An energetic undertaking
Oil companies are sparing no expense in search of reserves 1,000 feet or more below the surface of the Gulf of Mexico.
By ASSOCIATED PRESS
Published June 22, 2006
ABOARD THE DISCOVERER DEEP SEAS - Nearly three football fields long, the ship appears to be sitting idle on the turquoise blue waters of the Gulf of Mexico, perhaps even abandoned.
Beneath the deck, there's no such tranquility. A 200-person crew of geologists, engineers and technicians works around the clock at dimly lit keyboards, controlling every move of an adjoining oil rig as it uses a 16½-inch pipe to bore through the ocean floor to a depth of more than 5 miles.
The Chevron Corp. crew is developing a deepwater oil field 190 miles off the Louisiana coast that's projected to produce 100,000 barrels of oil a day by 2008 and 500-million barrels overall.
It's the kind of discovery once thought to be out of reach, but with improved technology and climbing global oil prices, companies are spending billions developing oil fields the Interior Department says will boost gulf production.
Deepwater exploration - done in water at least 1,000 feet deep - is also volatile, as companies face increasing development costs, a battle with the federal government over royalty payments and continued rig shortages. And Hurricanes Katrina and Rita illustrated a threat that curbed deepwater exploration in addition to damaging 113 rigs and temporarily shutting down 28 percent of the nation's refining capacity.
When Chevron begins producing oil from this reservoir called Tahiti, it will be among several new major oil and natural gas projects in the gulf over the next two years.
Even with the risk of hurricanes, companies say it's a safer investment than politically charged climates in Latin America and West Africa.
This past weekend, key U.S. House members reached a landmark deal to allow oil and drilling as close as 100 miles to shore, closer if states permit it. The committee's plan could be voted on by the full House as early as next week.
Chevron produced the biggest gulf discovery last year, with a 34,189-foot well about 170 miles southeast of New Orleans and about 20 miles from the Deep Seas ship. Chevron, the largest leaseholder in the gulf, has also drilled in the greatest water depths, at 10,011 feet.
Chevron's focal point for now is drilling on the Deep Seas, a vessel owned by Houston-based Transocean Inc., and one of six deepwater ships operating in the gulf.
Outnumbered almost five to one by the traditional rigs drilling in the gulf, the ships are not your ordinary drilling machines.
The Deep Seas positions itself above the well site and sits virtually still, thanks to six 13½-foot propeller thrusters beneath the hull.
The thrusters help the ship withstand 20-foot waves, 80 mph winds and currents that would prevent traditional rigs from operating. The amount of power used to keep the ship stationary and drilling would light 40,000 homes.
The ship is connected to the gulf's floor by 4,300 feet of metal casing that surrounds the pipe and is fastened to the sea floor by a valve, which helps prevent accidents and contamination.
Crews on the ship work at computer screens and control panels to push the pipe and a drill bit into the ground about 80 feet per hour. An unmanned mini-submarine is used to collect sediment samples on the sea floor and monitors drilling progress.
Drilling starts by setting a 36-inch diameter steel casing about 300 feet into the seabed. Smaller casing gets connected until the well resembles an inverted extended telescope. It takes more than 1-million pounds of pipe to complete a well.
The entire process takes place in water pressure reaching 20,000 pounds per square inch and temperatures hitting 400 degrees.
"Drilling 3,000-foot land wells vs. 28,000 feet in the Gulf of Mexico is like flying a Cessna vs. flying the space shuttle," said Curt Newsome, Chevron's senior drilling superintendent. "You're drilling something that's 5 miles away, and all you have are indicators to look at. You can't see down there, but you have to figure out what's going on."
For now Chevron plans six wells, each taking about three to four months to complete. Once Chevron has finished drilling, it will link the wells to a production platform being built in Finland.
The project costs about $3.5-billion, including about $500,000 a day in crew and drilling-related costs. Significant delays from inclement weather or drilling mistake can double or triple the daily costs.
infobox: OIL ROYALTIESSeveral major oil companies said Wednesday they are willing to discuss with the Interior Department changes in offshore drilling leases containing a government error that could give the industry a $10-billion windfall. But other companies, including Exxon Mobil Corp., said that while they are ready to work with the government on the issue, they oppose changes in the leases, issued in the late 1990s. The error in the 1998-99 lease contracts for deep-water drilling in the Gulf of Mexico, could cost the government $10-billion in lost royalty payments given the current price of crude oil and natural gas, according to an analysis by the Government Accountability Office, Congress' auditing agency.