North-west Australia 4D MSS
|Activity type||Seismic survey|
|Submitted by||Woodside Energy Ltd|
|Submission date||13 June, 2019|
|Decision date||10 December, 2019|
|Link to previously accepted EP|
Woodside is planning to conduct a series of marine seismic surveys in three separate geographical areas of Commonwealth waters in North-west Australia, Area A: Pluto/Brunello (Harmony 4D M1); Area B: Scarborough; and Area C: Vincent/Laverda/Cimatti.
The first survey (Pluto 4D M2) is planned to commence in late December 2019 (Q4), notionally followed by Harmony 4D M1 (Brunello field), Scarborough 4D B1, Laverda 4D M1, Cimatti 4D M1 and Vincent 4D M2 The planned duration of each survey is:
Pluto 4D M2 (Area A) – 30 days
Harmony 4D M1 (Area A) – 28 days
Laverda 4D M1 (Area C) – 27 days
Cimatti 4D M1 (Area C) – 10 days
Vincent 4D M2 (Area C) – 9 days
Scarborough 4D B1 (Area B) – 45 days.
It is anticipated that acquisition will start in late December 2019 (Quarter 4) or early 2020 (Quarter 1) and be concluded in Areas A and C by May 2020 and Area B by July 2020. This is subject to the EP acceptance timeline, vessel availability, operational constraints and prevailing weather conditions. Hence, the overall campaign is expected to have a duration of six to seven months.
Area A, which encompasses the Operational Areas for the Pluto 4D M2 and Harmony 4D M1 (Brunello field) surveys, is located in the North Carnarvon Basin, Exmouth Plateau, approximately: 28 km north-west of the Montebello Islands; 17 km west of Rankin Bank; 148 km north-west of Dampier; and 150 km north-northeast of the Ningaloo Coast World Heritage Area (WHA). The south-east portion of Area A extends into the Montebello Marine Park Multiple Use Zone.
Area B, which encompasses the Operational Area for the Scarborough 4D B1 survey, is located in the North Carnarvon Basin, approximately: 217 km west-northwest of the Montebello Islands and Barrow Island; 204 km north-west of North West Cape; 248 km north-west of Onslow; and 185 km north-northeast of the Ningaloo Coast WHA. The southern corner of Area B is located about 50 km from the boundary of the Gascoyne Marine Park.
Area C, which encompasses the Operational Areas for the Laverda 4D M1, Cimatti 4D M1 and Vincent 4D M2 surveys, is located in the North Carnarvon Basin, Exmouth Sub-basin, approximately: 110 km west-southwest of Barrow Island; 17 km north-west of North West Cape; 90 km west-northwest of Onslow; and 2 km from the boundary of the Ningaloo Coast WHA. Part of the south-east boundary of Area C is 2 km from the boundary of the Recreational Use Zone of the Ningaloo Marine Park and the south-western portion of Area C extends into the Gascoyne Marine Park Multiple Use Zone.
All of the proposed seismic surveys are over areas where Woodside has previously acquired seismic data and are termed ‘time lapse’ or 4D surveys. During the proposed activities, the seismic vessel will traverse a series of pre-determined sail lines within each survey Acquisition Area at a speed of approximately 7-9 km/hr.
Acquisition Areas for each survey (i.e. the area within which seismic acoustic emissions will occur for the purposes of acquiring data). Source testing (i.e. bubble tests) will occur within the Acquisition Areas for each survey. Operational Areas for each survey, including the Acquisition Area and a buffer (approximately 15 km wide) surrounding each Acquisition Area for the purpose of line turns, run-ins, run-outs and soft starts. For Area C, the Operational Areas for Laverda and Cimatti have been reduced to allow for a 2 km buffer between each survey Operational Area and the Ningaloo Coast WHA. The seismic source may be discharged at or below full capacity (power) within an approximately 4 km buffer extension to each Acquisition Area along the axes of the planned line turns for the purpose of run-ins, run-outs and soft starts. The seismic source will not be discharged within the Operational Area outside this approximate 4 km buffer. The remaining approximately 11 km of the Operational Area is required for conducting line turns. The seismic source will not be discharged during line turns.