Undersea robot aims for 3-D image of BP oil plume

(Reuters) – Scientists geared up on Wednesday for a 12-day trip in the Gulf of Mexico with an undersea robot they hope will capture 3-D images of oil plumes from the BP spill.

Green Business | Barack Obama | Gulf Oil Spill

Oceanographers and others have been monitoring the plumes of oil, gas and dispersant chemicals coming from the broken BP wellhead since soon after the April 20 explosion on the Deepwater Horizon drilling platform.

An underwater video camera shows the oil gushing from the wellhead on the sea floor, and aerial and ship observations have charted where the spill has drifted on the water’s surface.

But the exact location and the extent of oil and other chemicals in the water column have been harder to determine.

The scientists’ robotic vehicle would try to figure out how big the plume is, where it is and what it is made of, said Christopher Reddy, director of the Coastal Ocean Institute at Woods Hole Oceanographic Institution.

“The technology that we’re bringing to bear is perhaps more suited to interrogate the size, shape and chemical composition of those plumes than what traditional oceanographers have been using,” Reddy said by telephone from St. Petersburg, Florida.

The robot, called Sentry, can be put over the side of a research vessel for 14 to 18 hours at a time, with a mass spectrometer that can “sniff for oil,” Reddy said.

CIRCLING THE PLUME

Unlike robotic vehicles that are directed remotely by computer, Sentry can change course by itself — like a bloodhound following a scent — to track oil, gas or other hydrocarbons leaking from the sea bottom, Reddy said.

The Sentry AUV (autonomous underwater vehicle) is on the research vessel Endeavor, a 184-foot (56-meter) oceanographic ship owned by the U.S. National Science Foundation and operated by the University of Rhode Island.

Reddy is among some 30 scientists and crew who plan to set off from the Florida Gulf coast on Thursday for the area near the spill, focusing on the so-called southwest plume that has been seen about 20 miles south of the wellhead.

Instead of sensors dropped over the side of boats almost like fishing lines, which can observe only a small portion of the plume, Sentry would move around on its own to circle the oil, move up and down or go through it.

“At the end of the day, we’ll have a three-dimensional, almost holographical image of the plume,” Reddy said.

The hastily arranged voyage has meant packing lots of scientific equipment and other supplies aboard Endeavor to make the most of the 10 days to be spent in the area of the spill, Reddy said.

One logistical issue is fresh water. Vessels like Endeavor usually can purify sea water for drinking and other uses, but that is impossible in the spill area. The ship could go outside the spill site or even dock to get fresh water, but that would mean less time for observation. Instead, Reddy said, water will be rationed.

More information about Sentry is available online here

(Editing by Xavier Briand)

TIMELINE – Major offshore accidents in the global oil industry

An offshore gas drilling platform sank off the coast of Venezuela on Thursday, less than a month after a rig sank off the coast of Louisiana and left thousands of barrels of crude oil gushing into the Gulf of Mexico.

The accidents, particularly the Horizon spill, may lead to more scrutiny over offshore and deepwater oil drilling, which many energy analysts consider crucial to the world’s future supply of crude oil and natural gas.

Following is a timeline of selected major offshore platform and drilling accidents in the global oil and gas industry.

1969 — A blowout at Platform A offshore near Santa Barbara, California led to a spill estimated at up to 100,000 barrels of crude oil, fouling the California coastline. The

spill led to broad opposition to offshore drilling near California, and later helped spur the creation of the U.S. Environmental Protection Agency.

1979 — The Pemex-operated Ixtoc I offshore well in the Campeche Bay of Mexico suffered a blow out, eventually spewing up to 3 million barrels of crude oil in the worst offshore spill in North American history.

1980 — Alexander Kielland, a floating platform for off-duty workers, capsized in the North Sea, killing 123 people.

1982 — The Ocean Ranger semi-submersible drilling rig sank off the coast of Newfoundland, Canada, while operating the Hibernia oil field. The accident, which occurred during a huge storm, killed 84 crew members.

1984 — A blowout on the Enchova platform operated by Brazilian state oil company Petrobras in the Campos Basin caused an explosion and a fire that led to the death of dozens of workers.

1988 — The Piper Alpha platform exploded and sank while drilling in the North Sea in a field operated by Occidental Petroleum, killing 167 workers.

1989 — U.S. drilling ship Seacrest capsized during a typhoon in the Gulf of Thailand, killing more than 90 people.

1995 — Thirteen people were killed and many injured in an explosion on a Mobil oil rig off coast of Nigeria.

2001 — The P-36 offshore production platform operated by Brazilian state oil company Petrobras was rocked by explosions killed 11 people. It sank off the coast of

Rio de Janeiro five days later, spilling some of the 10,000 barrels of fuel and crude it was storing into the Atlantic.

2005 — A fire destroyed the Mumbai High North processing platform off India’s west coast, affecting 123,000 bpd of crude production, or 15 percent of the country’s domestic output, and killing 12 people. The platform was owned by ONGC.

2007 — During stormy weather, the Usumacinta rig collided with the Kab-101 platform off the coast of Mexico, causing fuel leaks and killing 21 workers who tried to flee in life rafts in one of state oil firm Pemex’s worst accidents.

2009 — The West Atlas mobile drilling rig leaked oil and gas into the East Timor Sea from the Montara oil field near Australia, and later sank after a fire. The spill continued for months before relief wells were drilled to plug the leak, depositing millions of gallons of crude into an ecologically sensitive marine ecosystem.

April 20, 2010 — Explosion and fire on Transocean Ltd’s drilling rig Deepwater Horizon licensed to BP kills 11 workers. The undersea well has been gushing roughly

5,000 barrels (210,000 gallons/795,000 liters) per day. The oil spill could become the worst in U.S. history and threatens an environmental catastrophe along the U.S. Gulf Coast.

May 13, 2010 — A Venezuelan natural gas exploration rig sank in the Caribbean sea early on Thursday. All 95 workers on the rig were rescued and there was no gas leak, the government said.

(Complied by Alonso Soto, Brian Ellsworth and Joshua Schneyer; Editing by Lisa Shumaker)