A multimillion dollar contract for design, supply and delivery of an ultrafiltration (UF) system and a sulphate-removal package (SRP) for offshore oilfield exploration in Angola has been won by UK-based VWS Westgarth, a subsidiary of Veolia Water Solutions & Technologies.
The two treatment units are being designed for Daewoo Shipbuilding & Marine Engineering Co’s floating production storage and offloading vessel (FPSO) in the Cravo-Lirio-Orquidea-Violeta fields. Project completion is expected in January 2012.
VWS Westgarth previously completed two projects offshore Angola in 2008 for Saipem’s FPSO Gimboa and SBM’s FPSO Saxi-Batuque.
The UF and SRP packages will be installed on the FPSO deck to provide the necessary seawater treatment for subsea well injection. The UF pretreatment step will have a capacity of 66,208 m³/d and the sulphate-removal package will treat 59,496 m³/d.
The fine filtered seawater (nominally 0.01 µm) from the UF system provides a significant weight/footprint reduction and improved water quality compared with multi-media seawater filtration technology.
The SRP removes sulphates and other divalent ions from injection water to enhance oil recovery using Dow Filmtec membranes. The removal of these ions reduces the tendency of barium sulphate and strontium sulphate scale to form in the reservoir.