Environmental correction of gamma ray logs by geometrical / empirical factors

Díaz-Curiel, Jesús; Miguel, María Jesús; Biosca, Bárbara; Medina, Rafael

doi:10.1016/j.petrol.2018.10.056

Cited by 7 publications

(7 citation statements)

References 8 publications

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“…As in many scientific fields, another widespread way to achieve the aforementioned predictive nature in geoscience involves mathematical modelling using finite element or finite difference methods, the main limitation of which is that they must be considered for each specific case. The theoretical starting point is sometimes limited when applying these techniques; for example, in the Monte Carlo modelling of radioactive spreading in subsoil, the effect of accumulation is not considered [7]. The same occurs in the modelling of flow in porous media when considering a tortuosity expression that does not reflect the real tortuosity [13].…”

Section: Knowledge-based Approaches In Geosciencesmentioning

confidence: 99%

“…Although the developed relationships have already been published in specialised journals in geosciences [3][4][5][6][7], it is important to note that the intention of presenting examples is not to review the published works but, rather, to show the physical scope of the algebraic function y 2A (x) in different phenomena. In each example, the limitations of the existing relationships and a brief description of the contribution of the new formulas are included.…”

Section: Examples Of New Empirical Laws From Y 2a (X)mentioning

confidence: 99%

“…The study then focuses on showing the established function type, named functions of double asymptote y 2A (x), specifically designed to model natural phenomena involving two different behaviours depending on changes in a single variable x. Some empirical relationships developed and published by authors in recent years in sufficiently differentiated fields: petrophysics [3], fluid flow in porous media [4], geotechnics [5], nuclear magnetic resonance [6], and spread of radioactive emissions [7] are presented as examples. In the discussion, some possible generic objections against the development of new empirical relationships are presented.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

New Empirical Laws in Geosciences: A Successful Proposal

Díaz-Curiel,

Biosca,

Arévalo-Lomas

et al. 2023

Applied Sciences

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The importance of empirical versus theoretical laws is a controversial issue in many scientific fields, the latter being generally accepted and the relevance of which is not discussed here. As in other areas, there are well-known theoretical and empirical formulas in geosciences that do not adequately represent the reality of a given phenomenon. Quantitative comparison of geophysical and petrophysical results with data from the other multiple fields that comprise the geosciences compels a high exigency to avoid discontinuities in existing relationships. However, the proposal of new empirical laws that more accurately reflect a given phenomenon is often considered insufficient to contradict existing formulas. The aim of this work is to defend the development of new empirical laws by showing that they constitute a true model of analysed behaviour if certain criteria are followed. This defence is especially needed when non-linearisable functions are required to fit the empirical data. To achieve this aim, this study shows the established algebraic function as a function of a single variable, whose main advantage is its application to phenomena of a geological nature that show two differentiated behaviours as the variable x is increased. A series of five examples of different phenomena related to geosciences is selected to demonstrate the level of accuracy that new empirical laws can reach in contrast to the widely accepted historical relationships.

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Section: Knowledge-based Approaches In Geosciencesmentioning

confidence: 99%

Section: Examples Of New Empirical Laws From Y 2a (X)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

New Empirical Laws in Geosciences: A Successful Proposal

Díaz-Curiel,

Biosca,

Arévalo-Lomas

et al. 2023

Applied Sciences

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“…The GR log reflects the total radiation of equivalent uranium (eU), equivalent thorium (eTh), and potassium (K) within a certain formation. These radioactive elements are contained sediments in the form of accessory minerals (Ellis and Singer 2007;Díaz-Curiel et al 2019). The GR curve reflects the total radiation of the mentioned elements, which have different energy peaks that are equivalent to 1.46 MeV, 1.76 MeV, and 2.62 MeV for K, U, and Th, respectively (Blum et al 1997;Ellis and Singer 2007;Skupio et al 2019).…”

Section: Electrofacies Interpretation From Gr Logmentioning

confidence: 99%

Modeling the Depositional Environment of the Sandstone Reservoir in the Middle Miocene Sidri Member, Badri Field, Gulf of Suez Basin, Egypt: Integration of Gamma-Ray Log Patterns and Petrographic Characteristics of Lithology

Radwan

2020

Nat Resour Res

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Understanding the depositional setting of siliciclastics reservoir is fundamental process to exploration and development of hydrocarbon reservoirs and to the multi-phase cycle of the oil and gas industry. Typically, core samples from existing or potential reservoirs can be used for interpretation of depositional environment. However, the lack of core samples in certain reservoirs represents a challenge for reservoir development plans and further exploration. To overcome the absence of core samples in the middle Miocene Sidri Member in the Badri field, Gulf of Suez, this study aimed to reconstruct its depositional settings by coupling well logging patterns and petrographic characterization of ditch cuttings. Consequently, 30 thin section samples representing the reservoir section of four wells were described in detail and standard petrographic characteristics were determined. Then, gamma-ray (GR) log patterns of the studied reservoir wells were used for interpretation of depositional environment. Petrographic analysis indicates that the sandstone reservoir is fine- to medium-grained arkose with dominant siliceous cement and composed mainly of quartz, feldspars, and lithic fragments. Pores reflecting primary and secondary porosity as well as inter-granular pores are dominant. The facies analysis indicates that the studied member has a heterogeneous nature and rapid facies change; its main lithofacies are blocky sandstones, intercalated sandstones and shales, and shales. Three electrofacies were interpreted in the studied section: (1) electrofacies-A (blocky sandstones), which is characterized by a cylindrical-shaped (right boxcar) GR trend; (2) electrofacies-B (intercalated sandstones and shales), which is characterized by an irregular log trend with serrated shape; and (3) electrofacies-C (shales), which is characterized by irregular GR trend and has no character. The interpreted results indicate a tidal channel depositional setting for electrofacies-A, mixed tidal flat depositional setting for electrofacies-B, and low relief offshore mudstone depositional setting for electrofacies-C. Finally, the results illustrate how the coupling of GR patterns with the analysis of petrographic characteristics can be used to understand the depositional setting of a hydrocarbon reservoir that lacks core samples. This work could be useful for assessment of reservoir distribution and quality, for reduction of uncertainty during field development, as well as for providing useful insight to similar hydrocarbon reservoirs elsewhere.

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“…The gamma ray measurements (GR) are used as a foundation in quantifying shale volume, what allows for lithological interpretation and zone correlation from well to well (Díaz-Curiel et al 2019). Gamma ray emission from the rocks is related with the presence of naturally radioactive clays and ions associated with them (Ellis and Singer 2007).…”

Section: Introductionmentioning

confidence: 99%

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

Skupio

Kubik

Wolański³

2019

Acta Geophys.

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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.

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Environmental correction of gamma ray logs by geometrical / empirical factors

Cited by 7 publications

References 8 publications

New Empirical Laws in Geosciences: A Successful Proposal

New Empirical Laws in Geosciences: A Successful Proposal

Modeling the Depositional Environment of the Sandstone Reservoir in the Middle Miocene Sidri Member, Badri Field, Gulf of Suez Basin, Egypt: Integration of Gamma-Ray Log Patterns and Petrographic Characteristics of Lithology

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

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