Commonwealth Exploration Vessel Based Activity
|Activity type||Other survey|
|Submitted by||Santos WA Northwest Pty Ltd|
|Submission date||15 December, 2020|
|Status||Under assessment (with titleholder)|
|Link to previously accepted EP|
Phone: 08 6218 7100
To support Santos’ offshore petroleum exploration, development and operational programs, Santos is preparing a five-year Vessel Based Activity (VBA) Environment Plan (EP) for a range of survey activities in three separate areas in commonwealth waters on the North West Shelf:
Area A: WA-437-P; WA-438-P; WA-541-P
Area B: WA WA-1-P; WA-209-P; WA-41-L
Area C: WA-33-R; WA-510-P
Data acquired from these surveys will be used for a variety of purposes such as: to determine seabed properties, provide information on seabed morphology, or to generate site survey reports to inform engineering feasibility studies for Santos’ proposed activities in these areas.
VBA will be undertaken using various survey techniques to support future petroleum activities (for example, drilling).
VBA may involve any of the following activities:
Geophysical and hydrographic surveys such as:
Acquisition of multi-beam echo sounding (MBES) and side-scan sonar (SSS) data to define the bathymetry/seafloor morphology (for example, depth, bedform character) and confirm the absence of debris or other anomalous seabed features.
Identification of any hazards that may impact the location of a mobile offshore drilling unit (MODU) or equipment through sub bottom profiling (SBP).
Geotechnical surveys such as seabed sampling/coring for ground-truthing the surficial geophysics and to support MODU spud-can penetration assessments.
Autonomous underwater vehicle (AUV) and ROV surveys with various equipment attached, to provide information about buried objects and the existing environment (water and seabed parameters).
Metrology surveys to take and provide feedback measurements between subsea structures.
Metocean surveys to understand environmental conditions (for example, currents, tidal range).
Environmental surveys to establish baseline conditions or describe the existing environment including sampling for example, water, plankton, fauna.
To support the above activities, the following may also be required:
Materials transfer and handling.
Vessel anchoring activities.
The activities will take place any time within five years from acceptance of EP (2021 to 2026). To take advantage of a vessel hire/mobilisation, an offshore VBA campaign may extend several weeks consisting of multiple individual VBAs at different locations. It is possible that multiple VBAs will also occur at a single site, the duration of an individual VBA may vary between two and 14 consecutive days. The exception is metocean surveys where equipment (as opposed to vessels) may be deployed in the field for several weeks and/or months for collecting baseline data. Unless otherwise stated in this EP, VBA will be performed during all seasons and will include 24-hour operations.
Up to 12 VBA campaigns may be conducted on an annual basis under this EP.
Area A is approximately 9km from Bedout Island and 50km to the Eighty Mile Beach Marine Park, whilst area B is approximately 45km from the Dampier Archipelago and 71km to Dampier on the mainland. Area C overlaps with the Montebello Australian Marine Park and has adjacent boundaries with the Barrow Island Marine Management Area and Marine Park.