A preliminary evaluation of carbon dioxide storage capacity in unmineable coalbeds in China

In this study, CO₂ storage capacity in unmineable coalbeds in China at depths of 1,000–2,000 m has been evaluated using the methodology recommended by CSLF. This evaluation is one part of the countrywide CO₂ storage capacity evaluations in China, initiated by the Chinese Ministry of Land and Resources. This level of CO₂ storage capacity evaluation gives a rough scale of assessment with the least site-specific detail. The results show that there is a storage capacity of 98.81 × 10⁸ t CO₂ in coalbeds buried at a depth range of 1,000–2,000 m and 4.26 × 10¹² m³ additional coalbed methane can be recovered by CO₂ injection. These results appear to show great potential and an attractive economic perspective of CO₂ storage in unmineable coalbeds in China. Another part of this study is to classify the potential coalbed basins based on CO₂ storage capacity and storage capacity per unit area. The study results reveal the distribution of the most potential basins for large-scale CO₂ storage and the best economic basins for early CO₂ storage in the future.