The sedimentology of Lower Palaeozoic black shales from the shallow wells Skelbro 1 and Billegrav 1, Bomholm, Denmark

Previous studies of the Lower Palaeozoic shales on Bornholm have mainly been based on the outcrops along the streams. The outcrops provide data on the lateral continuity of the facies while the selection of (2-3 cm wide) cores for the present study focused the attention on the vertical sequence of facies. Cores of high quality were obtained and have been found to provide an excellent basis for a study of structures, sediment composition and diagenesis. In the outcrops of shale fossils are locally present in high numbers and such levels are also recognized in the cores. Seven sedimentary facies, ranging from black mudshale to greyish mudstone and silt-streaked shale, are distinguished in the Middle Cambrian to lowermost Silurian shales. Gamma-ray logs were run in the two wells and a convincing correlation to the cored sequence can be demonstrated. Gamma-ray logs provide thus a good means of correlation to wells where no cores have been cut. The shales are all interpreted as deposited in an epicontinental sea due to their geological setting i.e. the association with shallow water carbonates (Andrarum Limestone and Komstad Limestone) and their stratigraphical position above the shelf to shoreface sandstones of the Lresa formation. Three facies associations are distinguished: The mudshale association comprises black organic-rich shales which represent a low-energy anoxic depositional environment which prevailed in the Middle Cambrian to Lower Ordovician. The mudstone association is typical of the Middle and Upper Ordovician and represents a continuation of low-energy environments though mottling indicates that ventilation improved in certain periods. The siltshale association represents higher energy environments which were dominant in the lowermost Silurian. A well defined Upper Ordovician CU sequence probably reflects the global eustatic fall in sea level caused by the extensive glaciation in Gondwanaland. In the late Silurian the average rate of deposition increased in response to the approaching Caledonian orogeny.

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Interpretation and Reconstruction of Depositional Environment and Petroleum Source Rock Using Outcrop Gamma-ray Log Spectrometry From the Huai Hin Lat Formation, Thailand

Frontiers in Earth Science ◽

10.3389/feart.2021.638862 ◽

2021 ◽

Vol 9 ◽

Author(s):

Chawisa Phujareanchaiwon ◽

Piyaphong Chenrai ◽

Kasira Laitrakull

Keyword(s):

Depositional Environment ◽

Gamma Ray ◽

Sedimentary Facies ◽

Depositional Environments ◽

Turbidity Currents ◽

Stratigraphic Framework ◽

Facies Associations ◽

Mineral Compositions ◽

Gamma Ray Log ◽

Low K

Gamma ray logs are most useful in identifying subsurface lithology and interpreting depositional environments. This study highlights the use of outcrop gamma-ray logs along with outcrop observations and total organic carbon (TOC) analysis to provide the stratigraphic framework of the organic-rich rocks of Huai Hin Lat Formation in central Thailand. The study reveals five sedimentary facies including (1) structureless sandstone, (2) structured sandstone, (3) interbedded sandstone and siltstone, (4) interbedded mudstone and siltstone and (5) calcareous mudstone. These facies can be grouped into two facies associations; mudstone-dominated and sandstone-dominated facies associations. The depositional environment was interpreted as lacustrine basin-fill subdivided into deep lacustrine environment and sublacustrine fan associated with the turbidity currents. The total gamma-log characteristics are closely related to the lithologies controlled primarily by clay mineral compositions. Whist, the use of spectral gamma-ray can reveal more details on depositional environments and conditions. In this study, U concentrations is proven to be useful in highlighting organic-rich rocks in low K and Th concentration successions due to its ability to be fixed in clay minerals and organic materials under an anoxic condition. Thus, the U spectral gamma ray is suggested to combine with conventional gamma ray log for depositional environment and recognition of organic-rich rocks.

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Limits on quantum gravity effects from Swift short gamma-ray bursts

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731332 ◽

2017 ◽

Vol 607 ◽

pp. A121 ◽

Cited By ~ 5

Author(s):

M. G. Bernardini ◽

G. Ghirlanda ◽

S. Campana ◽

P. D’Avanzo ◽

J.-L. Atteia ◽

...

