Deviation of a bore hole during drilling

Multivariate Analysis of Bore Hole Discontinuity Data

This paper describes a new and cost effective method of analyzing hard rock discontinuities from oriented core bore hole data. This algorithm uses multivariate cluster analysis to group discontinuities (joints) into sets based on orientation and spatial position (spacing) along the bore hole, and to display the data in a three dimensional stereonet. Although drift or surface exposure mapping da...

Micro-hole drilling with femtosecond fiber laser

In this paper, micro-hole drilling in ambient air is presented using fs fiber laser (750 fs & 1030 nm). Micro holes were fabricated in both transparent (glasses) and non-transparent materials (metals and tissues). Hole shape and morphology was characterized and evaluated with optical microscope and scanning electron microscopy (SEM). Debris-free micro holes with good roundness and no thermal da...

Statistics and Time Series Analyses of BTA Deep Hole Drilling

BTA 1 deep hole drilling is a method for producing precision bores with high length to diameter ratios. The long and slender tools feature low torsional and bending stiffness. This may lead to undesirable dynamic disturbances of the machining process usually classified as either chatter vibration or spiralling. Prediction and identification of the causes of these process failures is important f...

Spiralling in BTA Deep-hole Drilling: Models of Varying Frequencies

A new method for the determination of geophysical parameters by radon concentration measurements in bore-hole.

We propose a new method to measure the (222)Rn concentration in a closed bore-hole and to use the results for estimation of the diffusion parameter and the average radium content of the surrounding geological formations. In a closed bore-hole, only several meters from the surface, the radon concentration is rather constant (in the +/-15% range) under different meteorological conditions. The inf...