Royal Dutch Shell Plc  .com Rotating Header Image

Sniffing Oil From The Sky

Jonathan Fahey, 01.21.10, 06:00 PM EST

Shell is working to detect hydrocarbons in the air and track them to oil deposits under the earth’s surface.

Here’s a curious place to look for an oil field buried under thousands of feet of rock: the sky.

But that’s where Royal Dutch Shell ( RDSA news people ) is heading in an attempt to survey huge tracts of rugged and remote terrain that might be hiding oil.

The trick is an instrument Shell is perfecting that can sniff molecular signatures of trapped hydrocarbons floating in the air at concentrations of just 10 parts per trillion. Shell puts the instrument on board an aircraft that flies low (about 1,000 feet) over potential oil territory, sniffing the air and comparing that information with other data collected onboard about the chemistry and structure of the terrain below and the local weather conditions.

Put all that information together, Shell thinks, and it can find interesting places to do more traditional, surface-based early exploration like reflection seismology and drilling test wells. This way is relatively cheap, it can cover lots of ground, and it has the potential to find fields in places it would otherwise be hard to get to.

“You can stuff a plane full of these sensors and fly over the desert to get a picture of the subsurface geology. From there you can look for interesting structures,” says Dirk Smit, Shell’s vice president for exploration technology. “And you can do this over large areas in a short amount of time.”

The big, easy-to-find oil deposits under land have likely all been found, but Shell believes that there are deposits two to three miles underground, hidden under thick layers of salt or basalt that are hard to see through. Looking for oil with traditional seismic technology on dry land is even harder than looking for it under the ocean floor, because the ocean floor is more homogeneous than land.

Still, because of small cracks in the rock and subtle seismic activity, some of the lighter hydrocarbons, like methane and ethane, escape their tombs and percolate to the surface, rising into the atmosphere.

If the underground fields leak too much, Shell is not interested–a leaky field likely means a field that has been emptying for tens of thousands of years. But tiny leaks could be worth looking into.

The trouble is sensing these leaks on board a moving aircraft, bouncing around in the turbulence, and then tracking the molecules, blown about by the wind, back to the place they arose from.

First, a laser system probes columns of air streaming through the airplane to determine the air’s composition and whether there are hydrocarbons. At the same time, instruments on the same plane are recording information about wind speed, altitude and temperature. When put together, the information can show where the hydrocarbons may have come from.

But the plane also carries instruments that can do something called “airborne hyperspectral surveying.” They can look at the chemistry of the ground below while flying over it. Hydrocarbon leaks, even slow ones, will slightly change the chemistry of the rocks below over tens of thousands of years.

The plane carries more traditional equipment as well, things that can measure magnetic and gravitational signatures of the earth that can signal underground formations that could trap oil. All this data together is potentially more valuable than any of it alone, though Shell hasn’t found anything with the technique so far.

Shell has done several test flights over Algerian deserts with a sniffer that can detect methane, trying to perfect its technique. But methane can be produced by human and agricultural activity, so Shell is working to be able to also detect ethane, a heavier hydrocarbon that is not produced by human activity. “Over Holland, you’d just find how many cows there are,” Smit says. “You’d really like to be able to detect ethane, too.”

Because ethane is heavier, less of it percolates, so it’s harder to find. Still, Shell researchers think they can have the ethane detector working by the end of this year, ready to start searching for oil fields in the sky.

To read more of Jonathan Fahey’s stories, click here. Contact the writer at [email protected].

SOURCE ARTICLE and its also non-profit sister websites,,,,, and are all owned by John Donovan. There is also a Wikipedia article.

0 Comments on “Sniffing Oil From The Sky”

Leave a Comment

%d bloggers like this: