دورية أكاديمية
Spectral gamma-ray signature of fluvial deposits: a case study from the Late Permian Rio do Rasto Formation, Paraná Basin, Brazil
| العنوان: | Spectral gamma-ray signature of fluvial deposits: a case study from the Late Permian Rio do Rasto Formation, Paraná Basin, Brazil |
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| المؤلفون: | Guilherme Arruda Sowek, Francisco José Fonseca Ferreira, Fernando Farias Vesely, Fabio Berton |
| المصدر: | Geologia USP. Série Científica, Vol 13, Iss 3, Pp 83-98 (2013) |
| بيانات النشر: | Universidade de São Paulo, 2013. |
| سنة النشر: | 2013 |
| المجموعة: | LCC:Geology |
| مصطلحات موضوعية: | Fuvial deposits, Gamma-ray logs, Outcrop analogs, Rio do Rasto Formation, Paraná Basin, Geology, QE1-996.5 |
| الوصف: | Fluvial channel-fill deposits form highly heterogeneous hydrocarbon reservoirs. The study of outcrop analogs can help in the characterization of these heterogeneities, which are usually not detected by subsurface geophysical methods. The aim of this research is to compare outcrop log signatures with grain size trends and depositional elements of the fluvial deposits of the Late Permian Rio do Rasto Formation. A series of vertical gamma-ray logs were assembled in two outcrops in order to: 1) characterize log-facies in a succession composed of alternated flood plain, channel fill and eolian strata; 2) define within-channel spectral gamma-ray variability of a mixed-load composite point bar deposit and its relationship with grain size trends and lithofacies; 3) correlate log signatures observed in the outcrop sections with deep exploratory wells drilled several tens of kilometers from the study area. The results of this study show that gamma-ray logs have good correlation with grain size trends and that different depositional elements have distinct signatures. On the other hand, point bar deposits exhibit strong lateral changes in log signature due variations in grain size and mud content within lateral accretion strata. Although frequent, the classic bell-shaped log motif was not always detected, which means that the amount of fluvial channel-fill deposits recognized in subsurface can be underestimated. Similar log signatures were detected in the boreholes, at least in the closest ones, helping in paleoenvironmental interpretation in the subsurface. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English Portuguese |
| تدمد: | 1519-874X |
| Relation: | http://ppegeo.igc.usp.br/pdf/guspsc/v13n3/a07v13n3.pdf; https://doaj.org/toc/1519-874X |
| DOI: | 10.5327/Z1519-874X201300030008 |
| URL الوصول: | https://doaj.org/article/d5f526a4691d4b139b6356a5afdfb3be |
| رقم الأكسشن: | edsdoj.5f526a4691d4b139b6356a5afdfb3be |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 1519874X |
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| DOI: | 10.5327/Z1519-874X201300030008 |