ABSTRACT: Reservoir Properties of Banded Coal: Formation and Characterization of Fractures
PATERSON, LINCOLN, CSIRO Division of Geomechanics, Mount Waverley, Victoria, Australia, MICHELLE SMYTH, CSIRO Division of Exploration Geoscience, North Ryde, New South Wales, Australia, KEREK Y. C. CHAN and CHRISTINA SIRAKOFF, Department of Mathematics, Melbourne University, Parkville, Victoria, Australia
We report here on visual observations and numerical simulations of fractures and cleats in coal. This work was motivated by interest in coalbed methane as a resource and the desirability of connected permeable fractures for economic gas recovery. Visual observations with a reflecting microscope have been made after impregnating coal with epoxy resin containing a fluorescent dye. Numerical simulations have been made with a network resistor model that corresponds to a banded elastic medium undergoing shrinkage. Evidence from the microscopic observations and the numerical simulations shows that banding of the coal types has a major role. Bright coals shrink more and are more highly fractured, with the predominant fracture direction being vertical. Bright coals also give higher measured v lues of permeability in the laboratory. This is a step toward estimating coal permeability from petrographic information rather than having to resort to expensive well testing and laboratory core testing.
AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)