Jacques R. Tabanou

Fast And Rigorous Inversion of Triaxial Induction Logging Data to Determine Formation Resistivity Anisotropy, Bed Boundary Position, Relative Dip And Azimuth Angles

In this paper, we present a fast and rigorous inversion method to determine formation resistivity anisotropy, formation bed boundary location and relative dip and azimuth angles from a recently developed triaxial induction tool. This tool is fully triaxial and has sets of three orthogonal coils which are located at the same point. The sensitivity matrix with respect to horizontal conductivity, vertical conductivity, formation bed boundary locations is computed rapidly with the help of its analytical expression in a 1D TI anisotropic medium. The relative dip azimuth is solved first by rotating the full tensor measurement. The rest of the parameters are solved simultaneously by using Gauss-Newton minimization. The inversion results on synthetic data and field data show the accuracy and efficiency of the inversion algorithm.

A deep resistivity logging-while-drilling device for proactive geosteering

Reading deep into the formation has always been an ojective of formation evaluation. Historically, when drilling vertical wells, reading deep involved imaging seismic reflectors with intermediate vertical seismic profile (VSP) runs to “look ahead” and to assess invasion or borehole damage with deep-resistivity devices.