scholarly journals Diagenetic Processes and Reservoir Heterogeneity in Salt-Encased Microbial Carbonate Reservoirs (Late Neoproterozoic, Oman)

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Stephan Becker ◽  
Lars Reuning ◽  
Joachim E. Amthor ◽  
Peter A. Kukla
Keyword(s):  
Carbonate Reservoirs ◽  
Salt Diapir ◽  
Strong Impact ◽  
Field Scale ◽  
Reservoir Properties ◽  
Heterogeneous Distribution ◽  
Near Surface ◽  
Porosity Reduction ◽  
Diagenetic Processes ◽  
The Impact

A common problem in dolomite reservoirs is the heterogeneous distribution of porosity-reducing diagenetic phases. The intrasalt carbonates of the Ediacaran-Early Cambrian Ara Group in the South Oman Salt Basin represent a self-sourcing petroleum system. Depositional facies and carbonate/evaporite platform architecture are well understood, but original reservoir properties have been modified by diagenesis. Some of the carbonate reservoirs failed to produce hydrocarbons at acceptable rates, which triggered this study. The extent of primary porosity reduction by diagenetic phases was quantified using point counting. To visualize the distribution of diagenetic phases on a field scale, we constructed 2D interpolation diagenesis maps to identify patterns in cementation. The relative timing of diagenetic events was constrained based on thin-section observations and stable isotope analyses. Near-surface diagenesis is dominated by reflux-related processes, leading to porosity inversion in initial highly porous facies and a patchy distribution of early cements. This strong diagenetic overprint of primary and early diagenetic porosity by reflux-related cements leads to a reduction of stratigraphic and facies control on porosity. Calcite was identified as a burial-related cement phase that leads to an almost complete loss of intercrystalline porosity and permeability. Bitumen is an important pore-occluding phase and time marker of the deep-burial realm. The stratigraphic position of the dolomite reservoirs embedded at the base of a salt diapir had a strong impact on its diagenetic development. The salt isolated the dolomites from external fluids, leading to a closed system diagenesis and the buildup of near lithostatic fluid pressures. In combination, these processes decreased the impact of further burial diagenetic processes. The study highlights that cement distribution in salt-encased carbonate reservoirs is mainly related to early diagenetic processes but can be very heterogeneous on a field scale. Further work is needed to implement these heterogeneities in an integrated numerical reservoir model.

scholarly journals Impact of surface and near-surface processes on ice crystal concentrations measured at mountain-top research stations

2017 ◽  
Author(s):  
Alexander Beck ◽  
Jan Henneberger ◽  
Jacob P. Fugal ◽  
Robert O. David ◽  
Larissa Lacher ◽  
...  
Keyword(s):  
Ice Crystals ◽  
Surface Processes ◽  
Strong Impact ◽  
Blowing Snow ◽  
Ice Crystal ◽  
Turbulent Layer ◽  
Near Surface ◽  
Orographic Clouds ◽  
The Impact

Abstract. In-situ cloud observations at mountain-top research stations regularly measure ice crystal number concentrations (ICNCs) orders of magnitudes higher than expected from measurements of ice nucleating particle (INP) concentrations. Thus, several studies suggest that mountain-top in-situ measurements are influenced by surface processes, e.g. blowing snow, hoar frost or riming on snow covered trees, rocks and the snow surface. A strong impact on the observed ICNCs on mountain-top stations by surface processes may limit the relevance of such measurements and possibly affects the development of orographic clouds. This study assesses the impact of surface processes on in-situ cloud observations at the Sonnblick Observatory in the Hohen Tauern Region, Austria. Vertical profiles of ICNCs above a snow covered surface were observed up to a height of 10 m. The ICNC decreases at least by a factor of two at 10 m, if the ICNC at the surface is larger than 100 L−1. This decrease can be up to one order of magnitude during in-cloud conditions and reached its maximum of more than two orders of magnitudes when the station was not in cloud. For one case study, the ICNC for regular and irregular ice crystals showed a similar relative decrease with height, which cannot be explained by the above mentioned surface processes. Therefore, two near-surface processes are proposed to enrich ICNCs and explain these finding. Either sedimenting ice crystals are captured in a turbulent layer above the surface or the ICNC is enhanced in a convergence zone, because the cloud is forced over a mountain. These two processes would also have an impact on ICNCs measured at mountain-top stations if the surrounding surface is not snow covered. Conclusively, this study strongly suggests that ICNCs measured at mountain-top stations are not representative for the properties of a cloud further away from the surface.

