Keraudren Extension 3D Marine Seismic Survey

Overview

Santos WA Northwest Pty Ltd (Santos), who are wholly owned by Santos Energy Limited, propose to undertake a 3D seismic marine survey (the ‘survey’) over a portion of exploration permit areas WA-435-P, WA-436-P, WA-437-P and WA-438-P, and surrounding waters in the Bedout Sub-basin in Commonwealth waters off the coast of Western Australia. At its closest point, the survey Operational Area is located approximately 45 kilometres (km) from the nearest land (Bedout Island), 56 km from the nearest mainland coastline and 141 km from the nearest regional town Port Hedland.

The survey data is required to develop regional geologic models to inform the exploration permit retention strategy, and the potential location of future drilling of exploration and development wells.

Seismic acquisition will be via methods and procedures similar to other seismic surveys conducted in Australian waters. The seismic survey vessel will travel along a series of pre-determined lines towing cables (known as streamers or acoustic receivers) which contain microphones (known as hydrophones). As the survey vessel travels along the lines, sound waves will be directed down through the water and into the geology below the seabed. The sound that reflects back is measured by the hydrophones and is later processed to provide information about the structure and composition of geological formations below the seabed.

The survey may be acquired in stages. The exact area to be acquired in each stage will be determined based on operational and timing factors, and in consultation with key stakeholders. To allow for flexibility a period of three years, between 2020 to 2022, is proposed in which to complete the survey. It is Santos’ intention to commence the survey in 2020 and to acquire the full survey within two of the three years.

In order to avoid sensitive fish spawning and whale migration periods, acquisition of the survey will only be undertaken between 1 February to 31 July in any given year. The first phase of acquisition is unlikely to commence before April 2020.

The survey will take at least 132 days to complete, with operations occurring on a 24-hour basis. An additional 30 days of contingency time within the operational area has been provided as part of the environmental assessment.

The survey Operational Area defines the area within which the seismic survey and support vessels will operate and is approximately 20,160 km2. Water depths across the Operational Area range from ~40 m to 250 m.

The Survey Area is comprised of the Ramp-up Zone and Full Power Zone. The Full Power Zone is the area within which the seismic source will be operated in full acquisition mode to achieve the geophysical objectives of the survey. This zone is approximately 8,620 km2, with water depths ranging from 40 m to 168 m. The Ramp-up Zone is a zone that surrounds the full power zone. Typically, this zone will be used to incrementally build the power of the seismic source from non-operation to full capacity, for the purpose of soft starts. This zone is approximately 2,610 km2, with water depths ranging from ~40 m to 185 m.

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 activities. 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 Public comment on environment plans brochure 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 activity, 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 titleholder. 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.