Upstream Research

Design and Performance Testing of an Integrated, Subsea Compact Separation System for Deep-water Applications

Ed GraveFractionation & Separation Advisor Houston, TX USA

MCE Deepwater DevelopmentApril 8 & 9, 2014Madrid, Spain

Upstream Research

Global Liquids Supply By Type

Oil Sands

NGLs

Deepwater

Tight Oil

BiofuelsOther Liquids

Business IncentivesM

illio

ns o

f oil-

equi

vale

nt b

arre

ls p

er d

ay

2005 Deepwater ~ 3%

2040 Deepwater ~ 12%

Source: 2013 The Outlook for Energy: A View to 2040 (www.exxonmobil.com)

ExxonMobil Resource Base Distribution In Percent Oil-Equivalent Barrels

About 11% of Resources

Source: 2013 Financial & Operation Review(www.exxonmobil.com)

2040 Deepwater Contribution

= ~ 14 MBDOE

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Please refer to disclaimer note regarding forward projections within the referenced sources below:

ExxonMobil Subsea Compact Separation SystemExxonMobil Upstream Research Company (URC) designed and is testing a compact separation system for application in 3000m water depth and internal pressures up to 690 barEM qualification philosophy is to qualify for a wide range instead of specific field conditions to reduce timeline of applicationRobust, flexible to inlet fluids, and scalable

API Gravity:  19˚‐38˚Oil Rate: 60 kBPD/trainGas Rate: 1250 – 4000 Sm3/dayWater Cut: 0‐90%Slug Size: 5m3

Currently being qualified at ProlabNL(3) Crudes with API 19˚, 28˚ & 38˚Scaled to 10‐15 kBPDMethane Gas at 45 barsGas Rate: 33‐497 Am3/hrWater cuts 10‐70%Slug Tests: 0.2 to 0.6m3 Upstream Research

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Simplified Schematic of ExxonMobil Subsea Compact Separation System

being tested at ProLabNL.

ExxonMobil Subsea Compact Separation System

OilURC Inlet Gas/Liquid Slug‐Catcher

URC Liquid/Liquid Pipe Separator and Level Controls

Inlet

Gas

Water

ASCOM Inline De‐sander

ASCOM Hiper™ MixedFlow 2‐stage de‐oiling Hydrocyclones and Canty Oil/Water Monitors

Cyclonic Inline Gas Polisher

Reject

Fast‐Acting MokveldSubsea Control Valve

Liquid Slug Generator

FMC‐CDS IEC tested at FMC separately

Aker CEC™

OiWMonitors

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High-Pressure Testing at Steady-State Conditions

ExxonMobil Multitube/Subsea Slug-Catcher

Test Results/Findings:• Minimal liquid carry-over in majority of test points; gas outlet quality improved at lower liquid levels• Liquid outlet quality improved at higher temperature (i.e., lower viscosity in oil phase) and lower oil flow rates• Determined optimum liquid level and control scheme to minimize both liquid carryover and gas carryunder

0.00

0.40

0.80

1.20

0.00 0.05 0.10 0.15 0.20 0.25 0.30

GVF

(%)

Liquid velocity (m/s)

Effect of Water Cut, Temperature, and Liquid Velocity on Gas Carry-under

20% WC at 50C 70% WC at 50C

20% WC at 70C 70% WC at 70C

Tested at high-pressure (45 barg) in ProLabNL’s HP flow loop facility with natural gas, crude & water; test parameters included liquid level, fluid properties, crude type and flow variations (flow rate, GLR, slugging)

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405M70DMLG 405aM70DMLG

Carry‐over (m

3/h)

Level (%)

Effect of Liquid Level on Liquid Carry-over

Level Carry‐over (coriolis) Carry‐over (calculated)

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200

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Leve

l (m

m)

GVF

(%)

Time (hh:mm)

Effect of Liquid Level on Gas Carry-under

GVF Slug Catcher Level Slug CatcherAdditional CFD analysis performed prior to tests at ProLabNL

5 All data generated by or on behalf of ExxonMobil

High-Pressure Testing at Steady State Conditions

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• A compact, in-line cyclonic separation device for liquid removal from gas-dominated streams; rated for 3000 m water depth and high internal pressures

• Applicable for liquid loading between 0-15 vol%

Results/Findings:• Better separation efficiency during high-pressure tests at higher liquid loadings (> 1.7 vol%) and gas rates (>

200 m3/hr)• Gas carry-under from ASCOM Monoline boot observed during high-pressure tests when liquid residence time

was low; degassing in vertical boot is not sufficient

ASCOM Monoline – Gas Polisher

1.00 1.50 2.00 2.50 3.00 3.50

Effic

ienc

y (%

)

LVF (%)

Medium Crude (All Test Runs)

100-150 m3/h 150-200 m3/h 200-250 m3/h 300-350 m3/h

100

All data generated by or on behalf of ExxonMobil

Courtesy of Ascom Advanced Separation Company

Gas Carryunder- High Pressure Testing

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• Gas carry-under from ASCOM Monoline boot observed during high-pressure tests increased overall gas carryunder in the oil and increased emulsion height in the downstream pipe separator.

