Advances in Micromodeling using Resistivity Borehole Images

Resistivity borehole images offer a high resolution source of data that is valuable for reservoir characterization. Currently, available imaging tools offer high quality measurements with low susceptibility to borehole conditions or artifacts. There is a high correlation between the image measurements and larger scale resistivity logs such as deep induction or laterologs. In formations such as the McMurray Formation in Alberta, there is also a strong correlation between resistivity and volume of shale. Borehole images are used to obtain high resolution estimates of fluid saturation, porosity and volume of shale. Coarser scale petrophysical logs provide information to solve the inversion problem along with a shaly-sand conductivity approximation such as the Simandoux equation or Waxman-Smits model. Resulting high resolution properties can be used to construct micromodels of the reservoir for extracting effective permeability at arbitrary scales.