thumbnail

True location and orientation of fractures logged with the acoustic televiewer (including programs to correct fracture orientation)

Water-Resources Investigations Report 83-4275

By:

Links

Abstract

The attitude of fractures measured on acoustic-televiewer logs may be misorientated by as much as 180 degrees in a drill hole that is deviated significantly from vertical, because of the effect of the vertical component of the magnetic field on the tilted magnetometer that is used to orient the log. A method has been developed to correct for the misorientation by analyzing the orientation of the magnetometer with respect to the magnetic-field vector acting at the magnetometer 's center. Computer programs were written to correct the attitude of fractures for both magnetic effects and hole deviation. For the reorientation of a single fracture, a stereographic solution is illustrated. Test results suggest that the fracture orientation can be corrected to plus or minus five degrees of true orientation, provided there are no other magnetic effects, such as magnetite in the rocks. (USGS)

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
True location and orientation of fractures logged with the acoustic televiewer (including programs to correct fracture orientation)
Series title:
Water-Resources Investigations Report
Series number:
83-4275
Edition:
-
Year Published:
1984
Language:
ENGLISH
Publisher:
U.S. Geological Survey,
Description:
iv, 73 p. :ill. ;28 cm.