Client: Total E&P Angola

Process: Sulphate Removal

Country: France and Angola

Contract Description: Supply of membrane plant for sulphate removal

Contract Date: December 2007

Contract Completion Date: May 2008

Capacity: 301,900 BPD (48,000m3/day)

Sea Water Conversion: 75%

Sea Water Feed Quality: 36,000 mg/l (tds)

Fresh Water Output Quality: £ 40 mg/l sulphate


Project Description:

The Project is for the design and supply of a seawater treatment plant sized for 301,900 BPD (48,000 m3/day) of low sulphate water for FPSO Pazflor, which will operate in the Block 17 Field, offshore Angola.

Project Scope:

The Project scope consists of a multi-skid arrangement comprising: Membrane Filtration pre-treatment system, HP Feed Pumps, Sulphate Removal Membrane System, Chemical Cleaning System, two off Vacuum type Deaeration Towers, Vacuum Pump Skid, Control Valves and Instrumentation.A Wash Water System is also provided, sized for 19,620 BPD (130 m3/h).

Process Description:

Pre-treatment of the feed seawater is achieved by a membrane filtration system providing filtration down to 0.1µm prior to the membrane trains, thereby removing most species leading to SRP fouling.The pre-treatment filtration system supplies feed water for four (4) trains.

The conditioned water, boosted to the required feed pressure, enters the Sulphate removal trains. Each membrane train is fitted with pressure vessels containing SR90-440i nanofiltration elements.A recovery of 75% is achieved by a 2:1 brine staged configuration. Brine reject from the process is discharged overboard, while the low Sulphate permeate is routed to two 50% duty vacuum deaerators complete with a vacuum pump skid. A dedicated clean in place (CIP) package, consisting of cleaning tank, pump, heater and cartridge filter vessel is provided for SRP and SWRO membrane cleaning purposes.A dedicated clean in place (CIP) package is provided for the membrane pre-treatment filtration system. A SWRO package plant is provided to supply wash water for the main process plant complete with its own HP feed pumps.