Simultaneous Inversion of Galvanic and Induction Logging Measurements to Improve Resolution

Abstract

Improved resolution in estimating fonnation resistivities can provide more accurate values of residual and movable hydrocarbon saturations. Routinely, fonnation resistivity infonnation derived from galvanic and induction logging measurements are interpreted independently. As a result, several models of fonnation resistivity can emerge that are typically not consistent. Here, we illustrate how simultaneous inversion of data from galvanic and induction tools can yield more consistent and better resolved parameters. When measuring fonnation resistivities, differentReferences and illustrations at end of paper 1059 SPE26976 Simultaneous Inversion of Galvanic and Induction Logging Measurements to Improve Resolution 2 complete concept of resolution is proposed that involves earth model, measuring device, data noise, and interpretation technique as components.A number of earth models and tool combinations (Dual Laterolog, Dual Induction, Thin Bed Resistivity Tool, Microlaterolog) are analyzed and discussed under the framework of the proposed resolution concept. The analysis clearly shows the advantages of combining data from different instruments to improve interpreted results.

Multiscale Formation Resistivity Imaging

“…Special multidimensional inversion-based array data interpretation techniques are required to optimize data information extraction. Previously proposed methods for accelerating time-consuming multidimensional inversion processes are usually based on sequential determination of the formation parameters, better initial model determination, or division of the multidimensional inversion process into a sequence of simple one-dimensional processes [1][2][3][4][5] . For example, the rapid inversion method 4-5 performs a sequence of 1D iterations each of which consists of joint log data radial inversions and shoulder-bed corrections at each formation layer.…”