Application of the boundary element method to a terrestrial heat flow problem

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In this paper, we apply the boundary element method (BEM) to the 2-D steady state heat flow problem of what would be the perturbation to the regional temperature gradient, and hence heat flow density, determined from temperatures measured in a borehole that passes close to, but does not penetrate, a body of anomalous thermal properties. This type of problem with an infinity boundary is particularly well suited to the BEM.
The results have been compared with those obtained from analytical solutions for bodies of simple shape; it is found that for the worst case of a close approach to a boundary of small radius of curvature, a numerical modelling error of less than 1 per cent can still be obtained provided the length of each element is less than the shortest distance between the calculation point and the object.