Directional holes provide a wealth of information about bedded deposits. REI uses directional drilling and sidetracking to maintain boreholes in the seam over distances up to 6,000 feet, and by plotting the profile of the borehole from downhole surveys and driller logs, REI provides the mining operation with an indication of seam structure along the full length of the borehole. Sidetracks are developed and intentionally drilled into the roof and floor rock at corresponding drill string lengths to compare elevation data to estimate the seam thickness.
