CROSS-COUPLING BASED DETERMINATION OF ANISOTROPIC FORMATION PROPERTIES

摘要

Tools, systems, and methods are disclosed for multi-component induction logging with iterative analytical conversion of tool measurements to formation parameters. At least some system embodiments include a logging tool and at least one processor. The logging tool provides transmitter-receiver coupling measurements that include at least diagonal coupling measurements (Hzz, Hxx, and/or Hyy) and cross-coupling measurements (Hxy, Hxz, and Hyz). The processor employs an iterative analytical conversion of the cross-coupling measurements into formation resistive anisotropy and dip information. The processor may further provide one or more logs of the resistive anisotropy and/or dip information.

主权项

1. A logging method that comprises:
conveying a logging tool along a borehole through a formation to gather multi-component transmitter-receiver coupling measurements including diagonal coupling measurements and cross-coupling measurements; obtaining from the cross-coupling measurements and not from the diagonal coupling measurements: a strike angle, an initial dip angle, an initial anisotropy factor, and an initial conductivity; determining from the cross-coupling measurements, the strike angle, the latest dip angle, and the latest anisotropy factor, and the latest conductivity: an iterative anisotropy factor, an iterative conductivity, and an iterative dip angle; and providing a log based at least in part on at least one of said iterative values.