Real-time formation anisotropy and dip evaluation using tri-axial induction measurements

摘要

The present disclosure relates to a method to determine a formation property of a subsurface formation. A downhole logging tool having two or more tri-axial antennas is provided and used to obtain azimuthally sensitive data. Borehole correction is performed on the obtained data and a ZD-inversion is performed on the borehole corrected data for all antenna spacing groups. A formation indicator flag is determined and, depending on the determined formation indicator flag, a 1D-axial inversion and/or a 1D-radial inversion is performed over selected zones, or neither is performed. The best ZD-inversion results are selected and the 1D-axial inversion results and/or the 1D-radial inversion results, if any, are combined with the selected best ZD-inversion results to form a composite inversion result. The formation property of the subsurface formation is determined using the composite inversion result.

主权项

1. A method to determine a formation property of a subsurface formation, comprising:
providing a downhole logging tool having two or more tri-axial antennas; placing the downhole logging tool having two or more tri-axial antennas into a wellbore; obtaining azimuthally sensitive data using the antennas of the downhole logging tool; performing borehole correction on the obtained data; performing a zero dimensional inversion on the borehole corrected data for all antennal spacing groups;determining a formation indicator flag;
performing a 1D-axial inversion and/or a 1D radial inversion over selected zones, or neither, based on the determined formation indicator flag; selecting the best zero dimensional inversion results; combining the 1D-axial inversion results and/or the 1D-radial inversion results, if any, with the selected best zero dimensional inversion results to form a composite inversion result; and determining the formation property of the subsurface formation using the composite inversion result.