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Gravis Multi Client 3D Marine Seismic Survey

Activity type Seismic survey
Activity subtypes
Submitted by CGG Services (Australia) Pty Ltd
Submission date 14 April, 2015
Subtype New
Decision date 25 August, 2015
RMS ID 3137
Status Finalised
Outcome Accepted
Link to previously accepted EP

Mr Mark Stanley
Level 1
1 Ord Street
+61 8 9214 6203

Location map (click to enlarge)
Location map - Activity: Gravis Multi Client 3D Marine Seismic Survey (refer to description)

Activity Description and Location
CGG proposes to conduct multi-client three-dimensional (MC3D) marine seismic surveys within the Browse and Bonaparte Basins offshore from Western Australia (WA). The Gravis MC3D MSS polygon is located ~132 km from the mainland coastline of the west Kimberley coastline (Cape Voltaire), and ~44 km southeast of Ashmore Reef Commonwealth Marine Reserve. Browse Island is located ~63 km to the southwest of the polygon. Water depths across the polygon are ~25 to 525.
CGG proposes to conduct individual surveys within the Gravis MC3D MSS using a purpose-built seismic survey vessel. A support vessel will accompany the survey vessel. The survey vessel may be refuelled at sea either within or immediately adjacent to the survey area. At sea refuelling will only take place during daylight hours and will not take place within a distance of 25 km from any emergent land or shallow water features. 
Operational Details
The Gravis MC3D MSS is a typical 3D survey similar to most others conducted in Australian marine waters (in terms of technical methods and procedures). No unique or unusual equipment or operations are proposed.
During the proposed activities, the survey vessel will traverse a series of pre-determined sail lines within the survey area at a speed of ~8-9 km/hr. The operating pressure for the airgun array will be ~ 2,000 psi with a maximum volume of ~4,433 cui and will produce at source sound pulses in the order of 242 dB re 1 µPa-m, at frequencies up to~200 Hz.
CGG plans to commence the Gravis MC3D MSS no earlier than Q2 2015. Although the Gravis MC3D MSS is expected to have an actual acquisition period of no more than 12 months, the individual surveys may be conducted in phases over a period of two (2) years.

Other Details
Locations North West
Commonwealth waters adjacent to Western Australia
Titles (or other instruments) SPA Application 066D20
Current Documents (Finalised)
EP Document

Location map