scholarly journals Testing geologic assumptions and scenarios in carbonate exploration: Insights from integrated stratigraphic, diagenetic, and seismic forward modeling

2018 ◽  
Vol 37 (9) ◽  
pp. 672-680 ◽  
Author(s):  
Cyprien Lanteaume ◽  
François Fournier ◽  
Matthieu Pellerin ◽  
Jean Borgomano
Keyword(s):  
Spatial Distribution ◽  
Forward Modeling ◽  
Reservoir Properties ◽  
Modeling Approaches ◽  
Diagenetic Processes ◽  
Stratigraphic Architecture ◽  
Carbonate Deposition ◽  
Seismic Models ◽  
Seismic Reflectors ◽  
The Impact

Carbonates are considered complex, heterogeneous at all scales, and unfortunately often poorly seismically imaged. We propose a methodology based on forward-modeling approaches to test the validity of common exploration assumptions (e.g., chronostratigraphic value of seismic reflectors) and of geologic interpretations (e.g., stratigraphic correlations and depositional and diagenetic architecture) that are determined from a limited amount of data. The proposed workflow includes four main steps: (1) identification and quantification of the primary controls on carbonate deposition and the prediction of the carbonate stratigraphic architecture (through stratigraphic forward modeling); (2) identification of diagenetic processes and prediction of the spatial distribution of diagenetic products (diagenetic forward modeling); (3) quantification of the impact of diagenesis on acoustic and reservoir properties; and (4) computation of synthetic seismic models based on various scenarios of stratigraphic and diagenetic architectures and comparison with actual seismic. The likelihood of a given scenario is tested by quantifying the misfit between the modeled versus the real seismic. This workflow illustrates the relevance of forward-modeling approaches for building realistic models that can be shared by the various disciplines of carbonate exploration (sedimentology, stratigraphy, diagenesis, seismic, geomodeling, and reservoir).

scholarly journals Influence of metallicity on the near-surface effect on oscillation frequencies

2018 ◽  
Vol 620 ◽  
pp. A107 ◽  
Author(s):  
L. Manchon ◽  
K. Belkacem ◽  
R. Samadi ◽  
T. Sonoi ◽  
J. P. C. Marques ◽  
...  
Keyword(s):  
Surface Effect ◽  
Strong Impact ◽  
Surface Layers ◽  
Frequency Spectra ◽  
Near Surface ◽  
Empirical Correction ◽  
Hydrodynamical Simulations ◽  
Oscillation Frequencies ◽  
High Degree ◽  
The Impact

Context. The CoRoT and Kepler missions have provided high-quality measurements of the frequency spectra of solar-like pulsators, enabling us to probe stellar interiors with a very high degree of accuracy by comparing the observed and modelled frequencies. However, the frequencies computed with 1D models suffer from systematic errors related to the poor modelling of the uppermost layers of stars. These biases are what is commonly named the near-surface effect. The dominant effect is thought to be related to the turbulent pressure that modifies the hydrostatic equilibrium and thus the frequencies. This has already been investigated using grids of 3D hydrodynamical simulations, which also were used to constrain the parameters of the empirical correction models. However, the effect of metallicity has not been considered so far. Aims. We aim to study the impact of metallicity on the surface effect, investigating its influence across the Hertzsprung-Russell diagram, and providing a method for accounting for it when using the empirical correction models. Methods. We computed a grid of patched 1D stellar models with the stellar evolution code CESTAM in which poorly modelled surface layers have been replaced by averaged stratification computed with the 3D hydrodynamical code CO5BOLD. It allowed us to investigate the dependence of both the surface effect and the empirical correction functions on the metallicity. Results. We found that metallicity has a strong impact on the surface effect: keeping Teff and log g constant, the frequency residuals can vary by up to a factor of two (for instance from [Fe/H] = + 0.0 to [Fe/H] = + 0.5). Therefore, the influence of metallicity cannot be neglected. We found that the correct way of accounting for it is to consider the surface Rosseland mean opacity. It allowed us to give a physically grounded justification as well as a scaling relation for the frequency differences at νmax as a function of Teff, log g and κ. Finally, we provide prescriptions for the fitting parameters of the most commonly used correction functions. Conclusions. We show that the impact of metallicity through the Rosseland mean opacity must be taken into account when studying and correcting the surface effect.

scholarly journals The impact of diagenesis on the reservoir quality of the early Cretaceous Lower Goru sandstones in the Lower Indus Basin, Pakistan

