Forecasting porosity in depths below well bottom from electromagnetic and electrical logging data
A feasibility study is carried out aimed at the porosity forecast in the depths below the borehole bottom based on the electrical well logging data and results of the magnetotelluric sounding in the Soultz-sous-Foretz area (France). It is shown that application of the neural network approach enables forecasting using the electrical logging data or resistivity determined from the electromagnetic sounding provided in the vicinity of the borehole. If the forecast depth exceeds the borehole length less than twice, the forecast based on the well logging data is more preferable; if this ratio is 5-10 then the forecast based on the inverted electromagnetic sounding data is superior; and in the intermediate range both options are more or less equal.