London-based Alpha Thames, a subsidiary of Saab Technologies, has introduced the latest configuration of its AlphaPRIME incremental field development process. This is effectively a two-part system that functions like a manifold but offers greater flexibility in that it can be reconfigured throughout the field's life to cope with unexpected changes in reservoir performance.
The first module is known as KeyMAN. It contains piping, ROV-operated isolation valves, multi-ported module connections, connection hubs for flowlines, and a slot to tie in integrated service umbilicals for providing power, control and chemicals. Onto KeyMAN would be fitted the other new module, called FlowCAP, which houses the controls, hydraulics, and instrumentation associated with a conventional manifold. The two modules would be connected through an industry-standard locking mechanism. When combined in this way, they would form the basis for an AlphaCPU (Central Processing Unit).
The installed FlowCAP component, once operational as an AlphaCPU system, can provide all the functions of a normal manifold. Typically, AlphaCPU would contain two FlowCAPs at the outset to provide 100% system availability. If the production profile changes, the operator has the flexibility, within the AlphaCPU, to retrofit a System-Module containing multiphase pumping or additional metering/separation facilities. The new System-Module would have been pre-tested on land, complete with electric power and control functions, prior to exchange with a FlowCAP. While one is retrieved, the other FlowCAP module would be left in place to ensure there are no interruptions to production. The removed FlowCAP can then be modified and tested onshore. The installation process would then be repeated with the remaining FlowCAP being replaced by the second System-Module.
FlowCAP/KeyMAN, Alpha Thames' new alternative concept to conventional subsea manifolds.
Alpha Thames claims that under its procedures, subsequent System-Module upgrades would be returned to the seabed site fully tested and fully functional from the outset. Replacement of components from conventional manifolds has not always gone smoothly, leading to operational problems following the production re-start.
The company is now in full project status undertaking a manufacturing qualification program of its essential electric components for 3,000-m water depth, while an AlphaCPU is being designed in preparation for retrofit onto a producing field in 2004.
For more information, contact David Appleford, Alpha Thames. Tel: +44 1708 229229, fax: +44 1708 251273, email: firstname.lastname@example.org, website: www.alpha-thames.co.uk.