Spatial variation in porosity and permeability of the Rupel Clay Member in the Netherlands

AbstractThe spatial distribution of porosity and permeability of the Rupel Clay Member is of key importance to evaluate the spatial variation of its sealing capacity and groundwater flow condition. There are only a limited number of measured porosity and permeability data of the Rupel Clay Member in the onshore Netherlands and these data are restricted to shallow depths in the order of tens of metres below surface. Grain sizes measured by laser diffraction and SediGraph® in samples of the Rupel Clay Member taken from boreholes spread across the country were used to generate new porosity and permeability data for the Rupel Clay Member located at greater burial depth. Effective stress and clay content are important parameters in the applied grain-size based calculations of porosity and permeability.The calculation method was first tested on measured data of the Belgian Boom Clay. The test results showed good agreement between calculated permeability and measured hydraulic conductivity for depths exceeding 200m.The spatial variation in lithology, heterogeneity and also burial depth of the Rupel Clay Member in the Netherlands are apparent in the variation of the calculated permeability. The samples from the north of the country consist almost entirely of muds and as a consequence show little lithology-related variation in permeability. The vertical variation in permeability in the more heterogeneous Rupel Clay Member in the southern and east-southeastern part of the country can reach several orders of magnitude due to increased permeability of the coarser-grained layers.

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Reservoir quality and its controlling diagenetic factors in the Bentiu Formation, Northeastern Muglad Basin, Sudan

Scientific Reports ◽

10.1038/s41598-021-97994-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yousif M. Makeen ◽

Xuanlong Shan ◽

Mutari Lawal ◽

Habeeb A. Ayinla ◽

Siyuan Su ◽

...

Keyword(s):

Clay Content ◽

Petroleum Exploration ◽

Reservoir Quality ◽

Burial Depth ◽

Petroleum Reservoir ◽

Fine Grained ◽

Porosity And Permeability ◽

Negative Role ◽

Crevasse Splay ◽

Channel Deposits

AbstractThe Abu Gabra and Bentiu formations are widely distributed within the interior Muglad Basin. Recently, much attention has been paid to study, evaluate and characterize the Abu Gabra Formation as a proven reservoir in Muglad Basin. However, few studies have been documented on the Bentiu Formation which is the main oil/gas reservoir within the basin. Therefore, 33 core samples of the Great Moga and Keyi oilfields (NE Muglad Basin) were selected to characterize the Bentiu Formation reservoir using sedimentological and petrophysical analyses. The aim of the study is to de-risk exploration activities and improve success rate. Compositional and textural analyses revealed two main facies groups: coarse to-medium grained sandstone (braided channel deposits) and fine grained sandstone (floodplain and crevasse splay channel deposits). The coarse to-medium grained sandstone has porosity and permeability values within the range of 19.6% to 32.0% and 1825.6 mD to 8358.0 mD respectively. On the other hand, the fine grained clay-rich facies displays poor reservoir quality as indicated by porosity and permeability ranging from 1.0 to 6.0% and 2.5 to 10.0 mD respectively. A number of varied processes were identified controlling the reservoir quality of the studies samples. Porosity and permeability were enhanced by the dissolution of feldspars and micas, while presence of detrital clays, kaolinite precipitation, iron oxides precipitation, siderite, quartz overgrowths and pyrite cement played negative role on the reservoir quality. Intensity of the observed quartz overgrowth increases with burial depth. At great depths, a variability in grain contact types are recorded suggesting conditions of moderate to-high compactions. Furthermore, scanning electron microscopy revealed presence of micropores which have the tendency of affecting the fluid flow properties in the Bentiu Formation sandstone. These evidences indicate that the Bentiu Formation petroleum reservoir quality is primarily inhibited by grain size, total clay content, compaction and cementation. Thus, special attention should be paid to these inhibiting factors to reduce risk in petroleum exploration within the area.

