New Scientist reports that: - "The largest carbon burial experiment in the world began in earnest on Thursday when the drilling of a 2100-metre well began in the Otway Basin, on the coast of southern Australia. The project promised the most comprehensive monitoring for leaks to date" "The reservoir is shaped liked an upside-down saucer that is partially-filled with methane gas, and covered by a series of impermeable rock layers". An estimated 100,000 tones of supercritical CO2 will be injected as part of the test, apparently to get more natural gas (methane) out of the ground, and thereafter see how well the earth can hold in the C02. Interestingly, the injected CO2 is not to be sourced from, say, a coal-fired generator. Instead, "They will start by extracting CO2 from a nearby natural geological reservoir and compressing it into a "supercritical fluid" — a gas-liquid hybrid".To their great credit, the project staff is quoted as saying:- ""We need to lay our cards face up, and let the public know what is going on down there. Otway should be a good opportunity to do this." On the scale of the overall climate-changing behavior of our species, sampling for a test like this is rather like asking, "whoof hearted?" on walking into an empty Crapper. So many potential sources of CO2, so little evidence to sort them out. That's why, in part, they have located the test site away from settlements, so influences of other cultural sources of C02 would be minimal (and where a major escape of compressed C02 would pose little hazard).
From just reading the article, we think they deserve an "A" for transparency, but "B" for study design. The public impression would be better, and the feasibily of real world "sequestration" would be more realistically tested, were they to also utilize waste product C02 from fossil fuel combustion sources, keeping track of fugitive emissions along the way.
Tagging the methane-well extracted C02 with a "finger print" blend of carbon isotopes wouldn't be a bad idea either. That way even small leaks could be traced more convincingly, in a sort of Carbon Scene Investigation (CSI) activity.
Tip of the hat to Matt of New Scientist for pointing the story out.
Image credit: New Scientist.