SapuraOMV Upstream (Western Australia) Pty Ltd (SapuraOMV) is titleholder for exploration permit AC/P61 in the Timor Sea and proposes to undertake a relatively small scale 3-dimensional (3D) marine seismic survey over an area encompassing the permit and adjacent areas, referred to as the Gem 3D Marine Seismic Survey.
The survey location lies entirely within Commonwealth waters approximately 250 km offshore of mainland Australia and 650 km from Darwin. Seismic data will be collected within an Acquisition Area which covers approximately 410 km2. The Acquisition Area falls outside (seaward) of the Perth Treaty line amendment to Australia’s Exclusive Economic Zone and hence outside the area where Australian commercial fisheries are permitted to operate. The Acquisition Area is surrounded by a larger Operational Area (~4,760 km2) to allow for line turns, run-ins/run-outs, seismic testing and support activities.
The survey will involve a single, specialist seismic survey vessel towing a seismic source array and ten hydrophone streamers of up to 10 km in length at approximately 9-15 m below the sea surface (water depth dependent). The seismic source will use compressed air to emit regular pulses of sound that reflect off the seabed and underlying geological formations. The hydrophone streamers will be of ‘solid’ (no liquid buoyancy fluids) design and towed with separation distances of approximately 75 m.
While collecting data, the seismic survey vessel will travel at a speed of approximately 4-5 knots, discharging the seismic source (up to 2,820 cubic inches volume) approximately every 12.5 m as it moves along a series of adjacent and parallel lines spaced approximately 375 m apart. The seismic vessel will be accompanied by one or possibly two smaller vessel(s) that will provide operational support, including scouting for potential hazards and helping manage communications with other vessels in the area. Due to the short duration of the survey, there will be no requirement for at sea refueling or crew changes.
The survey is expected to take up to 27 days, inclusive of downtime, and scheduled to occur between January 2020 and Q3 2020 with precise timing subject to receipt of regulatory approvals, weather conditions, vessel availability and other operational considerations.