East Coast Supply Project: Offshore Project Proposal

Overview

Cooper Energy is the operator of the Casino Henry Netherby (CHN) development, located in the Otway Basin, off Victoria’s southwest coast in the Bass Strait. The CHN fields were developed incrementally since 2004, with gas transported from the offshore fields, via pipeline, for onshore processing. All gas supplies the domestic market in south-east Australia.

The East Coast Supply Project (East Coast Project) aims to continue to meet the domestic demand for gas as existing CHN fields decline, by continuing to incrementally tie in nearby gas fields into existing CHN infrastructure. Hydrocarbons from these fields would be transported to shore via the existing CHN pipeline and processed at the existing Athena Gas Plant situated about 6 km inland from Port Campbell.

The East Coast Project proposal is within offshore Commonwealth waters of the Otway Basin in water depths between ~50-90 m and is within existing offshore petroleum permits VIC/L24, VIC/L30, VIC/L33, VIC/P44 and VIC/P76.

The East Coast Project comprises up to 8 gas field tie-in opportunities with up to 15 wells, infield flowlines and manifolds. These opportunities include:

• confirmed resources at Annie and Henry fields
• prospective resources at Elanora, Heera, Juliet, Nestor, Isabella, Pecten East.

Cooper Energy has assessed the potential environmental impacts and risks across all phases of the East Coast Project. Phases and associated activities assessed within the scope of the OPP include:

• site surveys – geophysical and geotechnical surveys of the proposed locations
• well construction activities – drilling operations and well testing
• installation and commissioning – installation of subsea infrastructure and testing/start-up evaluations
• operations – hydrocarbon extraction and processing and maintenance, inspection and repair of infrastructure
• decommissioning – well decommissioning and removal of subsea infrastructure
• support operations – MODU, vessels, helicopters, remotely operated vehicles (ROVs).

Activities specifically excluded from the scope of this OPP are:

• exploration drilling
• management and maintenance of existing CHN facilities
• management of onshore activities including the Athena Gas Plant and MLV station
• vessels transiting to or from the operational area.

Offshore campaigns to tie in each of the East Coast Project Fields would not occur all together, nor one directly after another. Though the exact order of field tie-ins is subject to further planning, we propose the tiebacks of individual fields would be staged, consistent with how the existing CHN fields were developed. This staging will factor in the domestic market need for gas and the associated offshore activities would be subject to secondary approvals under the OPGGS Act. As production from fields ceases and subsea equipment reaches the end of its useful life, it will be decommissioned, with the base case for decommissioning being removal of equipment unless there is a better and accepted alternate end state.

The duration of activities for each field will vary (see project timing). Mobile Offshore Drilling Units (MODU) and industry vessels will be required at certain times during the life of the fields, but much of the time there will be little physical activity offshore other than the production of gas via the subsea equipment, located on the seabed well below the sea surface. This subsea equipment will not be visible from shore, or to marine users on the water, as is the case with the existing CHN subsea facilities.

While a MODU and/or vessels are operating offshore, they will require temporary safety exclusion zones. These are localised, typically 500m radius. Petroleum Safety Zones may be established over some subsea equipment for the duration of its use; typically limited to 500m radius around subsea wells.

Providing your comment

The public comment process provides an opportunity for community members to have their say on environmental management aspects of proposed oil and gas projects. To make a submission click on the link below.

If your comments contain sensitive information or if you are unable to use this platform for any reason please refer to our Making public comment on offshore project proposals information paper for alternative options to have your say.

Please be aware that information that is irrelevant to NOPSEMA’s decision making criteria cannot be considered, such as statements of fundamental objection to oil and gas prohects, comments that contain personal threats or profanities, SPAM mail, comments made through online social media channels, petitions and comments that pose questions to NOPSEMA and or/the proponent. NOPSEMA takes threats of a personal nature seriously and will consider legal action should the public comment process be misused to make personal threats to any NOPSEMA employee.