Analysis of cross-sectional shapes of borehole

Abstract

The studies are known to indicate the effect of the shape of a bore-hole cross-section on the results of the explosion including elliptical, square, triangular cross-sectional shapes as well as bore-holes with stress raisers applied to their side surfaces. The parameters of the indicated shapes can affect not only the process of crushing by explosion, but also the design of the drilling tool. Therefore, it is necessary to carry out generalization of the parameters of the cross-sectional shapes, and the article proposes criteria for estimating the shapes of the cross-section of a cavity completely filled with an elongated charge of an explosive. The criteria are considered from the point of view of the effectiveness of the explosive impact on the rock and can be used to create and justify the design of the drilling tool. The analysis is made of the geometric shapes of the cross sections of the explosion cavity using examples of biangular, triangular, and quadri-angular shapes. The specific value of the criteria can be determined for the existing designs of the drilling tool. The interrelations of the considered criteria are shown.