An Integrated Study of the CO2 Storage Potential in the Offshore Vlaming Sub-Basin: Results of the study undertaken as part of the NCIP program

As part of the National CO2 Infrastructure Plan (NCIP) between 2011 and 2014 Geoscience Australia undertook a comprehensive study in the offshore Vlaming Sub-basin to provide new pre-competitive data and information to underpin potential CO2 storage solutions.
The Vlaming Sub-basin is a Mesozoic depocentre within the southern Perth Basin located about 30 km west of Perth. It covers an area of approximately 23,000 km2 and contains up to 14 km of sediments. The basin lies close to industrial sources of CO2 emissions in the Perth area and contains a number of reservoir-seal pairs potentially suitable for CO2 storage. The Gage Sandstone and the overlying South Perth Shale (SPS) deposited as part of the early post-rift succession are considered the most prospective reservoir-seal pair. Previous assessments of this basin indicated that up 1 GT of CO2 can be stored in the Gage Sandstone reservoir. However, lack of interest in the 2009 Greenhouse Gas acreage release in the Vlaming Sub-basin showed that a more detailed assessment is required.
This study addresses critical scientific issues underpinning CO2 storage potential of the Vlaming Sub-basin that were not sufficiently explored previously. These include:
- better characterisation of the reservoir heterogeneity;
- detailed understanding of the seal quality and integrity;
- a more accurate estimate of the practical storage capacity and,
- an accurate environmental baseline and potential issues of environmental concern
Overall the study confirmed suitability of the Gage Sandstone reservoir for long-term storage of CO2 and provided a more accurate delineation of the suitable storage sites. At the same time it highlighted the importance of careful consideration of the containment and potential environmental impact in any future CO2 storage projects.

2011年至2014年间，作为国家二氧化碳基础设施计划（National CO2 Infrastructure Plan, NCIP）的一部分，澳大利亚地球科学局在近海弗拉明次盆地开展了一项综合研究，旨在提供全新的预竞争性数据与信息，为潜在的二氧化碳封存解决方案提供支撑。
弗拉明次盆地是位于珀斯以西约30公里处的南珀斯盆地内的中生代沉积中心，总面积约23000平方公里，沉积层厚度可达14公里。该盆地毗邻珀斯地区的工业二氧化碳排放源，发育多套潜在适宜二氧化碳封存的储盖组合。其中，作为早期裂谷后沉积序列一部分沉积的盖奇砂岩（Gage Sandstone）及其上覆的南珀斯页岩（South Perth Shale, SPS）被认为是最具潜力的储盖组合。此前对该盆地的评估显示，盖奇砂岩储层可封存多达10亿吨二氧化碳。然而，2009年弗拉明次盆地温室气体区块出让活动未获得市场关注，表明亟需开展更为细致的评估工作。
本研究针对此前未得到充分勘探的、制约弗拉明次盆地二氧化碳封存潜力的关键科学问题展开攻关，具体包括：
- 优化储层非均质性表征；
- 深入解析盖层质量与完整性；
- 更为精准地估算实际封存容量；
- 建立精准的环境基线并排查潜在环境风险问题
总体而言，本研究证实了盖奇砂岩储层用于二氧化碳长期封存的可行性，并更为精准地圈定了适宜的封存场址。同时，研究强调，在未来所有二氧化碳封存项目中，都需审慎考量封存体密封性与潜在环境影响的重要性。