SIMULATION OF THE NEUTRON-GAMMA AND GAMMA-GAMMA SIROLOG TOOLS RESPONSE FOR COAL LOGGING USING THE MOCA MONTE-CARLO CODE

The MOCA Monte Carlo code developed at the Bureau de Recherches Geolog iques et Minieres was used to simulate the behaviour of two n-gamma an d gamma-gamma borehole logging tools for coal logging. The tools were developed at the Commonwealth Scientific and Industrial Research Organ ization and are used in the coal mining industry to delineate the coal seams in boreholes and to determine their ash content. The calculatio ns demonstrate the importance of spectrometric measurements in gamma-g amma logging.