Prediction of Log-Transmissivity

Abstract

Two physically based models are derived that can be used to predict the log-transmissivity from the lithology, e.g. as logged in boreholes. The first model uses the lithology as the only predictor, whereas the second model uses the lithology and the specific capacity as simultaneous predictors. The model parameters can be estimated by statistical methods from actual observations. The methods are applied to three case studies. A comparison with Christensen (1995) shows that the lithology in some cases is a better single predictor of log-transmissivity than the specific capacty; in other cases the opposite is true. This suggests that the proposed joint model is preferable to either of the single predictor models. In two cases the joint model improves the prediction considerably when compared with the single predictor models; in the third case the joint model is at least as good as the single predictor models.