By OGJ editors
HOUSTON, Oct. 28 -- Santos Ltd., operator of Mutineer-Exeter oil fields in the Carnarvon basin off Western Australia, gave Modec Inc. a letter of commencement Oct. 16 to begin development activities. Santos and its partners had received formal approval Oct. 14 to develop the fields.
Mutineer-Exeter lies within Exploration Permit WA 191-P in the Carnarvon basin, 150 km north of Dampier. Total field reserves currently are estimated at 55 million bbl proven, 101 million bbl proven and probable, and 169 million bbl proven, probable, and possible. Santos said capital expenditure for development would be $480 million (Aust.).
Under terms of its selection Tokyo-based Modec will supply a 930,000 bbl, turret-moored floating production, storage, and offloading (FPSO) vessel, which it will convert from an existing double-hull Suezmax tanker. Turret mooring allows FPSO production facilities to be disconnected quickly from the vessel in the event of a sudden storm.
Modec will provide engineering, procurement, construction, installation, and commissioning for the vessel, including topsides processing equipment and inboard turret mooring system, and will operate the production vessel for a minimum of 5 years.
The FPSO, to be installed in 156 m of water, will have 100,000-120,000 b/d oil processing capacity with provision for a gross liquids throughput of up to 140,000 b/d.
First oil from the field is scheduled for mid-2005, but Modec said its goal is to start producing in first quarter 2005.
The mooring systems for the FPSO and the subsea infrastructure will be installed in first quarter 2004 prior to the vessel's arrival at the field. Each of the fields will have subsea production manifolds with a combination of multi-phase seabed pumps and downhole electric submersible pumps that will provide flexibility to manage production targets with varying aquifer support.
Drilling
Development drilling also is slated to begin in first quarter 2004. Initial development will include as many as five wells at Mutineer and two at Exeter. Provision will be made for a total of as many as nine wells at Mutineer and five wells at Exeter. These wells will be drilled horizontally through the reservoirs for as much as 500 m to aid recoverability.
Additional near-field drilling opportunities have been identified and evaluated for future exploitation, Santos said. These can be tied in to the planned facilities to extend the fields' life if they prove commercially successful.
Initial production is expected to be 70,000-80,000 b/d of oil, building to 100,000 b/d. Total production is forecast at 13.8 million bbl in 2005 and 35 million bbl in 2006. Reserves and production rates will be confirmed during development drilling, however, Santos said. The fields are estimated to have a production life of 7 years.
"Santos' share of peak oil production from Mutineer-Exeter in 2006 will be comparable with Santos' total oil production from all fields of 12 million bbl last year," said Managing Director John Ellice-Flint.
Santos is the operator with a 33.4% interest, and its partners are Kufpec Australia Pty. Ltd. 33.4%, Nippon Oil Exploration 25.0%, and Woodside Petroleum Ltd. 8.2%.
Mutineer-Exeter history
The Mutineer Exeter oil discovery is contained within sandstone of the upper Angel Formation, which is highly productive in Wanaea, Cossack, and Lambert oil fields, 15-40 km south of Mutineer-Exeter.
The first commercial oil discovery in the current area of EP WA 191-P was Norfolk-1 in March 2002, which encountered a 15 m oil column in Mutineer field. Subsequent follow-up appraisal wells were Norfolk-2, Mutineer-2, and Mutineer-3.
A second oil field was discovered in the permit in April 2002 with the drilling of exploration well Exeter-1, which intersected a 23 m oil column. Subsequent appraisal wells were Exeter-2 and Exeter-3.
The gross oil column is 60 m in both Mutineer and Exeter fields.
Mutineer Exeter oil is a light, 43° crude with a low gas-oil ratio of 7-12 scf/bbl. The highly fluid oil should enable good field recoveries, Santos said, and initial results indicate that each well in Mutineer and Exeter fields will have the capacity to produce 10,000-25,000 b/d.
