Browse Basin CO2 Storage Project
As part of the National CO2 Infrastructure Plan, the Browse Basin CO2 Storage Project is acquiring, interpreting and integrating new and existing pre-competitive data to assess the prospectivity of the Browse Basin for the geological storage of CO2. Attracting and influencing successful resource exploration is also a high priority for the Browse project. Undertaking pre-competitive research and data acquisition has proved a successful approach to achieving this goal.
The Browse Basin is a northeast-trending depocentre situated entirely offshore in the northeast Indian Ocean on Australia's North West Shelf (Figure 1). It covers an area of approximately 140 000km2 and contains in excess of 15km of Paleozoic, Mesozoic and Cenozoic sediments. The Browse Basin is a proven hydrocarbon province with several large gas fields planned for Liquefied Natural Gas (LNG) and condensate development.
Gas accumulations in the Browse Basin are naturally high in CO2 with approximately 7 to 16% CO2 encountered in the Icthys, Calliance and Torosa fields. Initial assessment undertaken by the Carbon Storage Taskforce (CST) indicated that the Browse Basin has significant potential with the capacity to store more than 7GT of CO2 (Carbon Storage Taskforce 2009). The Carbon Storage Taskforce assessment has shown that a detailed study of this basin is required to underpin any future Greenhouse Gas acreage release in this area. This study is beingl undertaken by Geoscience Australia during 2012-15 as part of an integrated study into the resource potential of the basin.
The initial phase of the project identified the CO2 storage related issues in the basin and developed a plan for data acquisition that helped to address these issues. The second phase involves acquiring and processing the data identified in Phase 1, including geological, geophysical and marine environmental data. The third phase of the project will focus on integrating existing and newly acquired data into a full multidisciplinary assessment of the basin for geological storage of CO2 and hydrocarbon prospectivity.
The project is expected to deliver the following outputs:
- Regional distribution of CO2 storage potential and seal integrity
- New geological, geophysical and marine environmental data underpinning the assessments of CO2 storage potential
- Geological interpretation of all available datasets resulting in defining reservoir/seal geometries and their geological and geophysical properties
- Papers, reports, maps and models to present the datasets and results of the assessments.
Achievements to date
Browse Basin 2013 Marine Survey (GA0340/SOL5754)
The marine survey, conducted in collaboration with the Australian Institute of Marine Science (AIMS), was completed in May 2013. This survey targeted several areas on the Leveque Shelf (Figure 1) where previous work has identified a potential long-migration dissolution CO2 storage reservoir (Chirinos et. al., 2008). The survey aimed to investigate possible links between geological formations suitable for CO2 storage, and the shallow geology and seafloor. Data acquired includes: 1070 square kilometres of multibeam and single beam echosounder data in water depths between 40 and 120 metres, 730 line kilometres of multichannel sub-bottom profiler data (sparker source) and 1547 line kilometres of parametric sub-bottom profiler data. Seabed features were examined using 44 line kilometres of sidescan sonar data and physically and visually inspected using a variety of instrumentation at 58 sites.
Initial data analysis has been undertaken and a post-survey report detailing survey location, methodologies and initial findings will be available by the end of March 2014.
Browse Basin 2014 Marine Survey
Planning for an additional marine survey in the Caswell Sub-basin is underway. This survey, likely to take place in late 2014, has similar aims to those of the 2013 survey.
Browse Basin Airborne Magnetic Survey
Data acquisition for a regional aeromagnetic survey over much of the Browse Basin was completed in November 2013. The survey acquired more than 184 000 line kilometres of data in an area of 123 000km2 (Figure 2). The data were measured at a height of 80 metres above sea level on north-south lines separated by 800 metres. The processed data, available for download from the Geophysical Archive Data Delivery System, will be used to aid the mapping of faults and volcanic rocks that could influence the suitably of particular areas for CO2 storage.
Chirinos, A., Morgan, G., Patchett, A. and Lahtinen, A., 2008. Site Characterisation Analysis for Potential CO2 Storage in the Browse Basin, North West Shelf, Australia. Cooperative Research Centre for Greenhouse Gas Technologies, Canberra, Australia, CO2CRC Publication Number RPT08-1014, 139pp.