Petroleum system analysis of the Khatatba Formation in the Shoushan Basin,north Western Desert,Egypt     

Mohamed Ragab Shalaby  Mohammed Hail Hakimi  Wan Hasiah Abdullah 《Arabian Journal of Geosciences》2014,7(10):4303-4320

The Middle Jurassic Khatatba Formation is an attractive petroleum exploration target in the Shoushan Basin, north Western Desert, Egypt. However, the Khatatba petroleum system with its essential elements and processes has not been assigned yet. This study throws the lights on the complete Khatatba petroleum system in the Shoushan Basin which has been evaluated and collectively named the Khatatba-Khatatba (!) petroleum system. To evaluate the remaining hydrocarbon potential of the Khatatba system, its essential elements were studied, in order to determine the timing of hydrocarbon generation, migration and accumulation. Systematic analysis of the petroleum system of the Khatatba Formation has identified that coaly shales and organic-rich shales are the most important source rocks. These sediments are characterised by high total organic matter content and have good to excellent hydrocarbon generative potential. Kerogen is predominantly types II–III with type III kerogen. The Khatatba source rocks are mature and, at the present time, are within the peak of the oil window with vitrinite reflectance values in the range of 0.81 to 1.08 % Ro. The remaining hydrocarbon potential is anticipated to exist mainly in stratigraphic traps in the Khatatba sandstones which are characterised by fine to coarse grain size, moderate to well sorted. It has good quality reservoir with relatively high porosity and permeability values ranging from 1 to 17 % and 0.05–1,000 mD, respectively. Modelling results indicated that hydrocarbon generation from the Khatatba source rocks began in the Late Cretaceous time and peak of hydrocarbon generation occurred during the end Tertiary time (Neogene). Hydrocarbon primarily migrated from the source rock via fractured pathways created by abnormally high pore pressures resulting from hydrocarbon generation. Hydrocarbon secondarily migrated from active Khatatba source rocks to traps side via vertical migration pathways through faults resulting from Tertiary tectonics during period from end Oligocene to Middle Miocene times.  相似文献   

Diagenesis in the Middle Jurassic Khatatba Formation sandstones in the Shoushan Basin,northern Western Desert,Egypt     

Mohamed R. Shalaby  Mohammed H. Hakimi  Wan Hasiah Abdullah 《Geological Journal》2014,49(3):239-255

The Middle Jurassic Khatatba Formation acts as a hydrocarbon reservoir in the subsurface in the Western Desert, Egypt. This study, which is based on core samples from two exploration boreholes, describes the lithological and diagenetic characteristics of the Khatatba Formation sandstones. The sandstones are fine‐ to coarse‐grained, moderately to well‐sorted quartz arenites, deposited in fluvial channels and in a shallow‐marine setting. Diagenetic components include mechanical and chemical compaction, cementation (calcite, clay minerals, quartz overgrowths, and a minor amount of pyrite), and dissolution of calcite cements and feldspar grains. The widespread occurrence of an early calcite cement suggests that the Khatatba sandstones lost a significant amount of primary porosity at an early stage of its diagenetic history. In addition to calcite, several different cements including kaolinite and syntaxial quartz overgrowth occur as pore‐filling and pore‐lining cements. Kaolinite (largely vermicular) fills pore spaces and causes reduction in the permeability of the reservoir. Based on framework grain–cement relationships, precipitation of the early calcite cement was either accompanied by or followed the development of part of the pore‐lining and pore‐filling cements. Secondary porosity development occurred due to partial to complete dissolution of early calcite cements and feldspar. Late kaolinite clay cement occurs due to dissolved feldspar and has an impact on the reservoir quality of the Khatatba sandstones. Open hydraulic fractures also generated significant secondary porosity in sandstone reservoirs, where both fractures and dissolution took place in multiple phases during late diagenetic stages. The diagenesis and sedimentary facies help control the reservoir quality of the Khatatba sandstones. Fluvial channel sandstones have the highest porosities and permeabilities, in part because of calcite cementation, which inhibited authigenic clays or was later dissolved, creating intergranular secondary porosity. Fluvial crevasse‐splay and marine sandstones have the lowest reservoir quality because of an abundance of depositional kaolinite matrix and pervasive, shallow‐burial calcite and quartz overgrowth cements, respectively. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Compressive and Tensile Behavior of Polymer Treated Sulfate Contaminated CL Soil   总被引：1，自引：1，他引：0  

Ahmed S. Mohammed  Cumaraswamy Vipulanandan 《Geotechnical and Geological Engineering》2014,32(1):71-83

In this study, the compressive and tensile behavior of polymer treated sulfate contaminated CL soil was investigated. Based on the information in the literature, a field soil was contaminated with up to 4 % (40,000 ppm) of calcium sulfate in this study. In addition to characterizing the behavior of sulfate contaminated CL soil, the effect of treating the soil with a polymer solution was investigated and the performance was compared to 6 % lime treated soil. In treating the soil, acrylamide polymer solution (15 g of polymer dissolved in 85 g of water) content was varied up to 15 % (by dry soil weight). Addition of 4 % calcium sulfate to the soil decreased the compressive and tensile strengths of the compacted soils by 22 and 33 % respectively with the formation of calcium silicate sulfate [ternesite Ca₅(SiO₄)₂SO₄)], magnesium silicate sulfate (Mg₅(SiO₄)₂SO₄) and calcium-magnesium silicate (merwinite Ca₃Mg(SiO₄)₂). With the polymer treatment the strength properties of sulfate contaminated CL soil was substantially improved. Polymer treated sulfate soils had higher compressive and tensile strengths and enhanced compressive stress–strain relationships compared to the lime treated soils. Also polymer treated soils gained strength more rapidly than lime treated soil. With 10 % of polymer solution treatment, the maximum unconfined compressive and splitting tensile strengths for 4 % of calcium sulfate soil were 625 kPa (91 psi) and 131 kPa (19 psi) respectively in 1 day of curing. Similar improvement in the compressive modulus was observed with polymer treated sulfate contaminated CL soil. The variation of the compacted compressive strength and tensile strength with calcium sulfate concentrations for the treated soils were quantified and the parameters were related to calcium sulfate content in the soil and polymer content. Compressive stress–strain relationships of the sulfate soil, with and without lime and polymer treatment, have been quantified using two nonlinear constitutive models. The constitutive model parameters were sensitive to the calcium sulfate content and the type of treatment.  相似文献   

