An Improved Algorithm for Spinner Profile Analysis

Abstract

A new approach to the analysis of spinner data is proposed, where the complete set of data (depth, tool velocity, frequency) is regarded as a single set of observationsto be fitted to a model of fluid structure (depth,fluid velocity) and a model of tool performance. This approach of treating the entire data set on the same basis is considered to be better than previous methods and more consistentmathematical practice. Multiple observationsat calibration stations count in proportion to their number, but repeat observations at other depths contribute equally to the tool model or If measurementsonly at a fixed station are considered, the approach is identical to standard calibration cross-plotting.

This analysis method generates fioma set of measurements at different tool velocities, a single best estimate of fluid velocity against depth. This can be subjectivelyinterpreted. Such interpretationsare free of tool bias. If multiple flow rates have been used, a velocity profile is generated for each flow rate. Comparison between these velocity profiles can be used to generatea model of well diameter and feed zone structure.