The author worked as wellsite geologist for a large exploration company during 1977. This report summarises the operational methods employed, and describes a system of encoding borehole data for computer processing. The report may serve as a basis for possible Departmental establishment of a similar data processing system. Exploratory and delineation drilling was carried out on a brown coal deposit which locally was upgraded by thermal metamorphism to a semi-anthracite. Seven coal seams were developed, averaging 50 m in total thickness. Individual seams were laterally extensive and contained numerous tonstein bands and silicified lenses. All coal borehole data were compiled and filed using the COGEO computer system. Personnel were based at a well-appointed field camp including offices and coreshed located within the lease holdings.