NOPSEMA has granted Santos’ plans to conduct a geotechnical and geophysical survey within Permit WA-437-P in Western Australia, approximately 145km from the town of Port Hedland.
The site survey is required to support pre-engineering studies for any future development and aims to aid in the understanding of the local geology and identify any potential subsea hazards.
The geophysical component of the survey is required to obtain detailed bathymetry measurements and detect hazards on or below the seabed that may exist. Geophysical data collection will consist of single beam echo sounder (SBES); multi beam echo sounder (MBES); side scan sonar (SSS); and sub-bottom profiling (SBP).
The geotechnical survey is required to collect detailed information on the properties of the seabed and the underlying shallow sediments to build a picture of the local geology of the area and support geophysical data collected. The geophysical survey will consist of; in-situ penetration testing; borehole sampling via piston coring, vibrocoring or rock coring (substrate pending); and box coring.
An Operational Area has been defined within Permit WA-437-P, which represents a 10 km x 10 km area encapsulating all potential geotechnical and geophysical survey locations. Water depths across the Operational Area range in water depths from approximately 86–94 m (LAT).
The Survey has been planned as follows:
• Phase 1 to commence as early as Q2 2020 and is estimated to take 15 days to complete.
• Phase 2 may follow Phase 1 or commence as part of a subsequent mobilisation during 2020/2021 and is estimated to take 45 days to complete.
• Both phases will be completed by December 2021.
The timing of the Survey is dependent upon vessel availability, weather conditions and the receipt of the required statutory approvals. Note the stipulated durations do not however, provide for vessel transit times, potential delays caused by ocean conditions, weather downtime, standby and equipment failure or other delays relative to the survey plan, as these factors are difficult to predict or quantify.
Survey activities will be undertaken 24 hours per day.