Prosernat supplying major Angola, North Sea projects, designing G-T-L technology

Prosernat supplying major Angola, North Sea projects, designing G-T-L technology

Prosernat has supplied two glycol contac tors and one common glycol regenera tion skid for the Girassol FPSO offshore Angola. Total design gas flow rate through the contactors is 8.8 million cu meters/day at 43° C and 55 bar. The lean glycol flow rate (concentration of 99.85% weight) is 6 meters/joule, which results in a dry gas water dew point of -16°C at 55 bar.

The gas dehydration unit has been designed to take into account the roll and pitch of the FPSO, so much that the required dry gas dew point is achieved regardless of the barge motions. Prosernat has developed special internals designed to minimize the effect of sea motion which are already in operation in various other floating production units, including Jotun and Troll C in the North Sea.

In The Norwegian North Sea, the Gullfaks C platform operated by Statoil is being modified this year to sustain oil production and to increase gas output. This will be achieved via a new module for separation, gas dehydration and methanol injection. Aker Maritime was nominated as main EPC (engineering, procurement, construction) contractor - in July 1999 it awarded to Prosernat both inlet separator and gas dehydration packages for the Gullfaks C module to be assembled at Aker McNulty in Newcastle.

Both orders had the same challenging delivery time of 34 weeks despite high technology content and material selection like duplex steel for high-pressure vessels. The separator was designed with cyclone technology to handle 90,000 b/d of crude oil, leading to a 2.6 meters ID by 7 meters T/T vessel weighing 40 tons. The gas dehydration package was designed to treat 320 MMcf/d of gas with a dewpoint of -17°C at contacting pressure, and included a 11 MW inlet cooler, an inlet scrubber based on cyclone technology, a glycol contactor and the skid-mounted glycol regeneration package. This package had a footprint of 5 meters wide and 8 meters long with a weight of 60 tons.

In February this year, Prosernat delivered to Aker McNulty workshop all items, meeting the challenge of shortest delivery ever done for this type of unit and enabling Aker Maritime to tie in the separator and gas dehydration packages in the Gullfaks C module on schedule.

Elsewhere, Prosernat is hopeful of winning contracts this year for its Drizo gas dehydration process in the Timor Sea and offshore Vietnam. It is also working with ENI to develop a pilot gas-to-liquids conversion plant, based on the Fisher Tropsch process. This could be adapted in time for deepwater application.

More in Home