Changes

==Results of the methods==

==Results of the methods==

Picture taken in the program minisee (Figure 1) is processed using Img2por_v003 program. From that program, we calculated the porosity:

Picture taken in the program minisee ([[:File:UDip_CBM_Fig_1.png|Figure 1]]) is processed using Img2por_v003 program. From that program, we calculated the porosity:

[[File:UDip_CBM_Fig_6.png|thumb|right|300px|{{figure number|6}}The cross sections of coal using petrography thin slicing and minisee program]]

[[File:UDip_CBM_Fig_6.png|thumb|right|300px|{{figure number|6}}The cross sections of coal using petrography thin slicing and minisee program]]

From [[:File:UDip_CBM_Fig_6.png|Figure 6]], the red one shows pore of coal and the blue one shows matrix of coal. The information that we get from [[:File:UDip_CBM_Fig_6.png|Figure 6]] is the porosity of coal samples with that program is 24.8%. In the other hand, porosity measurement by method of helium porosity meter which is based on ideal gas law obtained the porosity of coal is 24.4%. It means the maximum probability gas contained in coal equal 24.4–24.8%. Porosity of the resulting value is the value of total porosity (absolute porosity and effective porosity). In addition, the amount of porosity is used to determine the amount of fluids (oil and water) and gas. Permeability values obtained from the test is equal to 40.43 mD. Permeability value shows that a flow of 40.43 milli cc, fluid (gas), moves through porous and fracture. The low of permeability indicated that there is another porosity from fracture as secondary porosity. So, based on our experiment we found that the high porosity result and the low permeability result indicate that this coal dominated by absolute porosity.

From [[:File:UDip_CBM_Fig_6.png|Figure 6]], the red one shows pore of coal and the blue one shows matrix of coal. The information that we get from [[:File:UDip_CBM_Fig_6.png|Figure 6]] is the porosity of coal samples with that program is 24.8%. In the other hand, porosity measurement by method of helium porosity meter which is based on ideal gas law obtained the porosity of coal is 24.4%. It means the maximum probability gas contained in coal equal 24.4–24.8%. Porosity of the resulting value is the value of total porosity (absolute porosity and effective porosity). In addition, the amount of porosity is used to determine the amount of fluids (oil and water) and gas. Permeability values obtained from the test is equal to 40.43 mD. Permeability value shows that a flow of 40.43 milli cc, fluid (gas), moves through porous and fracture. The low of permeability indicated that there is another porosity from fracture as secondary porosity. So, based on our experiment we found that the high porosity result and the low permeability result indicate that this coal dominated by absolute porosity.

From the results of the study concluded that the coal samples had a unique porosity characteristic. This can be seen from the value of 24.8% porosity and permeability values of 40.43 mD. A small value of permeability indicates that it comes from the secondary porosity. As we know, the secondary of porosity comes from fracture. Apart from testing the porosity and permeability test, the uniqueness of the coal samples also can be seen from the SEM test with 400 times, 3000 times, 35,000 times, and 70,000 times magnifications. In addition, the uniqueness can also be on figure-2, figure-3, figure-4, and figure-5. To sum up, the characteristics of sample coal shows that it is good as a CBM reservoir.

From the results of the study concluded that the coal samples had a unique porosity characteristic. This can be seen from the value of 24.8% porosity and permeability values of 40.43 mD. A small value of permeability indicates that it comes from the secondary porosity. As we know, the secondary of porosity comes from fracture. Apart from testing the porosity and permeability test, the uniqueness of the coal samples also can be seen from the SEM test with 400 times, 3000 times, 35,000 times, and 70,000 times magnifications. In addition, the uniqueness can also be on [[:File:UDip_CBM_Fig_2.png|Figure 2]], [[:File:UDip_CBM_Fig_3.png|Figure 3]], [[:File:UDip_CBM_Fig_4.png|Figure 4]], and [[:File:UDip_CBM_Fig_5.png|Figure 5]]. To sum up, the characteristics of sample coal shows that it is good as a CBM reservoir.

==References==

==References==

* Nelson, R. A., 2001, Geologic analysis of Naturally fractured reservoirs: Elsevier, 352 p.

* Nelson, R. A., 2001, Geologic analysis of Naturally fractured reservoirs: Elsevier, 352 p.

* Pirson, S. J., 1958, Oil reservoir engineering: New York, McGraw-Hill, 735 p.

* Pirson, S. J., 1958, Oil reservoir engineering: New York, McGraw-Hill, 735 p.

* Ursin, J. and A. B. Zolotukhin, 1997, Introduction to reservoir engineering: Høyskoleforlaget, Norway, Norwegian Academic Press, 407 p.

* Ursin, J., and A. B. Zolotukhin, 1997, Introduction to reservoir engineering: Høyskoleforlaget, Norway, Norwegian Academic Press, 407 p.