Prediction on reservoir parameters and simulation on <scp> CO ₂ </scp> geological sequestration for a deep coal seam

Abstract Deep coal seam is the major reservoir for CO 2 geological sequestration. The sedimentation evaluation simulation on Qin county of China indicates that the reservoir subsidence totally occurs before early Cretaceous, while the uplift mainly focuses after early Cretaceous. For this type of deposition, the porosity, permeability, and gas content are greatly influenced by buried depth. By collecting values for samples with shallow buried depths, the basic simulation parameters containing porosity, permeability, gas content, and others are all predicted. CO 2 is difficult to be injected, and the maximum injection rate is generally lower than 500 m 3 /d caused by the extremely low origin permeability. If the permeability increases to 1 mD, the CO 2 injection capacity is strongly improved, and the geological sequestration time is shortened. The unit CO 2 injection volume is defined in this article, which refers to the CO 2 injection volume per thickness and permeability, which is used to evaluate the CO 2 geological sequestration ability for a target reservoir. Permeability generally decreases within the simulation area, which leads to the drop of CO 2 injection and CBM production after several years. A long‐term, low‐pressure CO 2 injection and a suitable ratio of injection well to production well are all meaningful to achieve a maximum CO 2 injection ability and CBM production.