Chissonga FPSO takes a leap in size

Target: Maersk Oil chief executive Jakob Thomasen

Danish independent Maersk Oil is set to issue bid documents in October covering all the elements of its super-sized Chissonga project in deepwater Block 16 off Angola, which will involve about 40 subsea wells tied back to a floating production, storage and ­offloading vessel.

Industry sources said invitations to tender will be released for an FPSO which will be designed to handle upwards of 150,000 bpd of oil, at least 50% bigger than the vessel Maersk was envisaging just one year ago.

This uptick in size has been driven by drilling success in Block 16 where sources said a well test is currently under way on the Caporolo-1 probe after the operator recently completed the Chissonga-3 appraisal well.

Nils Smedegaard Andersen, chief executive of parent company AP Moller-Maersk, added last week in the company’s quarterly results: “We still have some appraisal drilling to do and that may affect the scope of the project.” Currently, the vessel is expected to handle some 200,000 bpd of water and 235 million cubic feet per day gas, both for injection purposes.

One floater source described it as a huge unit on the scale of Total’s Girassol FPSO in adjacent Block 17.

The Girassol floater, hosting a 20,000-tonne deck, was built from scratch in South Korea.

However, while Maersk is still considering a newbuild for Chissonga, most sources contacted by Upstream said the Danish player is leaning towards a converted unit.

The base-case design calls for a tanker conversion but a newbuild has not been ruled out, said one source.

BW Offshore, Modec and SBM are expected to chase the FPSO supply contract with contract award scheduled for the first quarter of next year.

It is currently unclear if Maersk will kick-start the tender process with a short design competition before inviting one bidder to submit a commercial bid.

The FPSO, which has been in pre-front-end engineering and design phase for over one year, will require a VLCC-size hull.

Maersk is understood to be looking at a spread-moored configuration with catenary anchor leg mooring for offloading oil because the field’s gas pressure — 7500 psi, said one source — is deemed too high for a turret with swivels.

All gas is owned by Angola’s government so while Maersk may initially re-inject it, the gas is likely to be exploited as feedstock for liquefaction plants in Cabinda.

Bruce Laws, president of Maersk Oil in Houston, said at least one more appraisal well is to be drilled at Chissonga this year before a development plan is finalised. He confirmed Maersk will carry out design and project management of the FPSO from Houston and that Chissonga is in its pre-FEED stage.

FEED work was expected to start last year but was repeatedly pushed back.

Doris Engineering’s Houston office has been carrying out engineering work on Chissonga for two years running, with one source indicating the French contractor is on a rolling monthly contract.

Sources said they expect Doris to stay on as a consulting engineer for project management.

Maersk is increasing staffing levels for the project in its Houston offices, including an increasing number of engineers from Doris.

“Some of their people are just integrated into our team,” Laws said of Doris’ presence.

Invitations to tender, said subsea sources, are also expected to be released in October for the project’s subsea production system and its umbilical, riser and flowline equipment.

Chissonga lies in about 1500 metres of water in the northwest of Block 16 and is due on stream in 2016.


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