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DOC ID© Chevron 2005
A New, Self-cleaning, Continuous, On-line Oil-in-Water Analyzer for the Petroleum Industry
18th Annual Produced Water Seminar
Darrell L. Gallup, Chevron Energy Technology Co.Khalid Thabeth and Rik Dawson, Advanced Sensors, Ltd.
16 January 2008
Clearlake, TX
DOC ID© Chevron 2005
Topics / Outline
Unocal Thailand Operations
Produced Water Treatment Process
Improved OiW Monitor & Installation
Conclusions
DOC ID© Chevron 2005
Introduction
Gulf of ThailandGulf of Thailand
700 km in length700 km in length600 km in width600 km in widthShallow water:Shallow water:
Average depth Average depth 20 m 20 m (20 (20 –– 100 km 100 km offshore)offshore)Maximum depth Maximum depth 90 m90 m
Chevron FieldsChevron Fields
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Thailand Operations
Exploration and Production:Exploration and Production:
••13 Blocks13 Blocks••5 million acres5 million acres(16,000 sq. (16,000 sq. kilometers)kilometers)••1.5 bcfd natural gas1.5 bcfd natural gas••100,000 bopd 100,000 bopd •• 40,000 bcpd40,000 bcpd
Chevron Oilfields
PTTEP
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Thailand OperationsThailand Operations
Offshore Offshore Facilities:Facilities:
>2500>2500 wells drilledwells drilled
>>114040 platformsplatforms
>1000>1000 kms interfield pipelineskms interfield pipelines
3 FSOs3 FSOs
1 FPSO1 FPSO
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Produced Water Treatment
Overboard discharge Overboard discharge limits:limits:
•• 30 ppm TPH30 ppm TPH
•• 10 ppb Hg10 ppb Hg
•• 250 ppb As250 ppb As
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Thailand OperationsThailand Operations
Water disposal:Water disposal:
••Seven fields currently inject 100% waterSeven fields currently inject 100% water
••By 2009, two additional fields to inject 100% By 2009, two additional fields to inject 100% waterwater
••Two fields currently overboard water at rate Two fields currently overboard water at rate of 10 of 10 –– 30 kbwpd30 kbwpd
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Produced Water Treatment Process
Skim Tank
Injection Pump
To Wellhead Platformfor Reinjection
DesanderCyclone
Chemical TreatingProcess
Clarified Water to Sea
Chemical additionsSeparator
SludgeSludge
DeoilerCyclone
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Produced Water Treatment Process and OiW Monitors
Precipitates from water treatment sometimes fouls conventional OiW monitors. Conventional OiW monitors required constant maintenance, optics cleaning and re-calibration.
Frustrated operators – turn off conventional OiW monitors
Need improved OiW monitor that is less susceptible to fouling by sticky precipitate
Kontavisor OiW Monitor (Systektum) installed in Chevron Netherlands. Difficulty Exporting to Thailand.
Advanced Sensors OiW Monitor
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Advanced Sensor Presentation
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Objective
To produce an accurate, reliable (maintenance free) Oil in Water monitor for effluent discharge, re-injection and process management.
In collaboration with StatoilHydro and Talisman Energy.
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OIW EX 1000 Oil in Water Analyser
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OIW EX 1000 Oil in Water Analyser
InstallationStatoilHydro, Brage
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Measurement Technique
Laser induced UV Fluorescence
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Online Analyser Challenges
1. Fouling
2. Oil Droplet Size Variation
3. Chemical Additive Interference
4. Operating Range
5. Accessibility
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1. Online Analysis Challenges
• Fouling
• Of measurement window
• Chamber
• Pipelines
• Objective: Stay clean. Without the need for manual intervention, use of acids, detergents or introduction of additives.
• Solution:
Combined Ultrasonic transducer and optical sensor.
DOC ID© Chevron 2005
2. Online Analysis Challenges
•Oil Droplet Size Variation
Oil droplet size variation has direct impact to fluorescence measurement
•Objective: Standardisation of oil droplet size. Without the need for manual intervention, or additives.
•Solution: Ultrasonic sample homogenisation.
