Development of level-set inversion methodology and software for radio imaging (RIM) data

点击翻译按钮获取中文摘要

The radio imaging method (RIM) is a geophysical technique in which electromagnetic (EM) signals (similar to radio waves, but in the ground) are sent between boreholes. These EM signals are affected by the types of rocks, and whether or not there are zones of mineralization, between the boreholes. Making RIM measurements for many locations of the transmitter in one borehole and many locations of the receiver in the other borehole therefore provides information that could be used to map out any zones of mineralization, and hence ore bodies, between the boreholes. However, current computer modelling and interpretation procedures are based on some significant approximations. These approximations make the computer modelling of a RIM data-set relatively fast. However, these approximations also mean that the modelling and interpretation procedures are limited in how well and how reliably they can map and delineate any ore body. The research proposed here is intended to produce modelling and interpretation methods that do not make use of these approximations but rather take into account the full behaviour of the EM signals in the ground. We will develop the computational mathematics and software for predicting, taking into account the full EM physics of the situation, the RIM data that would be measured for a given hypothesized model of the rock types and mineralization between the boreholes. We will also develop interpretation methodology and software that constructs, from a RIM data-set, a model of the rocks and mineralization between the boreholes, i.e., "inverts" the RIM data. We anticipate that we shall produce an interpretation procedure for RIM data that will be able to provide more accurate and more reliable results than is currently possible. Obtaining a clearer, more reliable picture of the subsurface from RIM data will enable mineral exploration companies to use fewer boreholes to delineate and assess prospective ore bodies. This reduces the cost of finding and developing mineral resources. This in turn helps the health and competitiveness of the mineral exploration industry, which is a significant generator of wealth and provider of employment in Newfoundland and Labrador and in Canada.