Archival gamma ray logs standardization by nondestructive core measurements of the low-radioactivity rocks

Acta Geophysica

article

Skupio, Rafał¹  Kubik, Benedykt¹  Wolański, Krzysztof² 

[1] Well Logging Department, Oil and Gas Institute – National Research Institute;Polish Oil and Gas Company

关键词: Rotliegend;    Core logging;    Well logging;    Gamma radiation;    Spectrometry;   

DOI  :  10.1007/s11600-019-00340-z

学科分类：地球科学(综合)

来源: Polska Akademia Nauk * Instytut Geofizyki

【 摘 要 】

The present study analyzes spectral gamma ray data of low-radioactivity rock cores from Rotliegend Basin. The main goal of this research was standardization of archival gamma ray logs measured in counts per minute to American Petroleum Institute units. Selected core intervals, log data, and additional crushed samples covered three different boreholes: J-1, L-7, and K-2 from Zielona Góra Basin, localized in western Poland, where J-1 was a reference borehole. Core measurements were performed on the sandstone and conglomerate formations by Gamma Logger GT spectrometer, which uses two scintillation detectors containing bismuth germanate crystals. In the cores, real concentrations of potassium, uranium, and thorium were acquired what enabled to calculate total content of radioactive elements and total uninfluenced by uranium. Delivered new total GR_GLGT curve from cores allowed accurate standardization of archival GR curves from L-7 and K-2 boreholes. Presented results showed a very good correlation between logs, core data, and laboratory analyses. These data allow precise shale volume reinterpretation.

【 授权许可】

Unknown