1 Woodside Consultation Information | WA-28-P Exploration and Appraisal Drilling

Consultation Information SheetMay 2018

Key information+ Woodside is preparing an Environment Plan to undertake drilling activities

within the Exploration Permit WA-28-P.

+ The Environment Plan will encompass potential drilling activities for up to six wells, one of which is confirmed. The remaining five are contingent.

+ The proposed drilling activities are located in water depths ranging 64 m - 129 m in Commonwealth waters, approximately 107 km north-west of Dampier, Western Australia.

+ Drilling activities are scheduled to commence as early as H1 2019.

WA-28-P EXPLORATION AND APPRAISAL DRILLING

CARNARVON BASIN, NORTH-WEST WESTERN AUSTRALIA

2 Woodside Consultation Information | WA-28-P Exploration and Appraisal Drilling

About the consultation

Activity overview

+ Woodside is preparing an Environment Plan (EP) to undertake drilling activities within the Exploration Permit WA-28-P.

+ The permit area is located in Commonwealth waters, approximately 107 km north-west of Dampier offshore Western Australia. The permit covers a total area of 322km2 in water depths ranging from 64 m - 129 m.

+ The EP will cover drilling activities for up to six wells, one of which is confirmed. The remaining five are contingent. Three of the six wells will be exploration wells and the remaining three will be appraisal wells.

+ The confirmed well proposed for drilling within the permit area is the Achernar exploration well.

+ Detailed planning and scheduling of the Achernar exploration well is currently being undertaken. The remaining exploration and appraisal wells will be confirmed and planned pending outcomes of Achernar or as required under Exploration Permit Area requirements issued under the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations 2009 (Cth) (OPGGS Act).

+ When timing of the contingent wells is known and drilling activities confirmed, stakeholder notifications will be undertaken.

+ The proposed drilling activities are scheduled to commence as early as H1 2019.

Activity locationThe proposed drilling activities are located in Exploration Permit WA-28-P, in Commonwealth waters and approximately 107 km north-west of Dampier (Figure 1). The closest landfall to the permit area is the Dampier Archipelago, approximately 85 km south south-east at the closest point.

The permit area is located outside of any established and proposed Commonwealth and State Marine Protected Areas, and outside of established shipping fairways. The activities are planned to be undertaken in an area of low environmental sensitivity with no Critical Habitats or Threatened Ecological Communities, as listed under the Environment Protection and Biodiversity Conservation 1999 (Cth) (EPBC Act), present in the permit area.

A 500 m radius safety exclusion zone will be in place around the drilling locations for the duration of all drilling activities. A 500 m safety zone will also exist around the installation support vessel (ISV) during possible Conductor Anchor Node (CAN) installation.

Approximate location details for the drilling activities are provided in Table 1.

While the mobile offshore drilling unit (MODU) is on location, work will be carried out in the permit 24 hours a day, seven days per week, except where controls developed in the Environment Plan or associated safety case require otherwise.

Activity durationThe proposed drilling activities are scheduled to commence as early as H1 2019. Drilling of the Achernar and other wells (exploration and appraisal) is expected to take approximately 90-120 days per well (including mobilisation, demobilisation and contingency, and excluding well testing activities) to complete. There are no planned concurrent drilling activities in this EP.

Timing and duration of these activities is subject to change due to project schedule requirements, MODU/vessel availability, unforeseen circumstances and weather.

Activity detailsExploration and appraisal wells are used to explore for and confirm new accumulations of oil and gas.

The proposed wells will be drilled in multiple phases.

The first phase is called ‘spudding’, where a hole will be drilled and a conductor casing will be cemented into the ocean floor. For the proposed drilling activities, there is also the option to spud the well by installing a CAN instead of cementing conductor casing into the ocean floor. If this approach is chosen, an ISV will carry out offline installation to deploy the CAN unit prior to drilling commencing. CAN installation has the potential to reduce drill times on wells. The CAN will be retrieved after the completion of drilling activities. Once the cement casing conductor or CAN is installed, a wellhead is secured to the conductor to provide structural integrity in preparation for the upcoming drilling operations.

Next, the well will be drilled down from inside the conductor casing to the desired depth. The well will then be cased and cemented to further strengthen the well and contain formation pressure. This process of drilling and casing continues as required until reaching the target reservoir.

Drilling fluids will be injected into the well while drilling which helps to strengthen the walls of the well and bring rock samples back to the surface for testing.

To prevent water, oil or gas from flowing out of the well, a blow-out preventer (BOP) is installed on top of the wellhead. The BOP is used to control and monitor the well during drilling operations. A marine riser will also be installed to provide a physical connection between the well and the moored semi-submersible MODU.

