FRANCE: Engineering role for Doris in four phases of South Pars

In March, TotalFinaElf and partners Gazprom and Petronas brought onstream Phases 2 and 3 of the South Pars gasfield in the Iranian sector of the Persian Gulf.

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In March, TotalFinaElf and partners Gazprom and Petronas brought onstream Phases 2 and 3 of the South Pars gasfield in the Iranian sector of the Persian Gulf. This represents the first production from the field, which is the world's biggest offshore gas accumulation, taking into account the North Field extension on the Qatari side of the median line. At $2 billion, it is also the single biggest project in Iran involving international oil companies.

Doris Engineering provided basic engineering of the development's four platforms, and basic/detailed engineering of the pipelines exporting gas and condensate to the new treatment plant in Assaluyeh, southwest Iran. This facility, extending over 150 hectares, includes four gas processing trains (ultimately with total processing capacity of 2,000 MMcf/d), export compressors, condensate stabilization and storage units, and sulfur recovery units. All the gas is fed through the Iranian domestic network, while the condensate is routed back to the Gulf for onward export through an offshore loading catenary anchor leg mooring buoy.

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The early production jackup on Soroosh/ Nowrooz will be bridge linked to the SWP1 platform.
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There are two 15-slot, unmanned wellhead platforms (WP1 and WP2) situated 10 km apart, each with an operating weight of 4,850 tons and each equipped with minimum production facilities. Two relief platforms, RP1 and RP2, are bridge linked to the wellhead platforms. Gas, condensate, and condensation water are exported untreated to Assaluyeh through two 32-in., 105 km pipelines, each with a 4-in. piggyback line. TotalFinaElf claims this is the world's largest multiphase transport system of its kind.

Doris is also the nominated subcontractor for the detailed engineering of two large wellhead platforms for South Pars 4 and 5, where Agip is the operator. The platforms in this case will be constructed by main contractor Sadra at a yard on the Gulf coast, where 2,000 people are employed. The scope of this project is likely to be a little larger than South Pars 2 and 3. The gas will also be piped to Assaluyeh.

One other current project in the Gulf is an oilfield, Sowroosh-Nowrooz, where Shell is the development operator. Here too, Doris is providing detailed engineering for the platforms and pipelines, as engineering, procurement, construction, and installation subcontractor to Hyundai Heavy Industries.

Soroosh is being developed to produce at up to 100,000 b/d from 10 horizontal wells drilled from two wellhead jacket platforms, SWP1 and SWP2. First-stage production will be catered for on the SPP1 production platform, with crude exported through a floating storage vessel. Nowrooz will have a production capacity of 90,000 b/d from 17 horizontal wells drilled from a satellite wellhead jacket platform, NWP1, and an integrated production platform, NP2. Nowrooz's reservoir fluids will be part-stabilized on the NPP2 conductor tower platform before being exported to the SPP2 treatment platform on Soroosh.

Prior to start-up of full production, an early production facility, a converted jackup, will be installed, bridge-linked to SWP1 at Soroosh. This will produce at rates of 60-80,000 b/d. There will be two 5.8 km, 16-in. pipelines for oil export. Water depth for Soroosh is 40 m, and for Nowrooz, 25 m.

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