Keyword(s):

Quantum Gravity ◽

Gamma Ray ◽

Lorentz Invariance ◽

Spectral Energy Distribution ◽

Gamma Ray Bursts ◽

Low Energy ◽

Energy Separation ◽

Spectral Energy ◽

Spectral Evolution ◽

Short Grbs

The delay in arrival times between high and low energy photons from cosmic sources can be used to test the violation of the Lorentz invariance (LIV), predicted by some quantum gravity theories, and to constrain its characteristic energy scale EQG that is of the order of the Planck energy. Gamma-ray bursts (GRBs) and blazars are ideal for this purpose thanks to their broad spectral energy distribution and cosmological distances: at first order approximation, the constraints on EQG are proportional to the photon energy separation and the distance of the source. However, the LIV tiny contribution to the total time delay can be dominated by intrinsic delays related to the physics of the sources: long GRBs typically show a delay between high and low energy photons related to their spectral evolution (spectral lag). Short GRBs have null intrinsic spectral lags and are therefore an ideal tool to measure any LIV effect. We considered a sample of 15 short GRBs with known redshift observed by Swift and we estimate a limit on EQG ≳ 1.5 × 1016 GeV. Our estimate represents an improvement with respect to the limit obtained with a larger (double) sample of long GRBs and is more robust than the estimates on single events because it accounts for the intrinsic delay in a statistical sense.

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C-SPRINT: a prototype Compton camera system for low energy gamma ray imaging

1997 IEEE Nuclear Science Symposium Conference Record ◽

10.1109/nssmic.1997.672602 ◽

2002 ◽

Cited By ~ 7

Author(s):

J.W. LeBlanc ◽

N.H. Clinthorne ◽

C.-H. Hua ◽

E. Nygard ◽

W.L. Rogers ◽

...

Keyword(s):

Gamma Ray ◽

Low Energy ◽

Compton Camera ◽

Camera System ◽

Gamma Ray Imaging ◽

Energy Gamma

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Measurement of Low-Energy Gamma-Ray Pair Cross Sections in Scintillators Using a Scintillation Pair Spectrometer

Physical Review ◽

10.1103/physrev.101.915 ◽

1956 ◽

Vol 101 (3) ◽

pp. 915-921 ◽

Cited By ~ 22

Author(s):

Harry I. West

Keyword(s):

Cross Sections ◽

Gamma Ray ◽

Low Energy ◽

Energy Gamma

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Constraints on the late X-ray radiation from the low-energy gamma-ray burst of December 3, 2003: INTEGRAL data

Astronomy Letters ◽

10.1134/s1063773706050021 ◽

2006 ◽

Vol 32 (5) ◽

pp. 297-301 ◽

Cited By ~ 1

Author(s):

S. Yu. Sazonov ◽

A. A. Lutovinov ◽

E. M. Churazov ◽

R. A. Sunyaev

Keyword(s):

Gamma Ray ◽

Low Energy ◽

Gamma Ray Burst ◽

X Ray ◽

Energy Gamma ◽

Integral Data

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NMR contribution in sub-horizontal well for porosity-permeability heterogeneity characterization in limestones: implications for 3D reservoir prediction and flow simulation in a world class geothermal aquifer

10.5194/egusphere-egu21-1101 ◽

2021 ◽

Author(s):

Maxime Catinat ◽

Benjamin Brigaud ◽

Marc Fleury ◽

Miklos Antics ◽

Pierre Ungemach ◽

...

Keyword(s):

