The previous study indicate that vibration stimulation can change the coal properties, such as porosity and absolute permeability (kabs). Permeability is the main parameter of CBM reservoir in determining response of reservoir – reservoircoal – seam. The high value of permeability will increase the gas production rate related to the increase of gas desorption process speed.<ref name=Ariadji_et_al /> | The previous study indicate that vibration stimulation can change the coal properties, such as porosity and absolute permeability (kabs). Permeability is the main parameter of CBM reservoir in determining response of reservoir – reservoircoal – seam. The high value of permeability will increase the gas production rate related to the increase of gas desorption process speed.<ref name=Ariadji_et_al /> |