Impacts of coal shrinkage, permeability and petrography on gas regime in minees case study:tahmoor coal mine,NSW, Australia

The volumetric changes in the coal matrix (coal shirinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory.the sharinkage and permeability of coal were examined with respect to changing gas type and confining pressures.the shirinkage tests were carried out in high-pressure bombs while the permeablity study was conducted in a specially constructed high-pressure chamber.methane (CH4) , carbon dioxid (CO2), nitrogen, (N2) and a 50%-50% volume mixture of CO2/CH4 gas were used in the study.the tests showed that under different pressure levels gas type affected permeability and shirinkage characteristics of coal.this paper presents a case study of tahmoor colliery,NSW, australia and overall discussion on coal shrinkage, permeability and coal petrography data of tahmoor that permits a better understanding of the gas regime in this mine.the result are important to the further understanding of the inter-relationship between gas flow,the coal matrix .and permeability in normal (and tight conditions( locally referred to as disturbed coal

Keywords:

coal , Methane , Permeability