On December 2, Chevron announced that oil and gas production had started at the Jack/St Malo project in the Lower Tertiary trend, deepwater US Gulf of Mexico.
Jack and St Malo are among the largest fields in the US Gulf and were discovered in 2004 and 2003. They are located in Walker Ridge blocks 758, 759, and 678 in more than 2,100m of water, some 435km south-west of New Orleans.
Drilled to a total depth of 8,839m (29,000ft), the Jack-1 exploration well encountered more than 350 feet (107 metres) of net oil sands pay in a Lower Tertiary Trend.
In 2005, a second well was drilled on the field by the Discoverer Deep Seas drillship, and in autumn 2006, the rig Cajun Express recorded an exceptional well test on Jack-2, which was drilled to a record total depth of 8,588m (28,175ft).
A third well was completed in November 2008. It was drilled on Walker Ridge 758.
Turning to St Malo, which is located on Walker Ridge Block 678, the discovery well drilled by the Cajun Express was drilled to a TD of 8,859m (more than 29,000ft), More than 137m (450ft) of net oil pay over a gross interval of 427m (1,400ft) was encountered.
In 2004, an appraisal well was drilled 1.6km east of the St Malo discovery. The well, previously named Dana Point, was a re-entry and deepening of a dry hole that was drilled in 2001. The re-entry was deepened to 8,810m (28,900ft).
In May 2009, Chevron awarded Wood Group subsidiary Mustang the FEED contract for a joint Jack/St Malo semi-sub production facility.
A final investment decision for the joint development of the project was approved on October 21, 2010. The $7.5billion project would comprise a trio of subsea centres tied-back to a production hub with a plated capacity of 170,000 barrels of oil and 42.5million cu.ft of gas per day, with provision to add water injection capacity of 200,000bpd.
The contract for construction of the floating platform went to Samsung Heavy Industries, in Geoje, South Korea. When completed it was transported aboard the heavy-lift ship Vanguard to the US Gulf for offloading at the Kiewit Offshore Services Ltd’s yard in Ingleside, TX, where the topsides modules were built, fitted and integrated.
Chevron awarded a contract to Cameron for the supply of subsea production systems for the first stage of the development. This covered a set of twelve 15,000 psi subsea trees, production control systems, four manifolds and associated connection systems, engineering and project management services.
Deliveries were scheduled to begin in Q3 2011 and complete in Q2 2013. Examples of other key contracts include:
Technip secured a contract in January 2011, for the engineering, fabrication and subsea installation of more than 80km (53miles) of 1.75-inch outer diameter flowlines, steel catenary risers, pipeline end terminations, manifolds, pump stations and tie-in skids.
In March 2013, Chevron said a flow test of the St Malo PS003 development well had proved successful. The flow rate was limited by testing equipment constraints but still exceeded 13,000bpd.
The well was drilled on Walker Ridge block 677 by the Transocean Discoverer Inspiration.
September last year saw McDermott International announce the successful completion of its fabrication and installation contract covering fabrication and installation of 21 high-spec flowlines, manifolds and pump jumpers. Also installed were flying leads, subsea pump stations, umbilicals, and complex umbilical end terminations.
Phase one development of Jack/St Malo is expected to deliver up to 94,000bpd of oil and 21million cu.ft per day of gas.
With a planned production life of more than 30 years, current technologies are anticipated to recover in excess of 500million oil-equivalent barrels. Successive development phases, which could employ enhanced recovery technologies, may enable substantially increased recovery at the fields.
Chevron has a working interest of 50% in Jack, with co-owners Statoil (25%) and Maersk Oil (25%). Chevron holds a 51% stake in St Malo with co-owners Petrobras (25%), Statoil (21.5%), ExxonMobil (1.25%) and Eni (1.25%).
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