• Evaluated horizontal boot in low-pressure, model fluid tests; improves degassing at the same liquid residence time; no effect on liquid carry-over

Results/Findings:• Evaluated horizontal boot in low-pressure, model fluid tests; improves degassing at the same liquid residence

time; no effect on liquid carry-over• Horizontal boot requires fast response level instrument due to limited span length.• The horizontal boot design has not yet been tested in the high pressure loop

200

400

600

800

1000

Den

sity

(kg/

m3)

Residence time (sec)

Medium Crude (All Test Runs)

Design Optimization-Low Pressure

ASCOM Monoline – Optimization

Vertical Boot

Horizontal Boot

All data generated by or on behalf of ExxonMobil

Courtesy of Ascom Advanced Separation Company

High-Pressure Testing at Steady-State Conditions

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Results/Findings:• Oil/water qualities highly dependent upon interface level; small changes in interface level lead to significant

changes in Oil in Water (OiW), as emulsion layer is pulled into water outlet• Oil/water qualities improved at higher temperature (i.e., lower viscosity in oil phase, less stable emulsion

layer), low or high water cuts, and lower liquid flow rates

Pipe separator tested at high-pressure (45 barg) in ProLabNL’s HP flow loop facility with natural gas and crude; test parameters included liquid level, fluid properties, and flow variations (flow rate, GLR, slugging)

WIO/OIW Along Pipe Separator LengthCrude with 40%WC at 35˚C

WIO/OIW Along Pipe Separator LengthCrude with 40%WC at 70˚C

Mixing w/ U-bend pipe separator studied for the large scale unit

ExxonMobil Pipe Separator

All data generated by or on behalf of ExxonMobil

Pipe Separator High-Pressure Testing at Steady-State Conditions NO Aker CEC™

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Heavy oil separation is challenging in compact separation system• Testing has shown that oil and water quality targets are difficult to meet –

requires reduced flow and/or additional heat or chemicals• Incorporating electrostatic coalescence in compact separation system is

expected to enhance performance. Aker CEC™ testing at ProlabNL on going• Aker CEC™ previously tested at Porsgrunn, Norway for the Hebron

qualification tests (2009) with a conventional separator Demonstrated increased separation efficiencies by factor of 5, reducing

residence times from 60 to 10 minutes Data limited to 10% WC and 80-100˚C

WiO/OiW for 2x velocity in Pipe SeparatorLighter Crude with 20%WC at 70˚C

WiO/OiW for 1x velocity vs Sample Points in Pipe SeparatorHeavier Crude with 20%WC at 70˚C

Aker CEC™ & ExxonMobil Pipe Separator

All data generated by or on behalf of ExxonMobil

ConclusionsThe ExxonMobil Subsea Compact Separation System proved to be very robust for a wide range of operating conditionsAs expected performance decreased significantly with heavy oilSlug Catcher ‐ Small variations in liquid level control in slug catcher affects both liquid carryover and gas carryunder. Gas carryunder increased emulsion in Pipe Separator

Horizontal boot in ASCOM Monoline enhanced degassingPipe Separator ‐ OiW concentration highly dependent on liquid level controlClosed most of the gaps with ExxonMobil Compact Separation System 

ExxonMobil Multitube Slug CatcherASCOM Monoline Gas PolisherASCOM Inline De‐sander

Control system dynamic simulation can not be validated in a closed loop systemOil in Water monitors is still an open gap. Working with a number of vendors.

ExxonMobil Pipe SeparatorASCOM Deoiling SystemTracerco’s Profiler™

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Thank You!! Questions?

Upstream Research

Thank You! Questions?

Ed GraveFractionation & Separation Advisor edward.j.grave@exxonmobil.com1‐713‐289‐4770Houston, TX USA

ProlabNL Simplified Flow Loop Schematic

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ExxonMobil URC Subsea Compact Separation System

Test Unit