The Pluto 4D (time lapse) MSS survey commenced late November 2015, and is expected to take approximately 55 days to acquire the survey data.
 
The Pluto 4D MSS will provide an improvement on the current seismic data set, both in terms of delivering a timelapse 4D monitor survey matching the spatial positions of the shots and receivers of the original Pluto 2004 3D vintage dataset, and a higher definition baseline of 3D seismic data for future 4D seismic acquisitions in both the Pluto and Xena fields. The 4D and 3D components of the survey will be undertaken as a single survey, using the same array and source volume, over the same operational area.
 
SURVEY DETAILS
 
The proposed Pluto 4D MSS has a total survey area of about 780 km2, surrounded by a 15 km buffer making up a total Operational Area of approximately 3,710 km2. The Operational Area is within 150 km north-west of Dampier and 25 km north-west from the nearest shoreline, the Montebello Islands.
 
The ‘survey area’ is the vicinity within which the majority of seismic acoustic emissions will occur for the purposes of acquiring data. Additionally, within the ‘Operational Area’ the seismic source may be discharged at or below full capacity (power) for the purpose of run-outs, source testing and soft starts.
 
The proposed Pluto 4D MSS survey area is included within the Operational Area and covers petroleum permits WA-34-L, WA-350-P R1, WA-47-L, WA-46-L, WA-48-L, WA-49-L, WA-21-R, WA-23-R, WA-500-P, W14-14 and W14-20.
 
The proposed Pluto 4D MSS Operational Area covers the additional petroleum permits of WA-1-IL, WA-5-R, WA-427-P, WA-444-P, WA-15-R, WA-356-P and WA-253-P.
 
The Pluto 4D MSS is currently in operation, having commenced on 27 November 2015, is expected to take approximately 55 days to acquire, and is anticipated to be concluded in January 2016 subject to operational constraints and prevailing weather conditions.
 
ACTIVITY SUMMARY
 
Seismic surveying is commonly used in the oil and gas industry to improve understanding of subsurface geology.
For the Pluto 4D MSS, seismic data will be collected using a purpose-built seismic survey vessel towing dual acoustic source arrays and hydrophone cables, also known as streamers.
 
The acoustic emissions from the source arrays will be detected by the hydrophone cables and recorded on board the seismic vessel. The reflected sound is then processed to provide information about the structure and composition of geological formations below the seabed to identify potential hydrocarbon reservoirs.
 
For the Pluto 4D MSS, the source arrays will have a total volume of less than 3150 cubic inches and will be towed at a depth of 6 to 9 m. The vessel will tow up to 12 gel filled hydrophone streamers, which will be up to 7,000 m long, towed at a depth of up to 20 m and the distance between the hydrophone streamers will be approximately 100 m.
 
The seismic vessel will traverse the survey area in a series of pre-determined lines at a speed of approximately 7 to 9 km/h.
 
A support vessel will be present during the survey. Any vessels in the vicinity should keep well clear, particularly when the survey vessel is turning.