1. KNOW YOUR CONTROL FLUID
Simon McManus
Technical Director
MacDermid Plc Offshore

2. MacDermid Canning Offshore Fluids Supply
NORWAY
ABERDEEN
WIGAN
HOUSTON
SINGAPORE
BRAZIL
SOUTH AFRICA
AUSTRALIA

3. Types Of Control Fluid Oil-based, synthetic hydrocarbons.
Water-based, mainly water and glycol

4. Main Properties Required By a Subsea Control Fluid
Low Viscosity
Low Compressibility
Higher SG than Seawater
Compatibility with Seawater
Environmentally Friendly
Lubrication
Corrosion Protection
Resistant to Microbiological Attack

5. Components in Water-Based Fluids
Water (Distilled)
Mono-Ethylene-Glycol (MEG)
Lubricants (Boundary)
Corrosion Inhibitors
Biocides
Surfactants/Dispersants Dye.

6. Advantages of Water-Based Fluids
Low Toxicity and High Biodegradability
Viscosity of Water
More Compatible With Seawater
Low Compressibility
Fire Resistant
SG Similar to Seawater (Slightly Higher is an Advantage)

7. Water-Based Fluids Oceanic HW 540, HW525, HW560 Oceanic HW 443, HW418
Castrol Transaqua HT, EE1, EE2
Aqualink Fluids

8. Oceanic HW 500 Series 20 Year Track Record
First Project was The Sun Balmoral
The 5 signifies 5% additives (lubricants, inhibitors etc)
The last two digits signify the glycol content.

9. Oceanic HW540 Most common fluid in the North Sea 40% MEG
Molybdenum based lubricant
Amine corrosion inhibitor
Requires antifoam during flushing
Temperature limits -25°C to 90°C

10. Trapped Air In HW540 Air Gaps HW 540
Water Vapour from the Fluid can cause Corrosion in Steel Pipes or Components

11. Over-Heating HW540 pH could fall Fluid will turn from blue to green
Small non abrasive black particles of molybdenum will drop to the bottom.

12. Heavy Seawater Contamination of HW 540
A thin layer of oily material could form on the surface
The fluid will turn from blue to green
Molybdenum and insoluble abrasive white salt sinking to the bottom.

13. Oil Contamination in HW540
Oil layer will form at around 3-4% contamination
White emulsion will form and over extended periods bacteria could grow in the oil water interface
Fluid will go cloudy
Oil that sinks in Oceanic fluids will probably be plasticiser from hose material.

14. Oceanic HW443 More tolerant to seawater intrusion
Has a Vapour Phase Inhibitor (VPI)
Contains fluorescent dye
Has a 10 year track record
First project Total Ellon/Dunbar
Temperature range -25 to 140°C
Less toxic than HW540
No antifoam required

15. Oceanic HW740 Can withstand 50% seawater intrusion Very good VPI
Contains fluorescent dye
Temperature range -25 to over 150°C
Same Lubrication as HW540
Less toxic than HW540 and also much more biodegradable

16. Vapour Phase Testing
COMPETITOR OCEANIC HW 443

17. Hydrostatic Pressure Head
WATER-BASED
HYDRAULIC FLUID
SEAWATER
HYDRAULIC OIL
Foinaven m
61.5 BAR BAR BAR
11.94 BAR BAR
Girasol 1405m
144 BAR BAR BAR
28 BAR BAR

18. Hydrostatic Pressure Head
Water-based
Oil-based

19. Seawater Migration
Start of Test min hrs days

20. Seawater Migration

21. Pressure Differentials

22. Long Umbilical Lengths

23. Long Umbilical Lengths
Pressure
1 BAR
Water-based
Hydrocarbon-based

24. Extreme Water Depth Reliability is paramount due to work-over cost.
Stability of the fluid and compatibility is essential.
Static pressure head becomes significant.