In earlier posts I mentioned the use of geoengineering as a way of dealing with excess CO2 emissions. One such method is called carbon sequestration and generally means pumping CO2 emissions into the ground for storage. The Economist has a report on one early attempt:
But few studies have looked at what happens once the gas is in the ground. In October 2004 a group of researchers led by Yousif Kharaka of the United States’ Geological Survey in Menlo Park, California, pumped 1,600 tonnes of carbon dioxide into the Frio formation, a disused brine and oil reservoir east of Houston, Texas. The results of their experiment have just been published in Geology.
The team compressed the gas into its liquid form and pumped it into a layer of sandstone 24 metres thick, lying 1.5km (about a mile) under the surface. They have been monitoring the site ever since, and so far they have found no leaks.
What they have, however, found is that the carbon dioxide has increased the acidity of the water in the aquifer. This, in turn, has dissolved the minerals that hold the sandstone together. As their report puts it, “this rapid dissolution of carbonate and other minerals could ultimately create pathways in the rock seals or well cements for carbon dioxide and brine leakage.”
Of course, the study of this problem is in its infancy; hopefully, as technology improves, other experiments will turn out better.