Siemens Walnut Shell Filters Redesigning for Offshore Use Michael Howdeshell Chad Felch Eric Lorge
Geography -Siemens -O&G offices Slide 2
Slide 3 Agenda Walnut Shell Technology Background Testing in North Sea Taking Walnut Shell Technology Off-Shore
Slide 4 Water Treatment in Oil Field Industry Produced Water Primary Separation Hydrocyclone API Separator Plate Separator Skimmer Secondary Separation Dissolved Air Flotation (DAF) Dissolved Gas Flotation (DGF) Induced Gas Flotation (IGF) Tertiary Separation Walnut shell filter Coalescing filter Cartridge filter Sand filter
Efficiency Separation Technology Spectrum Membrane 3º Walnut Shell and Coalescing Filters 2º DAF, IGF, DGF CPI 1º Centrifuge Hydrocyclone API 1 10 100 1,000 10,000 Slide 5 Oil in Water Concentration (ppm)
Slide 6 How Do Walnut Shell Filters Work Continuous pressurized media bed Bed(s) cycle based on time or ΔP Media is recharged using backwash cycles Oil is adsorbed not absorbed Used to removed SS and free oil Walnut shell media have an equal affinity for oil and water Very low attrition rate
Slide 7 The Siemens Walnut Shell Filter Media The Black Walnut Shell Excellent surface characteristics for Coalescence Filtration High modulus of elasticity Chemical free oil separation
Walnut Shell Global Usage - Installation - Void regions Slide 8
Pilot Testing BP Valhall Platform Objectives Prove walnut shell media can handle North Sea produced water Test efficiency of system Suitable for off-shore? Bergen Stavanger Oslo BP Valhall Slide 9
Slide 10 Pilot Unit Used on BP Valhall Platform
Slide 11 Walnut Shell Media Close-ups
Slide 12 Backwash Procedure Used in Test
Slide 13 Results from Pilot Testing * * Measurements conducted with TD500 OiW analyzer
Inlet oil (ppm) Effluent oil (ppm) Results from Pilot Testing Inlet and Effluent Oil Concentrations 70 5 65 4 60 3 55 2 50 1 45 0 8/21/2008 8/22/2008 8/23/2008 8/24/2008 8/25/2008 8/26/2008 Slide 14
Results from Pilot Testing Oil Removal Efficiency 100 98 96 94 92 90 88 86 84 82 80 8/22/2008 8/23/2008 8/24/2008 8/25/2008 Slide 15
Slide 16 Moving from On-Shore to Off-Shore Demonstration Objectives Prove walnut shell media can handle North Sea produced water Test efficiency of system Suitable for off-shore use? Off-shore challenges Footprint and weight reduction Simplify and optimize backwash system
Slide 17 Moving from On-Shore to Off-Shore Tasks Reduce external scrubbing Increase throughput Reduce backwash water volume
Slide 18 Siemens Internal Backwash
Forward Flow Used for Backwash (%) Improvements for Off-Shore Complete turn over and mixing of the media Fully fluidize the walnut shell bed No rotating equipment or moving parts The ability to use a finer walnut shell media to improve oil and solids removal Smaller footprint and weight A reduction in backwash water volume 5% 0.72% 0.35% Slide 19 Sand Filter Old WSF New WSF
Slide 20 The Siemens Walnut Shell Filter Design Considerations Ready for off-shore use Refinement of the design through many years of successfully commissioned installations, most of which still in operation today Direct experience of many applications for which walnut shell filters can be appropriate No compromise of design to ensure effluent quality is maintained
Slide 21 Summary Walnut Shell Media Efficiently remove oil from North Sea produced water Solids do not impact the efficiency Suitable for off-shore use Walnut Shell System Reduced footprint through efficient backwash design and finer shell media Reduced weight Reduced backwash water volume
Slide 22 Thank you for your attention!