Development of a 3d model to study the co2 sequestration Process in deep unmineable coal seams.

This paper presents a numerical model to study the carbon dioxide (CO2) sequestration process in deep coal seams and to investigate the factors that affect this process. A coal seam lying 1000 m below the ground surface was considered for the simulation. One injecting well was first inserted at the middle of the area under consideration and CO2 was injected for a 10 year period. With one injection well, the storage capacity was calculated as 13×10 m. The number of injecting wells was then increased to 4. It was found that the maximum storage capacity was observed at two well conditions (an increment of 130% of the single well condition). However, further increasing the number of wells (up to 4) reduced the storage capacity to 12.5×10 m. According to the model results, it is clear that CO2 storage capacity in deep unmineable coal seams is dependent on the number of injecting wells and their location and porosity, the permeability of the coal seams, coal bed moisture content and temperature.