Locating “Ice That Burns”

By Jade Boyd

According to the Department of Energy, commercial development of just 1 percent of the United States’hydrate resources would more than double the nation’s proved gas reserves.

Composed of ice crystals that melt into a gas that can ignite, methane hydrates have been dubbed “ice that burns.”

They’re formed tens to hundreds of meters below the ocean floor, where temperatures plunge and the weight of the water above exerts pressures of thousands of pounds per square inch. As much as 20 trillion tons of methane are estimated to be locked away in gas hydrates on the outer edges of the Earth’s continents, and according to the Department of Energy, commercial development of just 1 percent of the United States’ hydrate resources would more than double the nation’s proved gas reserves.

The problem is finding it.

But that may have gotten a little easier thanks to the award-winning research of Rice graduate student Gaurav Bhatnagar, who works in the lab of George Hirasaki, the A.J. Hartsook Professor in Chemical and Biomolecular Engineering.

Bhatnagar has developed a way to use a single variable — the depth of the interface between sulfate and methane in marine sediments — as a shorthand measure to effectively predict where hydrates will occur and the quantity of the hydrate accumulation.

“Sulfate can be measured more accurately than other geochemical data and may be a better indicator of the presence of gas hydrates,” Bhatnagar said. “Moreover, sulfate data can be obtained from shallow cores, which also avoids the complications arising from drilling through hydrate layers.”

The importance of Bhatnagar’s work hasn’t gone unnoticed. In 2006, he won the Society of Petroleum Engineers’ Gulf Coast Regional Student Paper Contest, the SPE’s International Student Paper Contest and an Outstanding Student Paper Award from the American Geophysical Union. The research is supported by Rice’s Shell Center for Sustainability and by a Kobayashi Graduate Fellowship.

For more information about Rice’s gas hydrate research, visit www.ruf.rice.edu/~hydrates.