DIRECTIONAL DRILLING TECHNIQUES FOR EXPLORATION IN-ADVANCE OF MINING

In-seam directionally drilled horizontal boreholes have prOVided effective solutions in underground coal mines for methane and water drainage and inherently provide an excellent tool for coalbed exploration. Emphasis of the paper will be placed on demonstrating where directionally drilled methane drainage boreholes have identified rapid changes in coalbed elevation, coalbed thickness and faults. Specific directional drilling and coring procedures for exploration in-advance of mining are reviewed. Other directional drilling applications include in-mine horizontal gob ventilation boreholes, identification of abandoned workings, and water drainage boreholes. Applications of the techniques described herein have stimulated considerable interest within the underground coal mining community