.S, carbon dioxide used in EOR is mostly naturally occurring. In 2011 over 280,000 barrels of oil per day were produced using this method.

Other nations, and especially those with active oil fields relatively close to carbon dioxide sources, are now considering carbon dioxide based EOR in order to meet carbon dioxide emission targets at a relatively moderate net cost. 

 

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