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Rhineland on the Way to its Thousandth Anniversary or Water-Administration in the Next 100–200 Years

Water Science & Technology ◽

10.2166/wst.1991.0400 ◽

1991 ◽

Vol 23 (1-3) ◽

pp. 49-55

Author(s):

E. H. baron van Tuyll van Serooskerken

Keyword(s):

The Netherlands ◽

Late Summer ◽

Water Shortage ◽

Land Utilization ◽

Water Control ◽

Coastal Defence ◽

The North ◽

Policies And Measures ◽

Water Provision ◽

Water Administration

An inventory is made of the effects of sea level rise and expected climatic change on the level of the district water authorities in the Netherlands and especially the “hoogheemraadschap” of Rhineland in the next 100-200 years. Special attention is paid to the effects on land utilization, coastal defence and water control. The first is hard to describe by lack of research, the second can already be determined in terms of cost; the third can be described in its effects on brackishness and water provision with indication of policies and measures to be taken. Preliminary conclusions are that larger efforts on coastal defence - even with present techniques - will be a realistic answer in terms of cost. The foreseen increase of brackishness in area and salt concentration, will give a significant extra need for fresh water. High cost and even higher risks have to be expected with regard to measures to neutralize the effects of a water surplus in winter and a growing water shortage in (late) summer, while the cost will further grow. Because of the effect a larger area must be drained off and water has to be raised higher as the Netherlands will sink in relation to the North Sea.

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Palynological indications for Silurian – earliest Devonian age strata in the Netherlands

Netherlands Journal of Geosciences – Geologie en Mijnbouw ◽

10.1017/njg.2020.20 ◽

2021 ◽

Vol 100 ◽

Author(s):

Alexander J.P. Houben ◽

Geert-Jan Vis

Keyword(s):

The Netherlands ◽

Core Material ◽

Late Devonian ◽

Time Interval ◽

The South ◽

Early Devonian ◽

The North ◽

Depositional Settings ◽

Palynological Study ◽

Devonian Age

Abstract Knowledge of the stratigraphic development of pre-Carboniferous strata in the subsurface of the Netherlands is very limited, leaving the lithostratigraphic nomenclature for this time interval informal. In two wells from the southwestern Netherlands, Silurian strata have repeatedly been reported, suggesting that these are the oldest ever recovered in the Netherlands. The hypothesised presence of Silurian-aged strata has not been tested by biostratigraphic analysis. A similar lack of biostratigraphic control applies to the overlying Devonian succession. We present the results of a palynological study of core material from wells KTG-01 and S05-01. Relatively low-diversity and poorly preserved miospore associations were recorded. These, nonetheless, provide new insights into the regional stratigraphic development of the pre-Carboniferous of the SW Netherlands. The lower two cores from well KTG-01 are of a late Silurian (Ludlow–Pridoli Epoch) to earliest Devonian (Lochkovian) age, confirming that these are the oldest sedimentary strata ever recovered in the Netherlands. The results from the upper cored section from the pre-Carboniferous succession in well KTG-01 and the cored sections from the pre-Carboniferous succession in well S05-01 are more ambiguous. This inferred Devonian succession is, in the current informal lithostratigraphy of the Netherlands, assigned to the Banjaard group and its subordinate Bollen Claystone formation, of presumed Frasnian (i.e. early Late Devonian) age. Age-indicative Middle to Late Devonian palynomorphs were, however, not recorded, and the overall character of the poorly preserved palynological associations in wells KTG-01 and S05-01 may also suggest an Early Devonian age. In terms of lithofacies, however, the cores in well S05-01 can be correlated to the upper Frasnian – lower Famennian Falisolle Formation in the Campine Basin in Belgium. Hence, it remains plausible that an unconformity separates Silurian to Lower Devonian strata from Upper Devonian (Frasnian–Famennian) strata in the SW Netherlands. In general, the abundance of miospore associations points to the presence of a vegetated hinterland and a relatively proximal yet relatively deep marine setting during late Silurian and Early Devonian times. This differs markedly from the open marine depositional settings reported from the Brabant Massif area to the south in present-day Belgium, suggesting a sediment source to the north. The episodic presence of reworked (marine) acritarchs of Ordovician age suggests the influx of sedimentary material from uplifted elements on the present-day Brabant Massif to the south, possibly in relation to the activation of a Brabant Arch system.

