1.
Water Technologies
Walnut Shell Filters
Siemens Water Technologies
Redesigning for Offshore Use
Michael Howdeshell
Chad Felch
Eric Lorge

2.
Slide2
Water Technologies
Geography
-Siemens
-O&G offices

3.
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Water Technologies
Agenda
Walnut Shell Technology Background
Testing in North Sea
Taking Walnut Shell Technology Off-Shore

4.
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Water Technologies
Produced
Water
Water Treatment in Oil Field Industry
Tertiary Separation
 Walnut shell filter
 Coalescing filter
 Cartridge filter
 Sand filter
Secondary Separation
 Dissolved Air Flotation (DAF)
 Dissolved Gas Flotation (DGF)
 Induced Gas Flotation (IGF)
Primary Separation
 Hydrocyclone
 API Separator
 Plate Separator
 Skimmer

5.
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Water Technologies
Separation Technology Spectrum
10,0001,000100101
Oil in Water Concentration (ppm)
Efficiency
API
CPI
DAF, IGF, DGF
Hydrocyclone
Centrifuge
Membrane
Walnut Shell and
Coalescing Filters
1º
2º
3º

6.
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Water Technologies
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

7.
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Water Technologies
The Siemens Walnut Shell Filter Media
The Black Walnut Shell
 Excellent surface characteristics for
 Coalescence
 Filtration
 High “modulus of elasticity”
 Chemical free oil separation

8.
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Water Technologies
Walnut Shell Global Usage
- Installation
- Void regions

9.
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Water Technologies
Pilot Testing – BP Valhall Platform
Objectives
 Prove walnut shell media can handle North Sea
produced water
 Test efficiency of system
 Suitable for off-shore?
Stavanger
Bergen
Oslo
BP Valhall

10.
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Water Technologies
Pilot Unit Used on BP Valhall Platform

11.
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Water Technologies
Walnut Shell Media Close-ups

12.
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Water Technologies
Backwash Procedure Used in Test

13.
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Water Technologies
Results from Pilot Testing
*
* Measurements conducted with TD500 OiW analyzer

14.
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Water Technologies
Results from Pilot Testing –
Inlet and Effluent Oil Concentrations
45
50
55
60
65
70
8/21/2008 8/22/2008 8/23/2008 8/24/2008 8/25/2008 8/26/2008
Inletoil(ppm)
0
1
2
3
4
5
Effluentoil(ppm)

15.
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Water Technologies
Results from Pilot Testing –
Oil Removal Efficiency
80
82
84
86
88
90
92
94
96
98
100
8/22/2008 8/23/2008 8/24/2008 8/25/2008

16.
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Water Technologies
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




17.
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Water Technologies
Moving from On-Shore to Off-Shore
Tasks
 Reduce external scrubbing
 Increase throughput
 Reduce backwash water
volume

18.
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Water Technologies
Siemens Internal Backwash

19.
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Water Technologies
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
0.72%
0.35%
5%
Sand Filter Old WSF New WSF
ForwardFlowUsedfor
Backwash(%)

20.
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Water Technologies
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

21.
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Water Technologies
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

22.
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Water Technologies
Thank you for your attention!