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Ultrasonic Activity Video
The combined Optical-Ultrasonic sensor head provides cleaning and sample homogenisation.
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3. Online Analysis Challenges
•Chemical Additive Interference
Many process chemicals are now commonly known to fluoresce and corrupt oil in water measurement.
•Objective: Isolate effects of chemical additives from fluorescent measurement.
•Solution: Real Time UV Spectrometer built into unit.
DOC ID© Chevron 2005 Wavelength (nm)
0.00000E+00
2.00000E-06
4.00000E-06
6.00000E-06
8.00000E-06
1.00000E-05
1.20000E-05
1.40000E-05
1.60000E-05
380
391
402
413
424
435
446
457
468
479
490
501
512
523
534
545
556
567
578
589
600
611
622
633
644
655
666
677
688
699
710
721
732
743
754
765
776
AFT Sampling Point (9-8-07)EC1110A (42ppm)EC1188A (0.6ppm)EC1442A (45ppm)EC2176A (9ppm)EC9012A (73ppm)
0.00000E+00
1.00000E-05
2.00000E-05
3.00000E-05
4.00000E-05
5.00000E-05
6.00000E-05W
a
389
399
409
419
429
439
449
459
469
479
489
499
509
519
529
539
549
559
569
579
589
599
609
619
629
639
649
659
669
679
689
699
709
719
729
739
749
759
769
AFT Sampling Point (9-8-07)BHP Surface STBD Slop (90ppm)
UV Spectra results from inbuilt Spectrometer
Crude oil
Produced Water plus chemicals
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Chemicals for testing and respective concentrations: Result2/08/07
Tap Water 0.2ppm (5.0)
EC1110A satellite gas corrosion inhibitor 42 ppm 1.4ppm (14.9) EC2176A Demulsifier 9 ppm 0.8ppm (10.5) MEG Heating medium 181 ppm 0.2ppm (4.5) EC1188A Heating medium Cl 0.60 ppm 0.2ppm (5.0)
EC1442A Export gas corrosion inhibitor 45 ppm 0.4ppm (7.0) EC9021A H2S scavenger 73 ppm 0.2ppm (5.5) EC6354A Coagulant/de-oiler 100 ppm 0.2ppm (5.5) Methanol 5443 ppm 0ppm (1.1)
Test samples are to be prepared with above mentioned concentration.
Measurement after chemical isolation
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Benchamas
Crude Oil + 300ppm Corrosion Inhibitor PX 0191
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Correlation of Instrument vs LabFollowing chemical isolation
Benchamas October 2007
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
2-Oct 3-Oct 4-Oct 6-Oct 7-Oct 8-Oct 10-Oct
11-Oct
12-Oct
14-Oct
15-Oct
17-Oct
18-Oct
19-Oct
21-Oct
22-Oct
24-Oct
25-Oct
27-Oct
29-Oct
30-Oct
PPM
OIW MonitorLab
Number of samples = 63Sample range = 11 – 40ppmAverage variation = 0.5ppm
DOC ID© Chevron 2005
4. Online Analysis Challenges
•Operating Range
0 – 20,000ppm (2% oil concentration)PPM FLU
0 0500 152
1000 1932000 2414000 2896000 3248000 35710000 38112000 40314000 42216000 43118000 44020000 44522000 44824000 44826000 44628000 44630000 44532000 44534000 44436000 44838000 44740000 446
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Online Analyser Challenges
•Remote Accessibility
Field mobilisation generally required for calibration, diagnostics and detailed analysis of water content.
•Objective: Complete remote reach through providing virtual presence.
•Solution: Ethernet and ADSL connectivity.
Live Demonstration available during the week.
DOC ID© Chevron 2005
Conclusions
•EX-100 performs well after 13 months at FPSO
•Excellent agreement with grab samples – SX with Wilks IR
•Operators love “maintenance free” monitor
•EX-1000 performs well after 6 months at FSO
•EX-1000 required on FSO to eliminate interference from demulsifier treatment
•AS OiW monitors reduce lab technician time and solvent use/exposure
•AS OIW monitors alarm to Control Rooms to “early warn” of water system upsets