Oryx Energy Co., Dallas, and a unit of Consolidated Natural Gas Co., Pittsburgh, will install the Gulf of Mexico's first Spar oil and gas production system.
Site for the 50-50 venture between operator Oryx and CNG Producing Co., New Orleans, will be on the deepwater Neptune prospect on Viosca Knoll Block 826, defined with the aid of 3D seismic technology. The project lies in 2,000 ft of water, about 65 miles east of the mouth of the Mississippi River and 80 miles south of Mobile, Ala.
Productive capacity of the floating unit, under design by Oryx will be 25,000 b/d of oil and 30 MMcfd of gas. Construction will begin early next year, with start of production expected early in 1997.
The 700 ft long, cylindrical Spar will have a diameter of about 72 ft and be topped with a deck measuring 100 ft by 130 ft. It will be towed to the site, turned on end, and anchored to the seabed with cables.
Viosca Knoll 826 will be developed in phases. CNG expects its share of Phase 1 cost to be $100-120 million in an operation that may ultimately cover four blocks: Viosca Knoll 825, 826, 869, and 870.
CNG has added 190 bcf of gas equivalent to its reserves from the field this year, making it the largest single addition to reserves in the company's history.
Use of the Spar as a production platform will save money and provide flexibility for future development, CNG said. Because of the Spar's design, it can be moved to another location in the future.
CNG pointed out that Spars are used in the North Sea for other purposes. But this is the first time one will be used in the Gulf of Mexico and as a production platform.
"EXCITING SHIP"
George A. Davidson Jr., Consolidated Natural chairman and chief executive officer, called Viosca Knoll 826 "an exciting step forward that keeps us among the leaders in exploration and production in the Gulf of Mexico."
He said, "We expect that a third of our gas and oil production will come from the deepwater Gulf by the end of the decade because of Viosca Knoll 826 and other projects we have under way or are pursuing. 51
CNG's first deepwater project in the Gulf of Mexico, a Shell Offshore Inc. combine's Popeye field development, was announced in 1992. That project, in which CNG holds a 37.5% working interest, is to begin production late in 1995. Site is in 2,100 ft of water on Green Can on Blocks 72, 73, 116, and 117.
CNG entered the Viosca Knoll project in 1993, 5 years after the first discovery well was drilled on the prospect. Oryx-CNG drilled two wells this year that proved enough reserves to proceed with development via Spar.
David P. Hunt, president of CNG Producing, said, "Using new 3D seismic data, our development team postulated that one of the field pays extended farther downdip and the sand got much thicker in an off-structure position. That well, Oryx 6 Visoca Knoll 826, found over 125 ft of net oil pay in one sand-more than double what had been mapped previously.
Copyright 1994 Oil & Gas Journal. All Rights Reserved.
Issue date: 11/21/94
