[First Hit]

Datapages, Inc.Print this page

Previous HitResistivityNext Hit Calibration Technique for Micro-Previous HitResistivityNext Hit Image Logs: Applications for Thin-Bedded, Shaly Sand Reservoirs, Gulf of Mexico


A new technique is presented for calibrating Previous HitresistivityNext Hit measurements recorded by micro-Previous HitresistivityNext Hit image devices. This technique involves converting the recorded electrical power measurements to a scaled true Previous HitresistivityNext Hit. The scaled micro-Previous HitresistivityNext Hit curve represents an average of multiple sensors on a given pad or pad and flap combination. This scaled average curve agrees well with standard electric log shallow Previous HitresistivityNext Hit measurements over equivalent intervals. The scaled image log allows for accurate and quantitative Previous HitresistivityNext Hit comparisons that is not possible with the standard processed image logs.

Pseudo-color borehole images were generated from the scaled micro-Previous HitresistivityNext Hit curves and compared with core data from two offshore Gulf of Mexico fields to evaluate their reliability. Dynamic normalization image enhancement techniques resulted in greater resolution of Previous HitapparentNext Hit stratigraphic details in the uncalibrated images. Dynamic normalized uncalibrated images may reflect real Previous HitresistivityNext Hit variations in the well bore, resolving subtle textural variations in grain size and clay morphology, and thus may be preferred for certain log interpretation applications. The calibrated images exhibited better correlation to lithologic features observed from the cores. The scaled images allow for quantitative Previous HitresistivityTop variations which may be useful in characterizing hydrocarbon saturations within the flushed zone of the wellbore. The scaled images are preferred for net pay and net sand counts within thin-bedded shaly sand reservoirs.

AAPG Search and Discovery Article #91021©1997 AAPG Annual Convention, Dallas, Texas.