Estimation of parameters for thin-layered formations from high-frequency induction logging data in horizontal boreholes

This paper deals with study of the possibility of estimating the parameters of thin-layered formations from diagrams of high-frequency induction loggi ng in boreholes with horizontal completion. The authors have carried out an alysis of the functions of relative sensitivity to the longitudinal and tra nsverse components of electric resistivity of a bed surrounded with isotrop ic host rocks. It is shown that thin-layered intervals may be distinguished in section from diagrams obtained with short probes, and a spectral analys is of signals can permit determination of the spatial period of interbeds a lternation. By automatic inversion of data obtained with long probes, the p arameters of electric macroanisotropy for thin interbeds can be estimated. A practical implementation of the method for estimating the efficient thick nesses and electric resistivities of terrigenous thin-layered logging is ex emplified.