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Does natural selection favour taller stature among the tallest people on earth?

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.0211 ◽

2015 ◽

Vol 282 (1806) ◽

pp. 20150211 ◽

Cited By ~ 30

Author(s):

Gert Stulp ◽

Louise Barrett ◽

Felix C. Tropf ◽

Melinda Mills

Keyword(s):

Natural Selection ◽

Reproductive Success ◽

The Netherlands ◽

Child Survival ◽

Average Height ◽

Tall Stature ◽

Age At First Birth ◽

Number Of Children ◽

The North ◽

Rate Of Increase

The Dutch are the tallest people on earth. Over the last 200 years, they have grown 20 cm in height: a rapid rate of increase that points to environmental causes. This secular trend in height is echoed across all Western populations, but came to an end, or at least levelled off, much earlier than in The Netherlands. One possibility, then, is that natural selection acted congruently with these environmentally induced changes to further promote tall stature among the people of the lowlands. Using data from the LifeLines study, which follows a large sample of the population of the north of The Netherlands ( n = 94 516), we examined how height was related to measures of reproductive success (as a proxy for fitness). Across three decades (1935–1967), height was consistently related to reproductive output (number of children born and number of surviving children), favouring taller men and average height women. This was despite a later age at first birth for taller individuals. Furthermore, even in this low-mortality population, taller women experienced higher child survival, which contributed positively to their increased reproductive success. Thus, natural selection in addition to good environmental conditions may help explain why the Dutch are so tall.

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Seasonal and spatial variation of phytoplankton assemblages, biomass and cell size from spring to summer across the north-eastern New Zealand continental shelf

Journal of Plankton Research ◽

10.1093/plankt/25.7.737 ◽

2003 ◽

Vol 25 (7) ◽

pp. 737-758 ◽

Cited By ~ 58

Author(s):

F. H. Chang

Keyword(s):

New Zealand ◽

Continental Shelf ◽

Spatial Variation ◽

Cell Size ◽

Phytoplankton Assemblages ◽

The North ◽

North Eastern

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Tight Jurassic Carbonate Reservoir Characterization and Fluid Typing Identification by Integrating Magnetic Resonance, Elemental Spectroscopy and Micro-Resistivity Image Data in Umm Ross Field, West Kuwait, Case Study

10.2118/207883-ms ◽

2021 ◽

Author(s):

Said Beshry Mohamed ◽

Sherif Ali ◽

Mahmoud Fawzy Fahmy ◽

Fawaz Al-Saqran

Keyword(s):

