Seabed assessments gather detailed information on the bathymetry, seabed features and shallow geology at potential well locations, as well as between the well locations and existing drilling platforms.

They are carried out to determine suitable seabed locations for drilling operations and installation of infrastructure to connect new production wells to the existing pipeline.

The seabed assessments will take place in Commonwealth waters of the Otway and Bass basins.

The Otway development area is approximately:

• 7km from the Victorian coastline,
• 52km from the King Island coastline, and
• 168km from the Tasmanian coastline.

The Bass development area is approximately:

• 82km from the Victorian coastline,
• 89km from the King Island coastline, and
• 39km from the Tasmanian coastline.

The assessments will cover a 3048km2 activity operational area in the Otway Basin and 2374km2 activity operational area in the Bass Basin. Coordinates of the seabed assessment area are provided in the maps below.

Subject to all required approvals, from early 2024, there will be several activities in offshore Commonwealth waters south of Port Campbell and in Bass Strait in existing production and exploration licenses held by Beach.

Activities will involve different phases including seabed assessments (non-seismic), removing suspended wells, as well as drilling and connecting new wells to existing pipelines.

The seabed surveys are estimated to take on average around 20 days for each required well site location within the Operational Area.

Marine users and other interested parties are notified of any activity to be undertaken by Beach via the Australian Hydrographic Office at least four weeks in advance.

The OGV Project will require Environment Plans to be accepted by the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) before commencement of activities.

Environment Plans must include a description of the existing environment and the proposed activities, an evaluation of the impacts and risks, environmental performance outcomes and controls, implementation strategy, and reporting requirements.

Consultation and feedback with anyone whose functions, interests or activities may be affected by the project activities is an important part of developing Environment Plans.

View NOPSEMA's 'Consultation in the course of preparing an environment plan' here.

The assessments are conducted using geotechnical and geophysical activities.

The geophysical survey is required to obtain detailed bathymetry measurements and detect hazards on or below the seabed.

The geotechnical survey is required to collect detailed information on the properties of the seabed and the underlying shallow sediments to build a picture of the local geology of the area and support geophysical data collected.

This information will be used to determine future drilling and infrastructure opportunities for the OGV Project.

The geotechnical activities will be undertaken by a vessel with specialised equipment to carry out the following activities:

• Either a remotely operated vehicle or unmanned aerial vehicle could be used.
• Obtaining core samples for geological analysis of formations below the seabed, from boreholes up to 150m deep, drilled using seawater or or bentonite.
• Determining soil strength and delineating soil stratigraphy using Piezo Cone Penetration Test (PCPT) to a maximum of 30m depth.
• Collecting core samples to a depth of 4m for geological analysis.
• Collecting small samples of surface sediments from the seafloor.
• Using drop and tow cameras to visually observe the physical and biological environment.

Geophysical activities and equipment include:

• Multibeam echosounder for bathymetry mapping.
• Side-scan sonar for identifying seabed features.
• Magnetometer to detect metallic objects on or below the seabed.
• Sub-bottom profiler to identify shallow formation structures below seafloor.

Beach recognises the environmental, heritage, social and economic value in the areas in which we operate. The environment within the project area is characterised by:

• Water depths will be on average 100m but can range up to 1500m.
• Hard sandy seabed consisting of sparsely scattered clumps of solitary sponges, polychaete worms, cone shells and featherstars.

A variety of marine fauna occur in the project area, including the potential presence of:

• Blue, humpback and fin whales, particularly during the summer months.
• Southern right and minke whales, particularly during the winter months.
• Common dolphin and shark species throughout the year.
• New Zealand and Australian fur seals throughout the year.
• Limited numbers of Loggerhead, green and leatherback turtles throughout the year.

Economic value within the project area include:

• Commercial fishing activity.
• Commercial shipping activity.
• Social and heritage values within the project area include:
• Multiple Use Zone of the Zeehan Australian Marine Park.
• Two shipwrecks: ‘S.S. Selje’ and ‘Albert’.
• West Tasmania Canyons key ecological feature.

At Beach, safety is our number one priority. The marine vessels contracted by Beach will operate in accordance with Australian Maritime Standards, regulated by the Australian Maritime Safety Authority. Notices to Mariners will be issued by the Australian Hydrographic Office requesting that vessels do not approach closer than two nautical miles of the assessment vessel.

The National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA), regulates activities in accordance with the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations (2009) (Environment Regulations) and the Offshore Petroleum and Greenhouse Gas Storage Act 2006 (OPGGS Act). The OGV Project will require Environment Plans to be accepted by NOPSEMA before commencement of activities.

Environment Plans must include a description of the existing environment and the proposed activities, an evaluation of the impacts and risks, environmental performance outcomes and controls, implementation strategy, and reporting requirements. They must also demonstrate that consultations with persons or organisations whose functions, interests and activities may be affected by the activities in the Environment Plan (‘relevant persons’), have been carried out in accordance with the regulations.

For successful gas discoveries that will proceed to development, an Offshore Project Proposal (OPP) will be required and will undergo a public consultation phase. Once an OPP is accepted, further Environment Plans will be required for construction activities and commissioning the new wells. Development of an OPP requires Beach to identify impacts and risks of the activities conducted over the life of the project and to demonstrate to NOPSEMA that the impacts and risks will be managed to acceptable levels. The OPP process involves a completeness assessment by NOPSEMA, followed by a public comment period, before final acceptance of the OPP by NOPSEMA.

When conducting any offshore activity, there is an extremely unlikely risk of release of hydrocarbon from a well during drilling (which is primarily gas) or from marine vessel fuel in the event of an accident.

Beach standard operating procedures include emergency response plans which are included in EPs. Preparing emergency response plans involves modelling of all possible hydrocarbon releases in the local area using a worst-case scenario, assuming no control measures are in place. The modelling calculates the transport, spreading, entrainment and evaporation over time, using data on the prevailing metocean conditions (wind, wave, and climate), the volume released, and the physical and chemical properties of the hydrocarbons.

The modelling determines the full extent of the “Environment that may be affected” known as the EMBA. Environment plans must describe the EMBA and include an assessment of the likelihood and consequences of any hydrocarbon release which must be reduced to ALARP through a range of control measures and include detailed response plans.

An emergency response plan describes the arrangements that must be in place for responding to and monitoring any release of hydrocarbon and include:

• 24/7 on-call team for rapid response clean-up actions including mobilisation of personnel and equipment.
• 24/7 on-call team for modelling and monitoring of a hydrocarbon release to inform response activities, and monitoring of effectiveness of response activities.
• Control measures necessary for ensuring rapid response and maintenance of capabilities (personnel and equipment).

These arrangements are based on the worse case event associated with the proposed activities to ensure that Beach has the appropriate level of response arrangements and capability. Beach maintains a current contract with Australian Marine Oil Spill Centre (AMOSC) based in Geelong for access to spill response resources and personnel. In Victoria, the Department of Transport is the control agency for marine pollution emergencies.

For more information on hydrocarbon release modelling and why it is required for the preparation of environment plans, click here to watch a video on the NOPSEMA website.