Client: SBM Offshore
Process: Sulphate Removal
Country: Santos Basin Offshore Brazil
Contract Description: Seawater Treatment and Utility Modules
Contract Date: February 2012
Contract Completion Date: August 2013
Capacity: 201,060 BPD (31,970 m3/day)
Sea Water Conversion: 75%
Sea Water Feed Quality: 35,177 mg/l (TDS)
Product Water Output Quality: <40 mg/l sulphate
The project is for the design, procurement and supply of equipment with the provision of construction technical assistance for a sea water treatment plant sized for 201,060 BPD (31,970 m3/day) of low sulphate water and utility support systems for the Cidade de Ilhabela (Tupi 4) FPSO, which will operate in the Santos Basin, offshore Brazil.
The scope consists of two modules; one module for sea water treatment plant comprising Coarse Strainers, Multi Media Fine Filtration, Upstream Vacuum Deaerator Package, HP Feed Pumps, Guard Cartridge Filters, Sulphate Removal Membrane System, Clean In Place System, Chemical Dosing Systems, Piping, Valves and Instrumentation and a second utilities module comprising Cooling and Heating Medium systems, Instrument Air and Nitrogen Gas storage receivers, Water Injection Pumps, Piping, Valves and Instrumentation.
Coarse filtration of the feed water is provided by a set of basket coarse strainers rated at 500µm. Fine filtration is then achieved by a set of multi media fine filters, complete with air scour, followed by a set of guard cartridge filters to provide fine filtration down to 5µm prior to the membrane trains. The set of fine filters supplies feed water for two (2) SRP trains.
The conditioned water is routed to a vacuum deaerator package then forwarded to the sulphate removal trains. Each membrane train is fitted with pressure vessels containing a combination of SR90HR-440i and SR90-440i nanofiltration elements to achieve the required low sulphate permeate quality. 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 forwarded onwards to the water injection pumps for injection to the wells at the required pressure. A dedicated clean in place (CIP) package, consisting of cleaning tank, heater, pump and cartridge filter vessel is provided for membrane cleaning purposes. Chemical Dosing systems for the SRP system are also provided.
The cooling medium system comprises an expansion vessel, circulating pumps, an in-line fine filter and plate heat exchangers. The heating medium system comprises an expansion vessel, circulating pumps and an in-line coarse filter. An instrument air receiver and a nitrogen gas storage vessel provide the necessary utilities to the modules and other ship wide systems.