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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


Topics / Outline

Unocal Thailand Operations

Produced Water Treatment Process

Improved OiW Monitor & Installation

Conclusions


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


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


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


Produced Water Treatment

Overboard discharge Overboard discharge limits:limits:

•• 30 ppm TPH30 ppm TPH

•• 10 ppb Hg10 ppb Hg

•• 250 ppb As250 ppb As


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


Produced Water Treatment Process

Skim Tank

Injection Pump

To Wellhead Platformfor Reinjection

DesanderCyclone

Chemical TreatingProcess

Clarified Water to Sea

Chemical additionsSeparator

SludgeSludge

DeoilerCyclone


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


Advanced Sensor Presentation


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.


OIW EX 1000 Oil in Water Analyser


OIW EX 1000 Oil in Water Analyser

InstallationStatoilHydro, Brage


Measurement Technique

Laser induced UV Fluorescence


Online Analyser Challenges

1. Fouling

2. Oil Droplet Size Variation

3. Chemical Additive Interference

4. Operating Range

5. Accessibility


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.



•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.


Ultrasonic Activity Video

The combined Optical-Ultrasonic sensor head provides cleaning and sample homogenisation.



•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


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


Benchamas

Crude Oil + 300ppm Corrosion Inhibitor PX 0191


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



•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


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.


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

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