2021 ◽  
Author(s):  
Qamar UZ Zaman Dar ◽  
Renhai Pu ◽  
Christopher Baiyegunhi ◽  
Ghulam Shabeer ◽  
Rana Imran Ali ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Pore Space ◽  
Hydrocarbon Exploration ◽  
Indus Basin ◽  
Coarse Grained ◽  
Rock Properties ◽  
Reservoir Properties ◽  
Diagenetic Processes ◽  
Lower Indus Basin ◽  
The Impact

AbstractThe sandstone units of the Early Cretaceous Lower Goru Formation are significant reservoir for gas, oil, and condensates in the Lower Indus Basin of Pakistan. Even though these sandstones are significant reservoir rocks for hydrocarbon exploration, the diagenetic controls on the reservoir properties of the sandstones are poorly documented. For effective exploration, production, and appraisal of a promising reservoir, the diagenesis and reservoir properties must be comprehensively analyzed first. For this study, core samples from depths of more than 3100 m from the KD-01 well within the central division of the basin have been studied. These sandstones were analyzed using petrographic, X-ray diffraction, and scanning electron microscopic analyses to unravel diagenetic impacts on reservoir properties of the sandstone. Medium to coarse-grained and well-sorted sandstone have been identified during petrographic study. The sandstone are categorized as arkose and lithic arkose. Principal diagenetic events which have resulted in changing the primary characters of the sandstones are compaction, cementation, dissolution, and mineral replacement. The observed diagenetic processes can be grouped into early, burial, and late diagenesis. Chlorite is the dominant diagenetic constituent that occurs as rims, coatings, and replacing grains. The early phase of coating of authigenic chlorite has preserved the primary porosity. The recrystallization of chlorite into chamosite has massively reduced the original pore space because of its bridging structure. The current study reveals that diagenetic processes have altered the original rock properties and reservoir characteristics of the Lower Goru sandstone. These preliminary outcomes of this study have great potential to improve the understanding of diagenetic process and their impact on reservoir properties of the Lower Goru sandstone in the Lower Indus Basin and adjoining areas.

When Do Psychopathic Traits Affect Cooperative Behavior?: An Iterated Prisoner's Dilemma Experimental Study

2020 ◽  
Author(s):  
M Testori ◽  
M Kempf ◽  
RB Hoyle ◽  
Hedwig Eisenbarth
Keyword(s):  
Prisoner's Dilemma ◽  
Cooperative Behavior ◽  
Prisoner’S Dilemma ◽  
Selection Procedure ◽  
Psychopathic Traits ◽  
Strong Impact ◽  
Iterated Prisoner's Dilemma ◽  
Human Decision ◽  
The Impact ◽  
Iterated Prisoner’S Dilemma

© 2019 Hogrefe Publishing. Personality traits have been long recognized to have a strong impact on human decision-making. In this study, a sample of 314 participants took part in an online game to investigate the impact of psychopathic traits on cooperative behavior in an iterated Prisoner's dilemma game. We found that disinhibition decreased the maintenance of cooperation in successive plays, but had no effect on moving toward cooperation after a previous defection or on the overall level of cooperation over rounds. Furthermore, our results underline the crucial importance of a good model selection procedure, showing how a poor choice of statistical model can provide misleading results.

The Impact of Economic Crisis on Tourism Industry: A Bangladesh Perspective

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Md. Ziaul Haque
Keyword(s):  
Economic Crisis ◽  
Tourism Industry ◽  
Political Crisis ◽  
Strong Impact ◽  
Negative Consequences ◽  
Policy Makers ◽  
Tourism Product ◽  
International Tourist ◽  
Sustained Recovery ◽  
The Impact

The tourism sector is experiencing numerous challenges as a result of the global economic crisis. After a significant contraction in 2009, tourism rebounded strongly  in  2010  and  in  2011  the  international  tourist  arrivals  and  receipts  are projected to increase substantially. The Tourism industry is expected to show a sustained recovery in 2012. The crisis has particularly strong impact and slightly negative consequences in Bangladesh. The country is undergoing a political crisis, as well, and it seems that the forthcoming elections may be the only solution for the restoration of stability and social peace.  In addition, tourism can be the driving force behind Bangladesh economic recovery. However, for its achievement the country’s policy makers should take several measures towards restructuring and improving the sector. These measures include: enhancement of alternative forms of tourism; environmental protection; creation of quality infrastructure; and boost of competitiveness through a tourism product that offers value for money

