Method and apparatus for correcting data developed from a well tool disposed at a dip angle in a wellbore to eliminate the effects of the dip angle on the data
US5184079A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 13, 1990 |
| Grant date | Feb 2, 1993 |
| Priority date | — |
| Expiry date | Nov 13, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a well logging truck computer which phroduces an induction log, a dip correction algorithm, stored in a memory of the computer, corrects an error introduced in the induction log by dip effect. The dip effect error is introduced into the induction log when an array induction tool is disposed in a deviated borehole at an apparent dip angle with respect to a formation having a plurality of bedding planes, and subsequently develops formation parameter data. This formation parameter data, which contains the dip effect error, is displayed on the induction log. The dip effect algorithm eliminates the dip effect error by multiplying or convolving inverse filters "h" as a function of dip angle "a" with a plurality of the formation parameter data "sigma(j-n)" to thereby produce a corresponding plurality of corrected formation parameter data "sigma.sub.F ", the corrected formation parameter data being reproduced on an induction log output record medium. The inverse filters "h" are computed using log response functions derived from simple dipping formation models.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.