Detection effectiveness of angled versus vertical drilling

Abstract

The paper examines the conventional belief that angled holes are more detection effective than vertical holes with dipping targets. The examination uses a binomial probability framework. Analysis in two and three dimensions shows that all holes can be evaluated for detection effectiveness in three dimensions but only standard vertical holes can be in two dimensions. A programme of standard vertical holes using its two-dimensional advantage had a higher detection capability than one of standard angled holes irrespective of the target's orientation. Although this outcome is at odds with the conventional model, the paper shows that the conventional model contains fundamental flaws. It identifies their source and explains why they occurred. These flaws together with evidence provided by the binomial model lead the paper to conclude that the conventional belief cannot be sustained. The financial implications of this conclusion for the industry are significant.