At the conclusion of drilling activities for each well, the wells will be sealed by injecting cement at various depths to create barriers between the subsurface and seabed.

Following this, the marine riser and BOP will be removed and the wellhead assembly will be cut off below the seabed and retrieved, unless recognised removal techniques are ineffective (management measure as per the Environment Plan).

2 Woodside Consultation Information | WA-28-P Exploration and Appraisal Drilling 3 Woodside Consultation Information | WA-28-P Exploration and Appraisal Drilling

About the operations

Vessels and drill rigDrilling will be undertaken using a MODU. Typically two support vessels will be supporting the MODU for the duration of the drilling activities.

Support vessels will be used to transport equipment and materials between the MODU and Dampier Port. One vessel will be present in the vicinity of the MODU at all times and the other will travel between the MODU and Dampier Port throughout the drilling activities.

The decision to install a CAN, and the assignment of a MODU and support vessels has not been made at the time of publication.

Table 1: Approximate location details for the proposed drilling activities.1

Activity Water Depth (approximate in LAT)

Latitude Longitude Exploration Permit

Achernar exploration well

123 m 190 28’ 04.723” S 1160 18’ 18.177” E

WA-28-P

Permit boundary

Exploration wells 2 and 32

64 m – 129 m

190 24’ 55.224” S

190 44’ 55.232” S

190 44’ 55.235” S

190 24’ 55.227” S

1160 20’ 04.73” E

1160 20’ 04.74” E

1160 15’ 04.741” E

1160 15’ 04.73” E

Appraisal wells 1-32

190 24’ 55.224” S

190 44’ 55.232” S

190 44’ 55.235” S

190 24’ 55.227” S

1160 20’ 04.73” E

1160 20’ 04.74” E

1160 15’ 04.741” E

1160 15’ 04.73” E

Figure 1: Locations of Exploration Permit WA-28-P and the proposed Achernar well.1

1 Location coordinates for the Achernar well are subject to change following joint venture approval.2 Subsequent exploration and appraisal well locations will be within the permit boundary.

4 Woodside Consultation Information | WA-28-P Exploration and Appraisal Drilling

Environmental management

Woodside has a long history of safely and successfully drilling exploration, appraisal and production wells in offshore Western Australia.

Woodside has undertaken an environmental risk assessment for the proposed drilling, considering timing, duration, location and potential environmental impacts arising from drilling activities. As a result, a number of mitigation and management measures will be implemented during the proposed drilling.

Table 2 provides a summary of potential key risks and associated management measures identified for the proposed drilling activities which will be further detailed in the WA-28-P Environment Plan.

Environmental approvalsAn environment plan for the proposed drilling activities will be submitted to the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) for acceptance in accordance with the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulation 2009 (Cth).

Table 2: Summary of potential key risks and associated management measures identified for the WA-28-P exploration and appraisal drilling activities.

Potential Risk and/or Impact Mitigation and/or Management Measure

Vessel collision + Marine notifications will be made to relevant stakeholders, describing the location of the activity and a 500 m radius safety exclusion zone to prevent the risk of vessel collisions.

+ An activity support vessel will be on standby during the drilling activities as required by the MODU Safety Case.

Marine fauna interactions + Measures will be taken to protect marine fauna and ecosystems from vessel activities and to prevent vessel collisions.

Effluent discharge and waste management

+ Routine discharges will meet legal requirements.

+ Other wastes will be transported back to shore for appropriate recycling/disposal.

Hydrocarbon release + Appropriate spill response plans, equipment and materials will be in place and maintained.

+ Appropriate refuelling procedures and equipment will be used to prevent spills to the marine environment.

Safety zones for marine users + A 500 m radius safety zone will be in place around the MODU (and potential ISV) for the duration of the drilling activities.

+ For safety reasons, Woodside requests marine users observe a 4,000 m radius precautionary zone around the MODU/ISV while on location. This is not an exclusion zone as vessels may enter, however extra vigilance is required due to possible presence of moorings, and a higher level of MODU-related activities and vessel traffic.

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Please note that stakeholder feedback will be communicated to NOPSEMA as required under legislation. Woodside will communicate any material changes to the proposed activity to affected stakeholders as they arise.

Providing Feedback

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If you would like to comment on the proposed activities outlined in this fact sheet or would like additional information, please contact Woodside before 14 June 2018.

Lauren Baker-Nicholson Corporate Affairs AdviserWoodside Energy Ltd

E: feedback@woodside.com.au

Toll free: 1800 442 977