GWF-1 Development DrillWell

Gary Nettleship Completion Engineer

4th September 2014

DRIMS#9711174

Disclaimer and important notice

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This presentation contains forward looking statements that are subject to risk factors associated with oil and gas businesses. It is believed that the expectations reflected in these statements are reasonable but they may be affected by a variety of variables and changes in underlying assumptions which could cause actual results or trends to differ materially, including but not limited to: price fluctuations, actual demand, currency fluctuations, drilling and production results, reserve estimates, loss of market, industry competition, environmental risks, physical risks, legislative, fiscal and regulatory developments, economic and financial market conditions in various countries and regions, political risks, project delay or advancement, approvals and cost estimates. All references to dollars, cents or $ in this presentation are to Australian currency, unless otherwise stated. References to “Woodside” may be references to Woodside Petroleum Ltd. or its applicable subsidiaries.

Development Changes - NWS

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Previously: Platforms with multi-TCF* reservoirs Goodwyn, North Rankin and Perseus Now: Subsea tiebacks with smaller reservoirs 10’s to 100’s BCF**

Persephone to

NRA

GWF-1 to GWA 5 wells GWF-2

to GWA

Perseus Over

Goodwyn

Echo Yodel

* TCF is Trillion Standard Cubic Feet ** BCF is Billion Standard Cubic Feet

Overview of GWF-1 Subsea tieback to GWA

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Wells Two SMART dual zone Frac Pack wells Three SMART dual zone ESS* wells Subsea & Topsides 16” pipeline with CRA** lining Control umbilical from GWA platform Optical oil detection on GWA * ESS = Expandable Sand Screens ** CRA = Corrosion Resistant Alloy

GDA01

GDA02

Well Design Drivers

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Opportunity / Risk Impact Wells intersect multiple reservoirs

Increase reserves per well by producing multiple zones

Monitor un-produced zones for depletion

Some reservoirs have insufficient reserves to justify a well

Oil production reduces condensate value Shut off oil or water production zone

to produce gas from other zones Driver to use ‘smart’ completion

Water production exceeds production system capacity

High subsea well intervention costs

Transient sand production likely in high rate subsea gas well

Subsea well requires sand control Select conservative sand control method – Gravel pack

Limited core material for sand control selection

Smart* subsea well with multiple zones & sand control *Smart = Real time acquisition of pressure and temperature data and remote control of zonal flow

Greater Western Flank 1 Development

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Five subsea wells tied back to Goodwyn Platform via 16” pipeline Three work phases: 1. Drilled five wells in 2012 2. Complete GDA01 & GDA02 in 2013 3. Complete three Tidepole wells

GDA01 & GDA02: Two zone Frac Pack Two ‘S’ shaped wells Monitoring zone with cable-less gauges SMART completion

GDA01 & GDA02 Completion Schematic

Cure losses Clean up x 2 Perforate Lower Frac Pack Install GP Isolate completion Frac Pack

Cure losses Clean up x 2 Perforate Upper Frac Pack Install GP Isolate completion Frac Pack

Install Upper Completion - 2m depth uncertainty over 3200m - 60 hours control line termination - Ensuring flat pack is not damaged

Perforate WBCU Monitoring Cure losses Zone Install Install sump debris plug packer / gauges

12 planned trips in hole New technology 9-5/8” liner installed Small tubing & washpipe

Small debris intolerant components Frac Pack high KH KH = Permeability * Formation Height

Cable-less Gauge Complicated & high risk

HDFAV

2.94” Isolation

Ball Valve

GDA01 Installed dual zone cased hole Frac Pack completion Experienced challenges related to ‘S’ shaped well increasing torque and drag Successful installation of SMART upper completion Successful execution of lower V3 interval gravel pack Compromised gravel pack of upper V5 interval

GDA01 Outcome

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Models predict high KH can be fractured

Acetic Acid for clean up sub-optimal

V5 interval screened out early at 3ppg*

Insufficient proppant across top sand screen

or

Voids in the proppant pack

Gas production erodes exposed sand screen

* ppg = pounds per gallon

Compromised V5 Gravel pack likely cause:

Frac Pack Application & KH

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0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

0 1000 2000 3000 4000 5000 6000

KH (m

D-f

t)

Permeability (mD)

Frac and Pack Analogues

Total Cameroon Analogue

GDA01 V5 interval looking to extend Frac Pack envelope

GDA02 V2 changed to High Rate Water Pack (HRWP) GDA02 V5 remained as Frac Pack

GDA01 V5

GDA02 V2

GDA02 V5

Permeability (mD)

KH (

mD

-ft)

Learning implemented for GDA02

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GDA02 Changes: Increased pump rate from 20 to 27 barrels per minute Pumped 15% HCl acid to clean up perforations – Injectivity increased Committed to gravel pack integrity ‘restress’ check on both zones V2 zone HRWP due to high KH V5 zone Frac Pack dependent on DataFrac, switch to HRWP if needed

Result: V2 successful execution of HRWP – 14,000 lb proppant placed V5 successful execution of Frac Pack – 39,000 lb proppant placed up to 6 ppg Restress showed proppant above sand screens for both zones

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Learning: Increase Development focus on D&C risk Examples Subsea reducing scope / risk by centralising wells at manifolds resulting in ‘S’ shaped wells Reservoir accessing more reserves with two zones versus single zone Accelerating D&C work to increase overall project value

Risk Balance Between Functions

Central Deviated

Central S-Shape

Single Zone

2-zone SMART

HRWP ESS

Subsea Well Constructability Risk

2-zone SMART

F&P

Distributed Vertical

GDA01

0

5

10 D&C

SS Res

Functional Complexity

(GDA)

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Key Learning:

Increased challenge with other functions to balance project risk

Preference for lower risk well types

Increased Front End Loading for new complex well designs

DEVELOPMENT EXAMPLE Previous concept: Three SMART dual zone CHGP* After concept challenge: One SMART dual zone CHGP Two single zone OHGP** * CHGP = Cased Hole Gravel Pack ** OHGP = Open Hole Gravel Pack

Subsea Well Constructability Risk 3 Wells

1 Well

2 Wells

Implementation for future projects

Central Deviated

Central S-Shape

Distributed Vertical

Single Zone

2-zone SMART

HRWP ESS

2-zone SMART

F&P