SCOTTISH RESEARCHERS BEGIN UNDERWATER CO2 LEAK SIMULATION

Tamar Hallerman
GHG Monitor
05/18/12

Researchers began piping thousands of kilograms of CO2 into a bay off the west coast of Scotland this week as part of an experiment to help study the effects of a CO2 pipeline leak on marine life. Researchers inserted a borehole more than 30 feet below the seabed of the Ardmucknish Bay and subsequently drilled a hole to prompt a leak and release small quantities of CO2—roughly 180 to 1,800 pounds per day for 30 days. Project lead Henrik Stahl of the Scottish Marine Institute told GHG Monitor that the team will observe the area for 90 days to examine how the CO2 disperses through the water and affects marine life. Researchers will also study the method by which nearby sediment recovers from the leak. “In a localized spot and in a very controlled way, we’ll be able to see how the CO2 affects the geochemistry of the sediment and potentially how the CO2 affects the fauna and the microbes,” Stahl said earlier this week. “Although we’re examining a limited area, this will be more than enough for us to see what we want to see.”

Stahl said that researchers will be monitoring the CO2 through the sediment by sending sound pulses to the sea floor, which can help distinguish the gas from sediment. He said his team will also use seismic testing to judge how quickly the gas rises through the sediment and sensors to monitor the spread of CO2 as it disperses into the water, which he said will help inform computer models of CO2 dispersion. Sediment cores will also be taken for chemical and microbial analysis, he said. In particular, Stahl said that researchers are interested in the pH level of the water as CO2 levels increase. Earlier tests have indicated that CO2’s presence will likely lower the pH, increase the acidity of the surrounding water and could potentially a large impact on the marine ecosystems.

Most European CO2 Storage Projects Offshore

The simulated leakage project is part of a larger four-year research effort to better understand how the U.K.’s marine environments react to potential leaks from underwater carbon storage operations, as well as to develop technology to help monitor marine environments for leakage. The effort is a particularly relevant one for Europe, where most of the continent’s CO2 storage projects are slated for offshore development. Norway’s Statoil currently runs two of world’s oldest CO2 storage projects, both offshore at Sliepner and Snøhvit. More recently, the Netherlands barred all onshore CO2 storage, while the U.K. said it will only accept entries into its CCS demonstration program that plan to inject CO2 into offshore saline aquifers or depleted oil and gas reservoirs. “The main driver for us is that CCS is quite big now in the U.K. and Scotland,” Stahl said. “In order to [deploy CCS on a large scale], decision-makers and stakeholders need to have this kind of information in order to proceed with this process.”