Ten exploration boreholes were drilled (Ranging from 271m to 446m TD) to identify the depth and thickness of potential coal seams. The majority were open hole with a few being cased. Although most holes were cored, the addition of wireline logging was able to accurately provide the client with data where core recovery was poor or missing altogether where fractures/cavities were present.
To achieve this Robertson Geo deployed the Formation Density probe (The tool of choice for coal logging). The active windows of the source and detectors are maintained in contact with the borehole wall by a motorised caliper arm, its three sodium iodide crystal detectors all of which are able to penetrate steel pipe in cased holes, makes this a versatile probe.
Robertson Geo provided the client with data allowing it to identify accurately the depth and thickness of the coal seams in situ. In addition to this the density values in open holes helped to estimate the grade of the coal present, and the commercial viability of the project. Click for more information