Schlumberger Australia Pty Ltd (SLB) is proposing to acquire the Bonaparte Multiclient 3D Marine Seismic Survey (the Seismic Survey) in the Bonaparte Basin to collect high-quality geophysical data regarding rock formations and structures beneath the seabed. The Seismic Survey will be completed before 30 June 2024. It is estimated to take between approximately 120 to 190 days to acquire 12,000 km2, including contingency time for potential vessel or equipment down time and adverse weather conditions. Though the exact survey duration is dependent upon final activity scope.

The Operational Area for the Seismic Survey defines the area where all planned activities within the scope of this Environment Plan (EP) will occur which is located ~200 km north of Port Warrender and Kulumburu, Western Australia, and ~175 km northeast of Ashmore Island and comprises water depths in the order of 20-200 m. The Operational Area is ~26,000 km2, with approximately 50% of the total area constituting water depths >100 m deep.

The Acquisition Area defines the area where the seismic source will be discharged at full power, and extends over ~12,000 km2, with approximately 50%, of the total area constituting depth to seabed of greater than 100 m.

The Seismic Survey will comprise a single Seismic Vessel towing up to twelve seismic streamers with 120 m spacing up to 8 km long, at a speed of approximately 4 – 5 knots (7-9 km/h). The acoustic source will have an effective volume of up to 3,000 in3 and will comprise of two sub-arrays, with thirteen acoustic sources per sub-array (26 in total). During the survey there will be one Support Vessel and one Chase Vessel always accompanying the Seismic Vessel. The role of the Support Vessel and Chase Vessel is to manage any possible interactions between the Seismic Vessel, the seismic array (acoustic source and streamers), and other vessels, receptors or activities occurring in the area.

This EP details the processes involved in assessing the potential risks and impacts to the different receptors within the receiving environment and stakeholders that utilise the area. Included within this assessment are the proposed control measures and operational procedures that will be implemented in order to reduce the potential adverse environmental impacts from the planned operational activities, and risks from unplanned events, to As Low As Reasonably Practicable and to Acceptable Levels. In addition, environmental performance standards have been developed to measure the performance of the control measures and operational procedures that will be implemented throughout the Seismic Survey.

An OPEP along with an OSMP have been developed as part of this EP and are included within it.