Abstract:
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´107 m3. 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´107 m3.
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.
