Aibel PDF 18 Advanced Methods
Aibel PDF 18 Advanced Methods
Aibel PDF 18 Advanced Methods
Advanced Methods for Dehydration of Heavy Oils Jarle Michaelsen Manager, Separation Business Unit Vera Cruz: 19 March 2009
www.aibel.com
Outline
Introduction to Produced Water Separation What is electrocoalesence ? What is VIEC (Vessel Internal Electrostatic Coalescer) ? How does it work ? What are the benefits ?
GAS OIL
WATER
Reject Gas
Advantages :
Water
Increase production Improve level control Reduce chemical consumption Reduce fluid heating Less fresh water for desalting
Improve
What is electrocoalescence ?
The electric field creates an attractive force between water droplets. This forces them to coalesce, and thereby the settling velocity increases. Electrodes
Water droplets
2008 6
100 ml
HV AC
VIEC Performance
100 90 Separation during normal residence time (%) 80 70 60 50 40 30 20 10 0 0 20 40 60 80 100 120 Atmospheric viscosity (cP) WITH VIEC NO VIEC
VIEC will provide efficient bulk water removal in normal ranges of operational conditions. When normal gravitational separation gives some separation, the VIEC will provide more than 70% separation, usually even much better. For production separators in operation, a performance in the range from 2-8% BS&W in the oil outlet is usually achived.
Figure: Separation results of different crude oils as a function of the crude oil viscosity. Normal residence time, normal dosage of demulsifier, small droplets
VIEC wall
VIEC Block
Control room
2008
HT VIEC Block
12
ILMS
13
HT-VIEC
2008
14
LOWACC
LOWACC Wall
15
16
2008
VIEC Installations
1. StatoilHydro, Troll C - Reduced chemical cons.and increased production API 29 2. Bluewater, FPSO Munin - Increased production API 26 3. StatoilHydro, Research Center - Improved separation API 17 - 32 4. Maersk Oil Qatar, Al Shaheen - Improved separation API 22 - 28 5. StatoilHydro, Grane - Improved separation, increased production API 19 6. Petrobras, P-34 - Improved separation of heavy oil API 17 7. Petrobras, P-35 - Cleaner Produced Water from heavy oil and reduced heating API 20 8. StatoilHydro, Volve - Improved separation, salt removal API 39 9. StatoilHydro, Fram East - Increased production API 29 10. Petrobras, P-37 Improved separation API 22 11. Woodside, Vincent - Improved separation, reduced residence time API 19-21 12. StatoilHydro, Heidrun - Improved separation, Naphtenates API 25 13. StatoilHydro, Gja - Expected emulsion problems API 50 14. BP, Valhall - Emulsion problems API 39
2008
15. BP, Schiehallion - Emulsion problems, Production restrictions API 27 16. Total, Ofon Emulsion problems, API 45
17
2008
18
19
LOWACC
LOw WAter Content Coalescer Polishing unit. Export Oil Quality < 0,5 % Water in Oil
Interstage Heater
21
Motivation:
The process design basis anticipates that stable oil/water emulsions will occur in the production separators. In addition Aromatic Rich Naphtha is present in the oil. This may cause deposits in the presence of emulsion making the emulsion more stable. The design of the process system has to take no separation in the MP separator into account. Therefore installation of the VIEC in the LP separator is required as a minimum to meet the design basis.
90 80 70 60 50 40
30 20 10 0 0 10 20 Time (min) 30 40 50
VIEC batch test for Ofon 30% WC, 60degC, with demulsifier 100
90 80
Separated water (%)
VIEC batch test for Ofon 30% WC, 60degC, with demulsifier and acid
100 90 80
70 60 50 40 30 20 10 0 0 5 10 15 20
70 60 50 40 30 20 10 0 0 5
VIEC OFF, w/demulsifier and acid VIEC ON, w/demulsifier and acid
Time (min)
10 Time (min)
15
20
25
Result/Status:
VIEC improves the separation significantly for all conditions tested At 60 degC and no chemicals, VIEC increase the free water knock out by a factor of ten, from 7% to 70% after 5 min.
2008 22
23
Technology status
Pilot Technology, Installed in StatoilHydros test loop in Porgrunn (Norway) Ready for field piloting in 2009
Competitive position
Unique technology, but competes with alternative solutions:
Conventional electrostatic coalescers
Marked potential
Any installation new or retrofit where there are space or weight limitations
24
Conductivity profile
Electronics
Signal/Conductivity
Crude Oil
Easiest to detect
Water
25
Technology status
Allready Piloted technology, installed subsea on Troll C Will be Installed medio 2009 on Teekay Petrojarls FPSO for Petrobras Siri project for oil with API grade 12
Competitive position
competes with alternative solutions:
Nucleonic density profilers Condictive level profilers Radar/ultrasound
Marked potential
Cheap and robust none nucleonic level (Oil Water) interface All separators with oil/water interface control
26
HECS
9m x 16 m (144 m2) 280 ton 30 ton 126 ton 0 2
Additional advantages
Cleaner oil Cleaner produced water Les chemical consumption Less heating Smaller supports on deck
27
Cable
BFOU cable 1.5 mm2 twisted pairs, individually screened Fire and flame retardant, halogen-free, <90 oC, <250 V Cables up to 70 meter has been qualified
Electronics
2009
All electronics in cabinet in safe area Communication over TCP/IP (analog output)
28
Gas technology:
Flare Gas Recovery Flare Gas Ignition HC Blanketing VOC Recovery LP Gas Compression
Technology status
Conceptual technology based on patented products. Depends on successful Lowacc piloting
Competitive position
Unique IP protected compact separation Highly competitive where size, weight and transportability are important issues
Marked potential All process module installations where size and weight are important
Portable units Retrofit units
30
32
33
34
2008