US major Chevron is firming up its plans for a new ultra-deepwater Lower Tertiary production hub in the US Gulf of Mexico, with a semisubmersible platform the likely development option for the facility.

The company’s two discoveries Buckskin and Moccasin in the Keathley Canyon area have previously been flagged up by the operator as a potential co-development, much along the lines of its ongoing Jack-St.Malo project in the Walker Ridge area.

But Chevron now has the two fields firmly pencilled in as a hub concept opportunity, having carried out pre- FEED studies, with additional appraisal wells to be drilled this year to help firm up the reservoir’s performance potential. Drilling of an appraisal on Moccasin (which it operates with a 43.8% stake) was put on hold earlier this year for equipment repairs.

The company’s latest presentation clearly shows a semisub production platform as the concept for Buckskin-Moccasin, which it describes as one of its major offshore capital projects, alongside others such as Rosebank (west of Shetland) and Hebron (offshore Canada).

The two fields are located in the south-east portions of Keathley Canyon Blocks 872 and 736 respectively, approximately 45 miles west of the Jack field. They lie in a water depth of nearly 2,134 m (7,000 ft), and both are in the prolific Lower Tertiary trend in the GoM.

Chevron has also previously stated that Jack-St. Malo – a US $7.5 Bn semisub host production facility due onstream next year also in the Lower Tertiary and in a similar water depth – is acting as something of a design template for future similar deepwater developments.

Buckskin-Moccasin is expected to utilise many of the lessons being learned on Jack-St. Malo, for which its semisub facility has a design capacity of 177,000 boe/d.

DI hears Chevron may well go down the ‘design one, build two’ route with Buckskin-Moccasin, which could be good news for Samsung Heavy Industries, which built the 56,000 metric tonnes Jack-St.Malo hull before it was transported to the Kiewit yard in south Texas for the topsides modules to be installed.

The Moccasin discovery well hit more than 116 m (380 ft) of net pay, with Chevron’s partners being BP (43.75%) and Samson Offshore Company (12.5%). The Buckskin discovery well encountered more than 91 m (300 ft) of net pay. Chevron holds a 55% stake as operator, with its partners being Maersk Oil (20%), Samson (12.5%) and Repsol (12.5%).

Offshore