The Impact Of Economic Crisis On Tourism Industry: A Bangladesh Perspective

2015 ◽  
Vol 1 (1) ◽  
pp. 15
Author(s):  
Md. Ziaul Haque
Keyword(s):  
Economic Crisis ◽  
Tourism Industry ◽  
Political Crisis ◽  
Strong Impact ◽  
Negative Consequences ◽  
Policy Makers ◽  
Tourism Product ◽  
International Tourist ◽  
Sustained Recovery ◽  
The Impact

The tourism sector is experiencing numerous challenges as a result of the global economic crisis. After a significant contraction in 2009, tourism rebounded strongly  in  2010  and  in  2011  the  international  tourist  arrivals  and  receipts  are projected to increase substantially. The Tourism industry is expected to show a sustained recovery in 2012. The crisis has particularly strong impact and slightly negative consequences in Bangladesh. The country is undergoing a political crisis, as well, and it seems that the forthcoming elections may be the only solution for the restoration of stability and social peace.  In addition, tourism can be the driving force behind Bangladesh economic recovery. However, for its achievement the country’s policy makers should take several measures towards restructuring and improving the sector. These measures include: enhancement of alternative forms of tourism; environmental protection; creation of quality infrastructure; and boost of competitiveness through a tourism product that offers value for money

Cost of Dementia and Its Correlation With Dependence

2016 ◽  
Vol 28 (8) ◽  
pp. 1448-1464 ◽  
Author(s):  
Örjan Åkerborg ◽  
Andrea Lang ◽  
Anders Wimo ◽  
Anders Sköldunger ◽  
Laura Fratiglioni ◽  
...  
Keyword(s):  
Cognitive Ability ◽  
Resource Utilization ◽  
Annual Cost ◽  
Neuropsychiatric Symptoms ◽  
Dementia Care ◽  
Cost Of Care ◽  
Path Model ◽  
National Study ◽  
Strong Impact ◽  
The Impact

Objective: To estimate the cost of dementia care and its relation to dependence. Method: Disease severity and health care resource utilization was retrieved from the Swedish National Study on Aging and Care. Informal care was assessed with the Resource Utilization in Dementia instrument. A path model investigates the relationship between annual cost of care and dependence, cognitive ability, functioning, neuropsychiatric symptoms, and comorbidities. Results: Average annual cost among patients diagnosed with dementia was €43,259, primarily incurred by accommodation. Resource use, that is, institutional care, community care, and accommodation, and corresponding costs increased significantly by increasing dependency. Path analysis showed that cognitive ability, functioning, and neuropsychiatric symptoms were significantly correlated with dependence, which in turn had a strong impact on annual cost. Discussion: This study confirms that cost of dementia care increases with dependence and that the impact of other disease indicators is mainly mediated by dependence.

scholarly journals The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials

2021 ◽  
Vol 11 (2) ◽  
pp. 700
Author(s):  
Irene A. Kanellopoulou ◽  
Ioannis A. Kartsonakis ◽  
Costas A. Charitidis
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Hybrid Structure ◽  
The Self ◽  
Self Healing ◽  
Cementitious Composite ◽  
Superabsorbent Polymers ◽  
Porosity Reduction ◽  
Environment Control ◽  
The Impact

Cementitious structures have prevailed worldwide and are expected to exhibit further growth in the future. Nevertheless, cement cracking is an issue that needs to be addressed in order to enhance structure durability and sustainability especially when exposed to aggressive environments. The purpose of this work was to examine the impact of the Superabsorbent Polymers (SAPs) incorporation into cementitious composite materials (mortars) with respect to their structure (hybrid structure consisting of organic core—inorganic shell) and evaluate the microstructure and self-healing properties of the obtained mortars. The applied SAPs were tailored to maintain their functionality in the cementitious environment. Control and mortar/SAPs specimens with two different SAPs concentrations (1 and 2% bwoc) were molded and their mechanical properties were determined according to EN 196-1, while their microstructure and self-healing behavior were evaluated via microCT. Compressive strength, a key property for mortars, which often degrades with SAPs incorporation, in this work, practically remained intact for all specimens. This is coherent with the porosity reduction and the narrower range of pore size distribution for the mortar/SAPs specimens as determined via microCT. Moreover, the self-healing behavior of mortar-SAPs specimens was enhanced up to 60% compared to control specimens. Conclusively, the overall SAPs functionality in cementitious-based materials was optimized.

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