Geothermal Energy ◽

Horizontal Well ◽

Gamma Ray ◽

Flow Simulation ◽

High Density ◽

Reservoir Prediction ◽

Nmr Data ◽

Geothermal Potential ◽

Facies Associations ◽

Deep Geothermal Energy

With around 50 heating networks today operating, the aera around Paris is the European region which concentrates the most heating network production units in terms of deep geothermal energy. In France, the energy-climate strategy plans to produce 6.4TWh in 2023, compared to 1.5TWh produced in 2016. Despite an exceptional geothermal potential, the current average development rate of 70MWh/year will not allow this objective to be achieved, it would be necessary to reach a rate of 6 to 10 times higher. The optimization of the use of deep geothermal energy is a major challenge for France, and in Ile-de-France, which has a population of nearly 12 million inhabitants. This project aims to reconstruct and simulate heat flows in the Paris Basin using an innovative methodology (1) to characterize, predict and model the properties of reservoirs (facies, porosity, permeability) and (2) simulate future circulations and predict the performance at a given location (sedimentary basin) on its geothermal potential. This study focuses on a high density area of well infrastructures around Cachan, (8 doublets, 1 triplet in 56 km2). A new sub-horizontal doublet concept has been recently (2017) drilled at Cachan to enhance heat exchange in medium to low permeability formations. Nuclear Magnetic Resonance (NMR T2) logs have been recorded in the sub-horizontal well (GCAH2) providing information on pore size distribution and permeability. We integrated all logging data (gamma ray, density, resistivity, sonic, NRM T2) of the 19 wells in the area and 120 thin section observations from cuttings to derive a combined electrofacies-sedimentary facies description. A total of 10 facies is grouped into 5 facies associations coded in all the 19 wells according to depths and 10 3rd order stratigraphic sequences are recognized. The cell size of the 3D grid was set to 50 m x 50 m for the XY dimensions. The Z-size depends on the thickness of the sub-zones, averaging 5 m. The resulting 3D grid is composed of a total of nearly 8.105cells. After upscaled, facies and stratigraphic surfaces are used to create a reliable model using the &#8220;Truncated Gaussian With Trends&#8221; algorithm. The petrophysical distribution &#8220;Gaussian Random Function Simulation&#8221; is used to populate the entire grid with properties, included 2000 NMR data, considering each facies independently. The best reservoir is mainly located in the shoal deposits oolitic grainstones with average porosity of 12.5% and permeability of 100 mD. Finally, hydrodynamic and thermal simulations have been performed using Pumaflow to give information on the potential risk of interference between the doublets in the area and advices are given in the well trajectory to optimize the connectivity and the lifetime of the system. NMR data, especially permeability, allow to greater improve the simulations, defining time probabilities of thermal breakthrough in an area of high density wells.

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Systematic Low-Energy Enhancement of the Gamma-Ray Strength Function

Springer Proceedings in Physics - Nuclei in the Cosmos XV ◽

10.1007/978-3-030-13876-9_76 ◽

2019 ◽

pp. 405-407

Author(s):

J. E. Midtbø ◽

A. C. Larsen ◽

T. Renstrøm ◽

F. L. Bello Garrote ◽

E. Lima

Keyword(s):

Gamma Ray ◽

Strength Function ◽

Low Energy

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Radionuclides in fly ash and bottom ash: improved characterization based on radiography and low energy gamma-ray spectrometry

Fuel ◽

10.1016/s0016-2361(97)00194-4 ◽

1998 ◽

Vol 77 (4) ◽

pp. 259-267 ◽

Cited By ~ 37

Author(s):

Robert A. Zielinski ◽

James R. Budahn

Keyword(s):

Fly Ash ◽

Gamma Ray ◽

Bottom Ash ◽

Low Energy ◽

Gamma Ray Spectrometry ◽

Energy Gamma

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Depositional, diagenetic and stratigraphic aspects of Macaé Group carbonates (Albian): example from an oilfield from Campos Basin

Brazilian Journal of Geology ◽

10.1590/23174889201500020005 ◽

2015 ◽

Vol 45 (2) ◽

pp. 243-258 ◽

Cited By ~ 11

Author(s):

Juliana Okubo ◽

Ricardo Lykawka ◽

Lucas Veríssimo Warren ◽

Julia Favoreto ◽

Dimas Dias-Brito

Keyword(s):

Deep Water ◽

Carbonate Rocks ◽

Facies Analysis ◽

Sedimentary Facies ◽

Fair Weather ◽

Thin Sections ◽

Carbonate Sedimentation ◽

Diagenetic Processes ◽

Campos Basin ◽

Facies Associations

Carbonate rocks from the Macaé Group (Albian) represent an example of carbonate sedimentation related to the drift phase in Campos Basin. This study presents depositional features, integrating them with diagenetic and stratigraphic aspects of the Macaé Group carbonates including the upper part of the Quissamã Formation and the lower part of the Outeiro Formation. Macroscopic analyses in cores and microscopic ones in thin sections allowed the recognition of eleven sedimentary facies - nine of them corresponding to the Quissamã Formation and two of them representing the Outeiro Formation. These facies were grouped into five facies associations. Oolitic grainstones and oncolitic grainstones are interpreted to be deposited in shallow depth probably in shoals above the fair weather wave base. The interbanks between shoals were formed in less agitated waters and characterized by deposition of peloidal bioclastic packstones and wackestones representative of sedimentation in calm waters. Bioclastic packstones and oolitic packstones/wackestones represent allochthonous deposits related to the beginning of the regional drowning that occur in upper Quissamã Formation. Pithonellids wackestones and bioclastic wackestones with glauconite are related to deep water deposits, characteristics of the Outeiro Formation. Post-depositional features revealed the action of diagenetic processes as, micritization, cimentation, dissolution, compaction, dolomitization and recrystallization occurred during the eo- and mesodiagenesis phases. Vertical facies analysis suggests shallowing upward cycles stacked in a sequence progressively deeper towards the top (from the Quissamã Formation to the Outeiro Formation).

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