Page 60: of Offshore Engineer Magazine (Oct/Nov 2013)

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Subsea

Shallow water subsea systems improve NPV in production as the current produc- Shallow water subsea systems can be an ideal solution tion is now lost. If the new target for improving marginal feld net present value. Jerry Streeter, doesn’t produce as expected, reduced Field Development Manager, for FMC Technologies, Inc., explains.

production could be the net result. A second option is to install a wellhead ery little has been published develop. Shallow water systems, run platform over the new well’s bottom recently on shallow water on 11-7/8 or 16-in. high pressure drill- hole location and drill a vertical well. subsea production systems ing risers using mudline suspensions A third option is to modify the plat-

V (SWSPS) even though they were the systems or 13-5/8-in. wellheads, are form to support new well conductors. foundation used to develop deepwa- specifcally designed for wells drilled These options avoid the lost revenue ter subsea systems. The large number from jackup drilling rigs. Their func- associated with abandoning a produc- of SWSPS in place worldwide and tionality and lower costs make them ing well, but they do incur the costs of their many years of successful opera- ideal for smaller, short-life felds. building a new platform or modifying tion demonstrate the reliability that To fully appreciate the impact that a the existing platform and a delay in can be obtained with this equipment. shallow water subsea system can have getting production on stream while the

SWSPS are now being seriously on a feld’s economics it is necessary to platform – or platform modifcations, considered and installed by operators understand how a shallow water sub- are designed, fabricated, and installed. of all sizes (fully integrated, indepen- sea system reduces costs and shortens Even if the platform has an open slot, dents, and national oil companies) to time to frst production. reaching the stranded reserve could boost mature feld production rates entail drilling an expensive highly by exploiting the reserves in close deviated well, which could also be an

Drilling and completion proximity to existing infrastructure The frst option usually considered for extended reach well. that were previously considered developing stranded reserves is to drill A fourth option is to use a shallow uneconomical. additional wells from the existing plat- water subsea production system. As in

In cases where the reserves are in form. Often the challenge of this option the wellhead platform case the well’s less than 130m of water and located is that the platform slots are full, so to surface location is directly over the within 10km of the processing facility, drill a new well one of the producing bottom hole target location. This verti- subsea production systems specifcally wells would have to be plugged and cal, or slightly deviated well, reduces designed for shallow water could make the well sidetracked to the new target; drilling time and expense, as well as the reserves economically attractive to taking this action lowers the net gain the cost of modifying the platform, and

FMC Technologies’

JXT-3 shallow water subsea tree was installed on a two-slot template.

Template and trees were installed by the drilling rig.

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