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Seeing Coal Seam Top Ahead of the Drill-bit Through Seismic-While-Drilling

Binzhong ZhouIain MasonStewart Alan GreenhalghShankar Subramaniyan

出版	Deep Exploration Technologies Cooperative Research Centre, 2013
URL	http://books.google.com.hk/books?id=8TWLtQEACAAJ&hl=&source=gbs_api

註釋Blast damage to the tops of coal seams due to incorrect blast stand-off distances is a serious issue, costing the industry about one open cut mine for every 10 operating Australian mines. The current approach for mapping coal seam tops is through drilling and pierce-point logging. To provide appropriate depth control with ±0.2 m accuracy for blast hole drilling, it is, typically, necessary to drill deep reconnaissance boreholes on a 50m x 50m grid well in advance of overburden removal. Pierce-point mapping can be inaccurate and expensive, especially because the seam is often not flat due to rolls and faults. To date, there are no effective and economic techniques to accurately image coal seam structures in the open cut environment where coal seams are shallow (