Specifies procedures for the determination of the desorbed gas content of coal and carbonaceous material by directly measuring the volume of gas, using the water displacement method, from material obtained by coring or collection of lump samples.
Table of contents
Header
About this publication
Preface
1 Scope
2 Referenced documents
3 Definitions
4 Principle
5 Apparatus
5.1 Canister
5.2 Splits
5.3 Volume measurement apparatus
5.3.1 General
5.3.2 Measurement system
5.3.3 Assembling
5.4 Gas sampling apparatus
5.5 Temperature control of canisters
5.6 Coal crusher
5.7 Weighing device
5.8 Miscellaneous equipment
6 Preparation for field testing
7 Sampling
7.1 General
7.2 Surface bore cores
7.3 Underground bore cores
7.4 Lump sampling
8 Measuring gas quantities—slow desorption method
8.1 Determination of Q1
8.2 Determination of Q2
8.3 Determination of Q3
8.4 Determination of Q3′
9 Measuring gas quantities—fast desorption method
9.1 Procedure
10 Measuring gas composition
11 Calculations
11.1 General
11.2 Calculation of Q1
11.3 Calculation of Q2
11.4 Calculation of Q3
11.5 Calculation of measured gas content Qm
11.6 Calculation of Q3′
11.7 Calculation of Qt
11.8 Measurement of uncertainty
12 Data retention
13 Test report
13.1 General
13.2 Hole and sample identification
13.3 Methodology
13.4 Sampling time
13.5 Sample properties
13.6 Upset conditions
Appendix A
A1 System leakage
A2 Origin of sample
A3 Solubility of carbon dioxide in water
A4 Partial pressure effects on the equilibrium end point for desorption
A5 Desorption rate (effect on lost gas calculation)
A6 Temperature (effect upon magnitude of desorption)
A6.1 Lost gas
A6.2 During slow desorption
A6.3 During crushing
A7 Barometric pressure (effect on the magnitude of desorption)
A8 Borehole back pressure
A9 Sample moisture level (wet or dry)
A10 Accuracy of the measuring apparatus
Appendix B
B1 Scope
B2 Calculation of instantaneous gas volume in the measuring system
B3 Incremental volume of desorbed gas
B4 Example—estimation of instantaneous gas volume
B5 Determination of Q2
B6 Calculation of uncertainty
B7 Example—calculation of uncertainty for instantaneous volume of gas in the system
Appendix C
C1 General
C2 Direct method of measurement of Q3′
C3 Example
Appendix D
D1 Principle
D2 Mathematical basis for determination of lost gas, Q1
