Changes

Porosity is the space that exist within rocks or materials, meanwhile pearmebility is the capacity of pore material to let fluida flow.When the porosity increase, the pearmeability will also increase, and the production result will increase.

Porosity is the space that exist within rocks or materials, meanwhile pearmebility is the capacity of pore material to let fluida flow.When the porosity increase, the pearmeability will also increase, and the production result will increase.

[[File:UGM_Vibro_Fig_1.png|thumb|300pxFig 1]]

[[File:UGM_Vibro_Fig_1.png|thumb|300px|{{figure number|1}}Methane Gas endured by the water (Seidled, 2011)]]

===Vibroseismic theory and vibration effect===

===Vibroseismic theory and vibration effect===

Vibration system is medium to save potential energy . this system have capability to save kinetic energy (massa or inertia). Vibration system involve ac-dc transfer energy beetwen potential and kinetic shape. In dimmed system some energy will be wrapped in each vibration cycle and must reaplacement from eksternal source, if the stabil vibration is hold. Although single pysic stucture can save kinetic and potential energy and can remove the energy. In translation move, replacement is distance, rotation as an angle move.<ref>Ralph, B., 1998, Basic Vibration Theory: London.</ref>

Vibration system is medium to save potential energy . this system have capability to save kinetic energy (massa or inertia). Vibration system involve ac-dc transfer energy beetwen potential and kinetic shape. In dimmed system some energy will be wrapped in each vibration cycle and must reaplacement from eksternal source, if the stabil vibration is hold. Although single pysic stucture can save kinetic and potential energy and can remove the energy. In translation move, replacement is distance, rotation as an angle move.<ref name=Ralph>Ralph, B., 1998, Basic Vibration Theory: London.</ref>

[[File:UGM_Vibro_Fig_2.png|thumb|300px|Fig 2]]

[[File:UGM_Vibro_Fig_2.png|thumb|300px|{{figure number|2}}Translation move illustration.<ref name=Ralph />]]

In result of study analysts in laboratorium about core syntesis, vibration stimulation can repair the characteristic of rock physic that increase the porocity (φ) until 15.3% and absolute pearmeability (kabs) until 2.2% and decrease saturated oil remain (Sor) until 53.6%. From the result above need to do the reasearch that analysts the effect of vibration frequencyand pressure about porosity (φ), Kabs and Sor in cornfield.<ref name=Ridaliani_et_al>Ridaliani, O., T. Ariadji, and G. Handayani, 2005, Prediksi Perubahan Sifat Fisik</ref>

In result of study analysts in laboratorium about core syntesis, vibration stimulation can repair the characteristic of rock physic that increase the porocity (φ) until 15.3% and absolute pearmeability (kabs) until 2.2% and decrease saturated oil remain (Sor) until 53.6%. From the result above need to do the reasearch that analysts the effect of vibration frequencyand pressure about porosity (φ), Kabs and Sor in cornfield.<ref name=Ridaliani_et_al>Ridaliani, O., T. Ariadji, and G. Handayani, 2005, Prediksi Perubahan Sifat Fisik</ref>

# Declining production phase, and during the declining production phase, the amount methane produced will decrease until uneconomical stage of production.

# Declining production phase, and during the declining production phase, the amount methane produced will decrease until uneconomical stage of production.

[[File:UGM_Vibro_Fig_3.png|thumb|300 px|Fig 3]]

[[File:UGM_Vibro_Fig_3.png|thumb|300 px|{{figure number|3}}CBM production gas concept, showing dewatering phase, stable production phase, and decline phase(Rogers, 1994).\]

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 />