BG15 Site Survey Environment Plan
|Activity type||Other survey|
|Submitted by||Lattice Energy Limited|
|Submission date||22 October, 2014|
|Decision date||24 November, 2014|
|Link to previously accepted EP|
Origin Energy Resources Limited (Origin) is proposing to undertake a site survey in the Joseph Bonaparte Gulf (JBG) in 2015 (herein referred to as the BG15 site survey). The survey is being undertaken to provide safety, environmental and insurance planning for a future exploration well that may be drilled with either a jack-up or a semi- submersible drilling rig.
The survey location is proposed to be 4km x 4km square centred on the proposed well location located in exploration permit WA-454-P in the offshore JBG, Western Australia. It is approximately 60 km northeast of the West Australian coast and 345 km to the northeast of the city of Darwin in the Northern Territory.
The survey location will give adequate data coverage for geohazard analysis and will also cover the extent of a semi-submersible drilling rig anchor pattern and potential locations for relief wells. The survey vessel or vessels is yet to be selected. A single specialist all purpose vessel may be utilised for the survey. Alternatively, depending on vessel availability, it may be necessary to undertake the geophysical survey and geotechnical survey with two separate vessels. It is anticipated that the vessel would be between 35-75m in length.
In the event that two vessels are required to undertake the scope of works these vessels will not be operating simultaneously as the geophysical works will be captured prior to a geotechnical vessel being mobilised.
The vessel undertaking geotechnical work may be required to position itself via a mooring system utilising anchors while obtaining bore hole samples.
Depending on weather windows and vessel availability the site survey is scheduled to be undertaken between January and March 2015 for total activity duration of between 5 and 10 days.
The purpose of the survey activity is to obtain geophysical data prior to mobilisation of a drilling rig to location, in particular:
Accurately measure water depths and map seabed topography across the survey areas.
Identify and map the nature and distribution of seabed types within the survey areas.
Characterise and map the thickness, distribution and nature of unconsolidated surficial sediments across the survey areas.
Identify and report on potential seabed obstructions/hazards which could interfere with positioning of semi‐submersible drilling rigs.
Confirm the presence, or lack thereof, of shallow gas prior to the commencement of drilling.
Reduce potential risks/hazards for future proposed drilling at the locations.
In support of the above geophysical survey, to obtain geotechnical soil data for shallow seabed classification and rig emplacement foundation analysis, in particular:
Soil sampling down to 30m below seabed (dependent on rig selection) to ascertain shallow soil properties and types
Cone penetrometers tests (CPT) to ascertain soil strengths and shallow sub seabed foundation study.
Note: This information has been extracted from the EP Summary. Please refer to the attached EP Summary for more information.
|Locations||North West, Northern Territory|
|Commonwealth waters adjacent to||Western Australia|
|Titles (or other instruments)||