Summary

Microconductivity array and acoustic imaging of the borehole wall provides valuable mulidatasets of information which are applied to characterize the geological strata and especially the reservoirs in exploration activities and during development of producing zones.

This paper presents a tutorial to the main applications and methodology to follow when performing fracture interpretations. Borehole imaging data should not be a routine work referring to “kitchen rules”. It must rely on our geological and structural knowledge and experience, on basic notions about tools principles and to image processing and on geometrical calibrations to cores.

Through various examples, we will see:

 Natural open fractures: how to distinguish them from drilling-induced fractures,

 Typical drilling-induced fractures associated to borehole breakouts; how to identify them and their significance,

 Tricky case: when cemented fractures might be confused with open ones.

As interpretation support, high resolution borehole images will be integrated with unrolled core photographs for geometrical orientation of geological features.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah