gas hydrate - CCOP

Coal Property Analysis
Ten coal samples were analyzed for the properties of heating value, fixed carbon, volatile matter,
moisture, specific gravity, total sulfur, and other mineral matter contents show as shown in Table 2.
Some physical properties were also included such as coal petrography, compressive strength,
and coal permeability and porosity. These properties were correlated directly to the gas
absorption and desorption of the coal.
The volatile matter of the coal was not less than 25% by weight and the coal classification
was sub-bituminous C or higher.
The coal petrography analysis indicated low to moderate gas potential in pore space of the
coal with cleats developing upon drying and release of pressure but with some cleats filled
with minerals.
Compressive and tensile strength tests were modified to the well stimulation artificial coal
seam fracturing. At the approximately 200 meters depth of the Mae Tha coal seam, the
surface compression pressure of 400 psi will be enough to make the fractures and cleats join
in the coal seam.
The measurement results show porosity of 1.85-5.24% with an average of 3.88% and
permeability of 0.034-27.70 md (millidarcies) with an average of 2.5x10 -3 md equivalent to the
long-term pumping test of 2.7 md and equivalent to 1.97x10 -3 meters per day. The result of low
gas flow rate was affected by the low coal bed groundwater yield.
The quality of the coal from the Mae Tha Basin as concluded from the result of the present
analysis is as follows:
Table 2. Result of coal property analysis
Property Maximum Value Minimum Value Mean Value
Fixed carbon (%) 45.47 24.54 36.75
Moisture (%) 21.04 9.32 16.28
Carbon (%) 25.56 15.41 20.66
Hydrogen (%) 4.39 2.96 3.80
Nitrogen (%) 2.16 1.11 1.75
Sulfur (%) 11.16 2.34 3.96
Specified gravity 1.89 1.33 1.49
Heating value (cal/g) 5,683.48 3,147.89 4,666.46
Gas Quantity and Property Analyses
The eleven coal samples and gas samples produced at the well head and collected in canisters
were analyzed for the gas quantity and properties by gas chromatography with the following
results:
The gas in place ranged from 10 to 70 cc/kg and averaged 40 cc/kg or 1.41 cubic feet per ton.
Coal desorption is estimated at average of 35 cc per ton.
New Energy Resources in the CCOP Region - Gas Hydrates and Coalbed Methane 135