Magnetic Resonance ◽

Reservoir Characterization ◽

Clay Content ◽

Effective Porosity ◽

Carbonate Reservoir ◽

High Resistivity ◽

Permeability Index ◽

Rock Quality ◽

Porosity And Permeability ◽

Bulk Volume

Abstract The Middle Marrat reservoir of Jurassic age is a tight carbonate reservoir with vertical and horizontal heterogeneous properties. The variation in lithology, vertical and horizontal facies distribution lead to complicated reservoir characterization which lead to unexpected production behavior between wells in the same reservoir. Marrat reservoir characterization by conventional logging tools is a challenging task because of its low clay content and high-resistivity responses. The low clay content in Marrat reservoirs gives low gamma ray counts, which makes reservoir layer identification difficult. Additionally, high resistivity responses in the pay zones, coupled with the tight layering make production sweet spot identification challenging. To overcome these challenges, integration of data from advanced logging tools like Sidewall Magnetic Resonance (SMR), Geochemical Spectroscopy Tool (GST) and Electrical Borehole Image (EBI) supplied a definitive reservoir characterization and fluid typing of this Tight Jurassic Carbonate (Marrat formation). The Sidewall Magnetic resonance (SMR) tool multi wait time enabled T2 polarization to differentiate between moveable water and hydrocarbons. After acquisition, the standard deliverables were porosity, the effective porosity ratio, and the permeability index to evaluate the rock qualities. Porosity was divided into clay-bound water (CBW), bulk-volume irreducible (BVI) and bulk-volume moveable (BVM). Rock quality was interpreted and classified based on effective porosity and permeability index ratios. The ratio where a steeper gradient was interpreted as high flow zones, a gentle gradient as low flow zones, and a flat gradient was considered as tight baffle zones. SMR logging proved to be essential for the proper reservoir characterization and to support critical decisions on well completion design. Fundamental rock quality and permeability profile were supplied by SMR. Oil saturation was identified by applying 2D-NMR methods, T1/T2 vs. T2 and Diffusion vs. T2 maps in a challenging oil-based mud environment. The Electrical Borehole imaging (EBI) was used to identify fracture types and establish fracture density. Additionally, the impact of fractures to enhance porosity and permeability was possible. The Geochemical Spectroscopy Tool (GST) for the precise determination of formation chemistry, mineralogy, and lithology, as well as the identification of total organic carbon (TOC). The integration of the EBI, GST and SMR datasets provided sweet spots identification and perforation interval selection candidates, which the producer used to bring wells onto production.

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Interprofessional collaboration among care professionals in obstetrical care: are perceptions aligned?

BMJ Quality & Safety ◽

10.1136/bmjqs-2016-006401 ◽

2017 ◽

Vol 27 (4) ◽

pp. 279-286 ◽

Cited By ~ 9

Author(s):

Anita Romijn ◽

Pim W Teunissen ◽

Martine C de Bruijne ◽

Cordula Wagner ◽

Christianne J M de Groot

Keyword(s):

Primary Care ◽

The Netherlands ◽

Interprofessional Collaboration ◽

Cross Sectional Study ◽

Measurement Scale ◽

Cross Sectional ◽

Communication Accommodation ◽

Obstetrical Care ◽

The North ◽

Ensure Patient Safety

BackgroundIn an obstetrical team, obstetricians, midwives and nurses work together in a dynamic and complex care setting. Different professional cultures can be a barrier for effective interprofessional collaboration. Although the different professional cultures in obstetrical care are well known, little is understood about discrepancies in mutual perceptions of collaboration. Similar perceptions of collaboration are important to ensure patient safety. We aimed to understand how different care professionals in an obstetrical team assess interprofessional collaboration in order to gain insight into the extent to which their perceptions are aligned.MethodsThis cross-sectional study was performed in the north-western region of the Netherlands. Care professionals from five hospitals and surrounding primary-care midwifery practices were surveyed. The respondents consisted of four groups of care professionals: obstetricians (n=74), hospital-based midwives known as clinical midwives (n=42), nurses (n=154) and primary-care midwives (n=109). The overall response rate was 80.8%. We used the Interprofessional Collaboration Measurement Scale (IPCMS) to assess perceived interprofessional collaboration. The IPCMS distinguishes three subscales: communication, accommodation and isolation. Data were analysed using non-parametrical tests.ResultsOverall, ratings of interprofessional collaboration were good. Obstetricians rated their collaboration with clinical midwives, nurses and primary-care midwives more positively than these three groups rated the collaboration with obstetricians. Discrepancies in mutual perceptions were most apparent in the isolation subscale, which is about sharing opinions, discussing new practices and respecting each other.ConclusionWe found relevant discrepancies in mutual perceptions of collaboration in obstetrical care in the Netherlands. Obstetrical care is currently being reorganised to enable more integrated care, which will have consequences for interprofessional collaboration. The findings of this study indicate opportunities for improvement especially in terms of perceived isolation.

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