Changes

However, the optimum value of frequency will be needed to meet the maximum permeability, there are two ways to determine the optimum value of frequency, there are analytical method and experimental method. To determine the optimum value of frequency analytically, there is formula to count the exact value of optimum frequency, the formula is :

However, the optimum value of frequency will be needed to meet the maximum permeability, there are two ways to determine the optimum value of frequency, there are analytical method and experimental method. To determine the optimum value of frequency analytically, there is formula to count the exact value of optimum frequency, the formula is :

:<math>Equation</math>

:<math>\omega = \frac{Cs}{4H}</math>

where :

where:

ω = optimum frequency (Hz)

* ω = optimum frequency (Hz)

Cs=wavevelocityshear (m/sec)³ .

* Cs=wave velocity shear (m/sec)³ .

H = thick of formation (m)

* H = thick of formation (m)

And for experimental method, the value of optimum frequency is derived from laboratory research. Here is the example of using the experimental method. Given six samples of coal with the code S, A4, L, 3, A6, and I. The vibro seismic method is applied with various frequency’s value in each samples. And the value of permeability is measured using Hasler permeameter tool in each frequency. Tables below show the effect of vibro seismic to the change of permeability and porosity.

And for experimental method, the value of optimum frequency is derived from laboratory research. Here is the example of using the experimental method. Given six samples of coal with the code S, A4, L, 3, A6, and I. The vibro seismic method is applied with various frequency’s value in each samples. And the value of permeability is measured using Hasler permeameter tool in each frequency. Tables below show the effect of vibro seismic to the change of permeability and porosity.