scholarly journals The key factors controlling reservoir quality of the Middle CambrianDeimena Group sandstone in West Lithuania

2002 ◽  
Vol 49 ◽  
pp. 25-39
Author(s):  
Linas Kilda ◽  
Henrik Friis
Keyword(s):  
Early Stage ◽  
Clay Fraction ◽  
Oil Fields ◽  
Reservoir Quality ◽  
Key Factors ◽  
Reservoir Properties ◽  
Carbonate Cement ◽  
Commercially Important ◽  
Early Carbonate

Sandstones of the Middle Cambrian Deimena Group are commercially important as they make up the largest part of the hydrocarbon-bearing reservoir in 15 oil fields discovered in West Lithuania. However, the sandstones are characterised by a very complicated spatial distribution of reservoir quality. In order to better understand the distribution of reservoir properties and their controlling parameters, eighty-two sandstone samples from twenty-one boreholes were studied by means of thin section description, scanning electron microscopy, using backscattered and cathodoluminescence modes and clay fraction analyses. Generally, the sandstones are strongly cemented by quartz, resulting in almost total destruction of porosity but porous domains with preserved early stage quartz cement occur in a complex pattern. The close location of the early and late stage overgrowth types indicates that some sandstone parts were preserved from intense authigenic quartz precipitation. We believe that early carbonate cement was such an inhibitor. Detrital quartz grains in carbonate cemented domains are mostly free of authigenic quartz and as a rule show weakly compacted fabric as compared to the quartz cemented parts. Moreover, large secondary pores are located close to the carbonate cemented domains and indicate that some carbonate cement eventually dissolved. Apparently, the best reservoir properties within the generally strongly quartz cemented Deimena Groupsandstones are found in domains where dissolution of the early carbonate cement took place.

scholarly journals The Evaluation of Reservoir Quality of Mishrif Formation in South and North Domes of Buzurgan Oil Field

2019 ◽  
Vol 9 (4) ◽  
pp. 89-106
Author(s):  
Ali Duair Jaafar ◽  
Dr. Medhat E. Nasser
Keyword(s):  
Physical Properties ◽  
Water Saturation ◽  
Oil Field ◽  
Reservoir Quality ◽  
Petrophysical Properties ◽  
The South ◽  
Reservoir Properties ◽  
Formation Evaluation ◽  
The North

Buzurgan field in the most cases regards important Iraqi oilfield, and Mishrif Formation is the main producing reservoir in this field, the necessary of so modern geophysical studies is necessity for description and interpret the petrophysical properties in this field. Formation evaluation has been carried out for Mishrif Formation of the Buzurgan oilfield depending on logs data. The available logs data were digitized by using Neuralog software. A computer processed interpretation (CPI) was done for each one of the studied wells from south and north domes using Techlog software V2015.3 in which the porosity, water saturation, and shale content were calculated. And they show that MB21 reservoir unit has the highest thickness, which ranges between (69) m in north dome to (83) m in south dome, and the highest porosity, between (0.06 - 0.16) in the north dome to (0.05 -0.21) in the south dome. The water saturation of this unit ranges between (25% -60%) in MB21 of north dome. It also appeared that the water saturation in the unit MB21 of south dome has the low value, which is between (16% - 25%). From correlation, the thickness of reservoir unit MB21 increases towards the south dome, while the thickness of the uppermost barrier of Mishrif Formation increases towards the north dome. The reservoir unit MB21 was divided into 9 layers due to its large thickness and its important petrophysical characterization. The distribution of petro physical properties (porosity and water saturation) has shown that MB 21 has good reservoir properties.

scholarly journals Impact of Diagenesis on the Reservoir Properties of the Cretaceous Sandstones in the Southern Bredasdorp Basin, Offshore South Africa

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 757
Author(s):  
Temitope Love Baiyegunhi ◽  
Kuiwu Liu ◽  
Oswald Gwavava ◽  
Christopher Baiyegunhi
Keyword(s):  
Oil And Gas ◽  
Gas Production ◽  
Reservoir Quality ◽  
Reservoir Properties ◽  
Oil And Gas Production ◽  
Thin Sections ◽  
Hydrocarbon Reservoir ◽  
Porosity And Permeability ◽  
The Impact

The Cretaceous sandstone in the Bredasdorp Basin is an essential potential hydrocarbon reservoir. In spite of its importance as a reservoir, the impact of diagenesis on the reservoir quality of the sandstones is almost unknown. This study is undertaken to investigate the impact of digenesis on reservoir quality as it pertains to oil and gas production in the basin. The diagenetic characterization of the reservoir is based on XRF, XRD SEM + EDX, and petrographic studies of 106 thin sections of sandstones from exploration wells E-AH1, E-AJ1, E-BA1, E-BB1 and E-D3 in the basin. The main diagenetic processes that have affected the reservoir quality of the sandstones are cementation by authigenic clay, carbonate and silica, growth of authigenic glauconite, dissolution of minerals and load compaction. Based on the framework grain–cement relationships, precipitation of the early calcite cement was either accompanied or followed up by the development of partial pore-lining and pore-filling clay cements, particularly illite. This clay acts as pore choking cement, which reduces porosity and permeability of the reservoir rocks. The scattered plots of porosity and permeability versus cement + clays show good inverse correlations, suggesting that the reservoir quality is mainly controlled by cementation and authigenic clays.

