Residual oil zones (ROZs) are increasingly gaining interest as potential reservoirs for carbon dioxide (CO₂) storage. Here, we present a national- and regional-scale methodology for estimating prospective CO₂ storage resources in residual oil zones. This methodology uses a volumetric equation that accounts for CO₂ storage as a free phase in pore space and as a dissolved phase in oil and does not assume any oil production associated with CO₂ storage. Reservoir modeling and the CO₂-SCREEN tool are used to demonstrate that CO₂ storage in residual oil zones will predominantly take place in the free phase (approximately 92–97%) with some storage as dissolution in oil (approximately 3–8 %). Based on this preliminary demonstration, the CO₂ storage efficiency for ROZs using this national- and regional-scale method ranges from 0.61 to 7.1 %. This range indicates ROZs have a similar efficiency potential for storing CO₂ as deep saline formations (0.51–5.4 %).

作为潜在的二氧化碳（CO ₂）储藏库，残余油区（ROZ）越来越引起人们的关注。在这里，我们提出了一种国家和地区规模的方法来估算剩余油区中的潜在CO ₂储存资源。该方法使用了体积方程，该方程将CO _2的存储解释为孔隙空间中的自由相和油中的溶解相，并且不假设任何与CO ₂存储相关的产油量。储层建模和CO ₂ -SCREEN工具用于证明CO ₂残留油区中的储存主要发生在自由相中（约92–97％），溶解时在油中的储存量（约3–8％）。基于此初步演示，使用这种国家和地区规模方法进行的ROZ的CO ₂储存效率为0.61％至7.1％。该范围表明ROZ具有与深层盐水形成类似的CO ₂储存潜力（0.51–5.4％）。