In the deep water pre salt Santos Basin Petrobras is interested in potential monitoring technologies for detection of carbon dioxide (CO2) in seawater at depths between 1200 and 2600 meters. At these depths, CO2 is not a gas but a buoyant liquid with densities similar to sea water, which makes detection challenging. Also potentially present with CO2 is methane (CH4), which at these depths is close to liquid-hydrate combination, which may possibly cause interference with some measurement techniques used for CO2.

The Federal University of Rio de Janeiro (UFRJ), Ocean Networks Canada (ONC) and Petrobras are developing a test system where carbon dioxide (CO2) and methane (CH4) can be released in controlled amounts to a variety of test instruments at a depth of 2660 meters located over a secure Internet connection with collecting sensor and live video monitoring.

So far, the project has selected several sensors developed by universities, research centers and companies around the world, using different technologies including fiber optic, acoustic and pH. Enabling this in situ real time experimentation is the ONC NEPTUNE cabled observatory. With over 800 kilometers of electro-optic cable to depths of 2660 meters the observatory provides power and Internet connectivity to hundreds of underwater instrumentation making it an ideal laboratory to evaluate technologies in situ. We will describe the design of the experiment at the Cascadia Basin site.

This content is only available via PDF.
You can access this article if you purchase or spend a download.