Innovative ability and entrepreneurial activity: two factors to enhance “quality of life”

2014 ◽  
Vol 29 (6) ◽  
pp. 469-475 ◽  
Author(s):  
Rajan Nataraajan ◽  
Madhukar G. Angur
Keyword(s):  
Quality Of Life ◽  
Knowledge Economy ◽  
Early Stage ◽  
Entrepreneurial Activity ◽  
Key Factors ◽  
Content Type ◽  
Two Factors ◽  
The Impact

Purpose – The purpose of this paper is to investigate the impact of aspects of knowledge economy covered by the Knowledge Economy Index [KEI] and aspects of entrepreneurial activity covered by the Global Entrepreneurship Index [GEI] on quality of life [QOL] in a country. Design/methodology/approach – Data pertaining to KEI, GEI and QOL for different countries were gathered and analyzed through correlation and regression analyses. Findings – The results of the analysis yielded two key findings: First, KEI and GEI have a significant effect on QOL. Second, the Innovation Index (a component of KEI) and the total early stage entrepreneurship (a component of GEI) emerge as key factors that improve QOL. Originality/value – The value of this research lies in the fact that it unearths the two factors in KEI and GEI that actually impact QOL. By establishing and reinforcing the salience of innovative ability and entrepreneurial activity, this research helps long-term planners of an economy to fine-tune their focus.

Diagnetic history and reservoir quality of a Brent Sand sequence

Clay Minerals ◽  
1984 ◽  
Vol 19 (3) ◽  
pp. 377-389 ◽  
Author(s):  
G. A. Blackbourn
Keyword(s):  
North Sea ◽  
Late Stage ◽  
Middle Jurassic ◽  
Reservoir Quality ◽  
Pore Filling ◽  
Mineral Phases ◽  
Carbonate Cementation ◽  
Early Carbonate ◽  
Northern North Sea

AbstractThe Etive Formation of the Middle Jurassic Brent Group in part of the Northern North Sea comprises dominantly clean, fine- to medium-grained sands, deposited as part of a barrier-bar complex. The overlying Ness Formation was deposited on supra- or intertidal fiats, and comprises silty channel sands with silts, muds and thin coals. The sands of both Formations are mainly quartz-rich, with up to 12% by volume of feldspar, and variable proportions of clayey matrix. Early carbonate cementation preceded a phase of quartz overgrowth, which continued during burial. Later dissolution of unstable grains, dominantly feldspars, was followed by precipitation of pore-filling kaolinite and minor late-stage mineral phases. Better permeability of the Ness sands (up to 500 mD) relative to the Etive (mostly <10 mD) is mainly due to the effects of diagenesis on different lithofacies. Silty sands escaped intense quartz cementation and were thus more affected by acid groundwaters which improved permeability.

scholarly journals Quality of Life among Bangladeshi Youth during the Early Stage of the COVID-19 Pandemic: A Single-site Survey

2021 ◽  
pp. 100157
Author(s):  
Somaresh Kumar Mondal ◽  
Abdul Gaffar Khan ◽  
Md. Mamun Ali ◽  
Mir Kaosar Ahamed ◽  
Kawsar Ahmed
Keyword(s):  
Quality Of Life ◽  
Early Stage ◽  
Single Site ◽  
Site Survey

scholarly journals Fast Multi-Focus Fusion Based on Deep Learning for Early-Stage Embryo Image Enhancement

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 863
Author(s):  
Vidas Raudonis ◽  
Agne Paulauskaite-Taraseviciene ◽  
Kristina Sutiene
Keyword(s):  
Deep Learning ◽  
Image Fusion ◽  
Early Stage ◽  
Image Data ◽  
Cell Detection ◽  
Processing Times ◽  
Fused Image ◽  
Stage Embryo ◽  
Early Stage Embryo

Background: Cell detection and counting is of essential importance in evaluating the quality of early-stage embryo. Full automation of this process remains a challenging task due to different cell size, shape, the presence of incomplete cell boundaries, partially or fully overlapping cells. Moreover, the algorithm to be developed should process a large number of image data of different quality in a reasonable amount of time. Methods: Multi-focus image fusion approach based on deep learning U-Net architecture is proposed in the paper, which allows reducing the amount of data up to 7 times without losing spectral information required for embryo enhancement in the microscopic image. Results: The experiment includes the visual and quantitative analysis by estimating the image similarity metrics and processing times, which is compared to the results achieved by two wellknown techniques—Inverse Laplacian Pyramid Transform and Enhanced Correlation Coefficient Maximization. Conclusion: Comparatively, the image fusion time is substantially improved for different image resolutions, whilst ensuring the high quality of the fused image.

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