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.