Continuous Orientation Measurement Systems Improve Reliability and Accuracy During Coring Operations

Charles Brindley

Complex new field developments and in-fill drilling programs have placed extra emphasis on the work conducted by an oil company's geological and petrophysical departments. Core samples retrieved from the well bore are a key source of data to these groups. Secondary and tertiary recovery projects have placed an extra premium on core samples being oriented.

The traditional survey instrument used to measure the in-situ orientation of a core as it is being cut has been the mechanical film-recording system developed for borehole deviation measurements. This system placed certain risks on the drilling operation, as it was necessary to stop drill-string rotation and fluid circulation to make the orientation measurements.

Solid-state transducer development has led to the development of electronic survey tools as replacements for the mechanical systems. Of primary importance to any drilling operation is the ability to use these tools in a continuous mode. The risks are negated, making the impact of running orientation as part of the coring operation nil.

Electronic survey tools have been used for core orientation measurements on over 70 wells worldwide to date.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.