Thunder Hawk prospect could hold up to 400 million barrels
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Petroleum News Houston correspondent
A Thunder Hawk is hovering near the largest and perhaps most dynamic oil and gas discovery in the Gulf of Mexico, the BP-ExxonMobil Thunder Horse complex in deepwater Mississippi Canyon.
After two years of planning, operator Dominion Exploration & Production and partners Spinnaker Exploration and Murphy Oil have commenced drilling on their Thunder Hawk prospect on Mississippi Canyon Block 734, according to the U.S. Minerals Management Service. The exploratory well, situated in 5,724 feet of water, is being drilled from Transocean’s Cajun Express.
Thunder Hawk is believed to overlap Thunder Horse’s official borders, and is said to have a resource potential of 300 million to 400 million barrels of oil equivalent. It specifically adjoins Mississippi Canyon Block 778 on the northeast side of the eight-block Thunder Horse complex, due to launch first production next year.
Most of area leasedMost of the leases within a 15-mile radius of Thunder Horse have been scooped up by various companies over the last four years, demonstrating the area’s strong attraction to explorers. Other players in the region include Shell, ChevronTexaco, ConocoPhillips, Marathon Oil and big exploration and production independent Anadarko Petroleum.
WesternGeco, the world’s largest seismic company, is currently shopping on its website non-proprietary charts of the Thunder Horse region, covering an expansive area ranging in size up to 48 blocks, to give prospective clients “a chance to see the real shape of the biggest field in the Gulf of Mexico.”
However, because of the region’s complex geology and reservoir imaging challenges, no one is certain of Thunder Horse’s true potential. Some analysts believe the play could hold upward of 7 billion barrels of recoverable reserves, although 3 billion barrels is often cited as the likely mean.
The Boarshead basin, in the south-central part of Mississippi Canyon, houses three large geologic structures, including the one that spawned the primary Thunder Horse accumulation, the estimated 1 billion barrel Thunder Horse South field. Thunder Horse North, a separate BP discovery and part of the complex, holds additional estimated reserves of around 400 million barrels.
Seismic imaging difficult in areaGeologists say the problem with Boarshead is that all three structures within the basin, including Thunder Horse’s, are overlain by so-called “allocthonous” salt bodies, which tend to distort seismic readings and make imaging difficult.
“Resolving structural complexity and stratigraphic details through adequate seismic imaging key to the success of future development of this field,” according to one BP official.
Still, daily production at Thunder Horse is scheduled to begin next year with output of 250,000 barrels of oil and 200 million cubic feet of natural gas.
Thunder Hawk partners Dominion, Spinnaker and Murphy acquired Mississippi Canyon Block 734 in the 2000 Central Gulf of Mexico Lease Sale 175 on an uncontested bid of $2.1 million. Thunder Horse partners BP and ExxonMobil passed on the block.
Proteus Oil Pipeline and Endymion Pipeline will carry Thunder Horse oil and natural gas about 150 miles from Thunder Horse to storage facilities near New Orleans, La.