About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 69 (1985)

Issue: 9. (September)

First Page: 1424

Last Page: 1424

Title: Evaluation of Radioelement Geochemistry for Detection of Petroleum Reservoirs: ABSTRACT

Author(s): D. Jay Johnson, Jerry Alliger, Robert K. Aaker

Article Type: Meeting abstract


We tested the hypothesis that radioelements are either enriched or depleted over petroleum accumulations. Total count surveys are subject to signal variations due to changes in Previous HitsoilNext Hit composition and to variations in Previous HitsoilNext Hit moisture. Methods have been determined to lower the variations due to Previous HitsoilNext Hit composition and to eliminate variations due to Previous HitsoilNext Hit moisture. We conclude that, if hydrocarbon-related anomalies are present, they are overwhelmed by changes in Previous HitsoilNext Hit composition.

Changes in Previous HitsoilNext Hit composition can cause: (1) a fourfold change in total count and eU, (2) a twofold change in K, and (3) a thirteenfold change in eTh. Modified eU/K, eTh/K, and eU/eTh ratios reduce the variations caused by Previous HitsoilNext Hit composition to ±50% of normal conditions. This permits detection of anomalies as low as 1.0 ppm eU, 2.0 ppm eTh, or 0.7% K. Statistical detection limit for the surveys is ±0.24 ppm eU at 2.0 ppm eU concentration.

The detected anomalies are of equal amplitude and frequency both on and off the fields. This, plus the lack of anomaly repeatability from line to line, precludes a hydrocarbon source. The majority of all anomalies are attributed to Previous HitsoilTop or lithologic sources. The others are caused by uranium mineralization.

End_of_Article - Last_Page 1424------------

Copyright 1997 American Association of Petroleum Geologists