The Lower Jurassic Precipice Sandstone and Evergreen Formation are an important prospective reservoir–seal pair for CO2 storage in the Surat Basin, Australia. However, there is little seismic and well data to constrain reservoir modelling in the best notional injection area. To test the likely storage performance, three contrasting sector-scale static reservoir models were built to capture the range of geological uncertainty in facies distribution and reservoir properties. These considered sectors of the Surat Basin with different palaeogeographical arrangements. The models were focused on capturing detail at the interface between the top of the Precipice Sandstone (Blocky Sandstone Reservoir: BSR) and the overlying basal portions of the Evergreen Formation (Transition Zone: TZ), a critical area for understanding CO2 injection. Object modelling was used for the BSR and lower TZ. Stochastic modelling was implemented for the upper TZ and the Ultimate Seal because these zones were less sensitive to facies distributions. Porosity was modelled stochastically, and permeability calculated using porosity–permeability transformation functions. Dynamic simulation showed the TZ has the capacity to arrest CO2 flow out of the BSR given appropriate CO2 injection conditions. This study shows a method of capturing uncertainty in geological heterogeneity when data are sparse or absent. The promising initial modelling results of CO2 injection into the Surat Basin suggests that it presents a real option for carbon storage at a climate mitigation scale. Further investigation should focus on assessing other major risks associated with carbon storage such as fault seals, reactive fluid transport and the impact of legacy wells. This article is part of the Energy Geoscience Series available at https://www.lyellcollection.org/cc/energy-geoscience-series

中文翻译：

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澳大利亚苏拉特盆地悬崖砂岩和常绿地层的概念 CO2 储层建模

下侏罗统悬崖砂岩和常绿地层是澳大利亚苏拉特盆地 CO2 封存的重要潜在储层-密封对。然而，几乎没有地震和井数据来约束最佳假想注入区的储层建模。为了测试可能的存储性能，建立了三个对比鲜明的部门规模静态油藏模型，以捕捉相分布和油藏性质的地质不确定性范围。这些被认为是具有不同古地理安排的苏拉特盆地的部分。这些模型的重点是捕捉悬崖砂岩顶部（块状砂岩储层：BSR）和常绿地层（过渡带：TZ）上覆基底部分之间的界面细节，这是了解 CO2 注入的关键区域。对象建模用于 BSR 和较低的 TZ。对上 TZ 和 Ultimate Seal 实施了随机建模，因为这些区域对相分布不太敏感。孔隙度是随机建模的，渗透率使用孔隙度-渗透率转换函数计算。动态模拟显示，在适当的 CO2 注入条件下，TZ 有能力阻止从 BSR 流出的 CO2。本研究展示了一种在数据稀少或缺失时捕捉地质异质性不确定性的方法。向苏拉特盆地注入二氧化碳的初步建模结果表明，它为气候减缓规模的碳储存提供了一个真正的选择。进一步调查应侧重于评估与碳储存相关的其他主要风险，例如断层封闭、反应性流体输送和遗留井的影响。本文是能源地球科学系列的一部分，可在 https://www.lyellcollection.org/cc/energy-geoscience-series