Permeability Characteristics of Coal after Supercritical CO2 Adsorption at Different Temperatures

Abstract EN

CO2 storage in coal seams has become one effective method to reduce CO2 emission and help exploit coalbed methane (CBM).

The permeability is a key parameter for CBM extraction.

In deep coal seams (>800 m), CO2 exists in the supercritical state.

In the present work, permeability tests were performed on briquettes before and after supercritical CO2 (SC-CO2) adsorption at various temperatures to investigate the effects of SC-CO2 adsorption on the permeability.

Experimental results show that SC-CO2 adsorption leads to volumetric expansion and permeability augment.

The permeability enhancement decreases continuously at 35°C, while it initially increases and reduces at pressures exceeding 9 or 10 MPa at 45 or 55°C, respectively.

Besides, the permeability enhancement ratio shows a linear increase with the expansion.

The research provides a basis for further research on the enhanced coalbed methane (ECBM) recovery.