Predicting Electrical Anisotropy in the Barents Sea Using Multivariate Statistics

Electrical anisotropy provides key information that can be used to understand regional variations in rock physics properties. Most standard well log suites include only measurements for horizontal resistivity, and vertical resistivity is unknown. The available data from 7220/8–1 (Skrugard) in the Barents Sea, including three-component resistivity measurements were analysed to determine which well logs best characterize the electrical anisotropy in the borehole and determine the relationship between these logs and the vertical resistivity. Using a subset of the data measured at the Skrugard borehole as a training dataset, a nonlinear regression model was found which uses commonly collected well properties to predict vertical resistivity, from which a prediction of electrical anisotropy can be made. Application of the model to the full and offset wells elsewhere in the Barents demonstrates that nonlinear regression modelling provides a good first-order approximation of electrical anisotropy.