Abstract: Concurrent In-Situ Measurement of Permeability, Gas Content and Gas Saturation; #90234 (2015)

Gas content of coals is typically measured using the Direct Method Analysis (DMA) on freshly cut cores. The problem with the DMA technique is that overall results can be greatly influenced by artefacts of the test apparatus and procedures used by core sample type, sample collection methodology, and analysis conditions. Even if all these factors are precisely controlled, the accuracy of in situ gas content values obtained using the DMA technique can still be greatly compromised through large errors in Q1 values, which can only be predicted, not measured. Compounding this inherent error of the technique is the fact that core desorption is a destructive testing method that cannot be completed twice on the same sample. This means it is not possible to assign error bars on core desorption data, or on the major safety implications of decisions made by using them.