Gulf of Mexico

Houston-based Mariner Energy founded its entry into the deepwater Gulf of Mexico on the walk-before-you-run principle and aimed at progressively more challenging projects, including the Pluto development. Dave Huber, Mariner's Director of Deepwater Development, called the Pluto project, located in Mississippi Canyon 673, 674, 717, and 718, "difficult."

High pressure, long tieback a challenge for Pluto project

Houston-based Mariner Energy founded its entry into the deepwater Gulf of Mexico on the walk-before-you-run principle and aimed at progressively more challenging projects, including the Pluto development. Dave Huber, Mariner's Director of Deepwater Development, called the Pluto project, located in Mississippi Canyon 673, 674, 717, and 718, "difficult."

"The biggest challenges we faced were the flow assurance issues," he said.

The well is in 2,900 ft of water, and the well itself is 23,000 ft deep. Add to that high pressure, a 70 degree angle, and a 28.4 mile subsea tieback, and you have "a very difficult project," Huber said. "We were also concerned about the water pressure."

Mariner seriously considered using two umbilicals, but finally opted for one after a close internal vote (7-6) based on the profit versus risk scenario. "You could be a hero or a villain," he said, noting the decision reflected high potential profits, but plenty of risk. "We're very behind a single line decision."

Mariner's approach to the tough well brought theory and practice into the flow assurance team. "Subsea is unforgiving to problems," he said, adding that it's vital to have a reservoir engineer on the team. The well was also difficult from the reservoir standpoint, he said, and the project team designed for a high volume of both gas and oil.

"Subsea is the best approach to getting into deepwater," Huber said. "The future is bright in the Gulf of Mexico for long distance subsea tiebacks." Operator Mariner had a 100% interest in the Pluto project but sold a 63% working interest to Burlington Resources in June 1999. Mariner's interest will increase to 51% with Burlington's at 49% after project payout. Mariner is moving on the Anconcagua project, located in Mississippi Canyon 305 in 7,000 ft of water. The well is expected to have a 44-mile subsea tieback.

BHP continues search in Atwater area

Australian Broken Hill Proprietary (BHP) Petroleum continues to focus intently on the Gulf of Mexico exploration, following the Atlantis discovery in the Atwater Foldbelt. With a significant oil zone in Miocene sands, BHP and BP Amoco found more than 300 ft of net pay in this ultra-deepwater area. Drilling through other prospective zones is planned. Drilled by the BHP-operated C.R. Luigs, the Atlantis No. 2 well is in Green Canyon 743 in 6,675 ft water depth.

Magnum, Burlington hit Vermilion gas

Magnum Hunter Resources and Burlington Resources had two natural gas discoveries on Vermilion 84. The Vermilion 84 B-2 discovery well was completed in a Miocene sand below 11,500 ft and is flowing at 7.5 MMcf/d of gas and 200 b/d. The second recent discovery, Vermilion 84 No. A-4 ST well, was drilled from the production platform and encountered three pay sands.

Magnum Hunter owns a 16.67% working interest in the B-2 exploration well and a 16.25% working interest in the A-4 exploration well. Burlington Resources Inc. operates both wells and holds a 66.67% working interest in the B-2 exploration well and a 65% working interest in the A-4 exploration well.

Spinnaker has two High Island strikes

Spinnaker Exploration Co. said it drilled two successful exploratory wells in High Island 202. High Island 202 No. 4 was drilled to a total depth (TD) of 8,235 ft. Spinnaker operates that well with a 75% working interest (WI). High Island A-18 was drilled to a TD of 8,613 ft. Spinnaker operates the A-18 No. 1 with 100% WI. High Island A-19 No. 1, owned 100% by Spinnaker, will commence drilling upon completion of operations at A-18 No. 1.

Gunnison appraisal successful

Kerr-McGee Corp. and its partners in the Gunnison prospect appraisal well in Garden Banks 668 said drilling encountered about 350 ft of net pay. The 19,147-ft sidetrack, located in 3,150 ft water depth, found an oil column of 1,800 gross ft about 1/4 mile north of the discovery well. Partners in the project estimate reserves to be 150-250 million bbl of oil, but several more appraisal wells are planned to evaluate Gunnison's potential. Partners in the blocks are operator Kerr-McGee with 50% interest, CXY Energy Offshore with 30%, and Cal Dive International with 20%.

Falcon's Vermilion prospect confirmed

Previously estimated commercial oil and gas reserves from the Vermilion 376 No. 3 well in the Falcon prospect, offshore Louisiana, were confirmed. Operator PetroQuest Energy Inc., a 43% partner in the No. 3 delineation well, said the well was drilled to a true vertical depth of 4,489 ft, logging 59 ft of net hydrocarbon column in the S2 sand and 15 ft of net hydrocarbon column in the S1 sand. Private companies hold the remaining interest.

West Cameron 587 wells complete

Houston Exploration Co. and Devon Energy's A-15, A-16, and A-17 wells have been completed at the West Cameron 587 field. The A-15 and A-16 wells are on production and flowing about 25 MMcf/d. The A-17, which flow tested about 10 MMcf/d, will be put on production in August, and a fourth well will be drilled in August. Houston Exploration has a 64% working interest in the field. Operator Devon Energy owns the remaining 36% working interest. The three wells reportedly were drilled and completed about 20% below budget.

Spar development set for Horn Mountain

Vastar Resources awarded Aker Maritime a contract to deliver a spar floating production platform for the Horn Mountain field in Mississippi Canyon 127. Aker Maritime will be responsible for the engineering, procurement, fabrication, and delivery of the complete spar hull and mooring system. The hull will be built at Aker Maritime's yard in Finland. Project sanctioning is scheduled for the fourth quarter of 2000, with proposed delivery of the spar scheduled for the second quarter of 2002. Vastar holds a two-thirds working interest in Horn Mountain field and serves as operator, with Occidental Petroleum holding a one-third interest. The Horn Mountain field will be the fifth Gulf of Mexico deepwater field to be developed using spar technology. Located in about 1,600 meters water depth, the Horn Mountain field production is anticipated to peak at 65,000 bbl/d and 50 MMcf/d of gas.

Breton Sound farm-in

Aviva Petroleum Inc. signed a farm-out agreement on its Breton Sound property offshore Louisiana. Under the agreement the farmee, a privately held oil and gas company in New Orleans, Louisiana, has the right to drill a well to test the Hollywood formation at 16,000 ft on or before Dec. 31. Aviva owns a 65% working interest in this property and will retain its proportionate share of a 3% overriding royalty interest during payout. All costs of the well will be borne by the farmee.

Williams to receive Alabama gas

Chevron USA and Samedan Oil selected Williams to gather, process, and transport up to 115 MMcf/d of natural gas from wells along the Alabama coast. Financial terms of the agreements were not disclosed. Williams will connect the gas production to its infrastructure by installing 33 miles of offshore pipeline. Initial volumes are expected in September.

Horizon wins pipeline contract

Horizon Offshore won a contract for the Texas Deepwater Link pipeline. Horizon Offshore will construct 17.5 miles of 20-in. diameter pipeline for El Paso Energy's Tennessee Gas Pipeline Co. off the coast of Texas. The pipeline will be constructed using Horizon lay barge Lone Star Horizon. Additionally, Horizon bury barge, Canyon Horizon, will be used for deep burial in a shipping fairway. Construction is expected to begin during the third quarter of 2000.

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