The integration of core and borehole image log data using core goniometry

Abstract

Summary Core goniometry is an established technique. However, the explosion of borehole imaging that occurred in the 1990’s onwards corresponded somewhat with a decline in the acquisition of cores by operating companies. Borehole images were acquired over much longer intervals than cores, and provided cost effective high resolution oriented data-sets. However, an increasing shift to drilling wells with non-conductive mud systems over the last decade has countered this to a degree, and there appears to be increased or renewed interest in using cores to undertake core goniometry to derive high resolution oriented datasets. This has in part been driven by the limitations common in some earlier generations of imaging tools developed for use in non-conductive borehole environments. In such cases, core goniometry can provide very significant increases in data density compared to borehole images, enabling highly detailed sedimentological and structural interpretation. 10-fold increases in dip data density are possible. The paper will summarize some of the techniques that can be used for core goniometry, demonstrating the orientation principle using Task Fronterra’s attitude software, and outlining the types of “core versus log” data density variations, together with benefits and limitations that may be encountered.