Mycological evidence of coprophagy from the feces of an Alaskan Late Glacial mammoth     

Bas van Geel  R. Dale Guthrie  Jens G. Altmann  Peter Broekens  Ian D. Bull  Fiona L. Gill  Boris Jansen  Aline M. Nieman  Barbara Gravendeel 《Quaternary Science Reviews》2011,30(17-18):2289-2303

Dung from a mammoth was preserved under frozen conditions in Alaska. The mammoth lived during the early part of the Late Glacial interstadial (ca 12,300 BP). Microfossils, macroremains and ancient DNA from the dung were studied and the chemical composition was determined to reconstruct both the paleoenvironment and paleobiology of this mammoth. Pollen spectra are dominated by Poaceae, Artemisia and other light-demanding taxa, indicating an open, treeless landscape (‘mammoth steppe’). Fruits and seeds support this conclusion. The dung consists mainly of cyperaceous stems and leaves, with a minor component of vegetative remains of Poaceae. Analyses of fragments of the plastid rbcL gene and trnL intron and nrITS1 region, amplified from DNA extracted from the dung, supplemented the microscopic identifications. Many fruit bodies with ascospores of the coprophilous fungus Podospora conica were found inside the dung ball, indicating that the mammoth had eaten dung. The absence of bile acids points to mammoth dung. This is the second time that evidence for coprophagy of mammoths has been derived from the presence of fruit bodies of coprophilous fungi in frozen dung. Coprophagy might well have been a common habit of mammoths. Therefore, we strongly recommend that particular attention should be given to fungal remains in future fossil dung studies.  相似文献   

The motion of artificial satellites in the set of Eulerian redundant parameters     

Mohammed Adel Sharaf  Mervat El-Sayed Awad  Samiha Al-Sayed Abdullah Najmuldeen 《Earth, Moon, and Planets》1991,55(1):21-44

In this paper, the connections between orbit dynamics and rigid body dynamics are established throughout the Eulerian redundant parameters, the perturbation equations for any conic motion of artificial satellites are derived in terms of these parameters. A general recursive and stable computational algorithm is also established for the initial-value problem of the Eulerian parameters for satellites prediction in the Earth's gravitational field with axial symmetry. Applications of the algorithm are considered for the two cases of short and long term predictions. For the short-term prediction, we consider the problem of the final state prediction of some typical ballistic missiles in the geopotential model with zonal harmonic terms up to J ₃₆, while for the long-term prediction, we consider the perturbed J ₂ motion of Explorer 28 over 100 revolutions.  相似文献   

Theorizing and Researching Intersectionality: A Challenge for Feminist Geography*   总被引：1，自引：0，他引：1  

Gill Valentine 《The Professional geographer》2007,59(1):10-21

This article focuses on the concept of intersectionality, which is being used within the wider social sciences by feminists to theorize the relationship between different social categories: gender, race, sexuality, and so forth. Although research within the field of feminist geography has explored particular interconnections such as those between gender and race, the theoretical concept of intersectionality as debated in the wider social sciences has not been addressed. This article attempts to respond to that omission. It begins by tracing the emergence of debates about the interconnections between gender and other identities. It goes on to reflect on attempts to map geometries of oppressions. The emphasis then moves from theorizing intersectionality to questioning how it can be researched in practice by presenting a case study to illustrate intersectionality as lived experience. The conclusion demonstrates the contribution that feminist geography can make to advance the theorization of intersectionality through its appreciation of the significance of space in processes of subject formation. It calls for feminist geography to pay more attention to questions of power and social inequalities.  相似文献   

A geochemical survey of thermal springs in western part ofRepublic of Yemen and their geothermometric characteristics     

HazaeaMohammed HUKe 《东北亚地学研究》2004,7(1):58-63

The high-mineral contents of some thermal waters are believed to have medicinal properties. Numerous spas and bathhouses might be built at these hot springs to take advantage of theses supposed healing properties such as skin diseases, rheumatism and so on. This paper is to find thermal reservoir and to classify the kinds of water. The majority of thermal springs are found discharging from igneous centers of Tertiary and Quaternary volcanic fields of the western Yemen (research area). Structurally these volcanisms are connected to N-NW faults that are parallel to the main Red Sea trend. Temperature and pH values of the thermal spring range 37℃-96℃, and 6.3-8.7 respectively. The Yemen/thermal waters indicate high variability in composition since they are ofNa (K) -CI, Na=HCO3 and Ca (Mg) =SO4 types, whereas the surficial waters have the typical worldwide Ca (Mg) -HCO3 composition. Different liquid phase geothermometers,such as SiO2, K^2/Mg and Na/K. Estimated reservoir temperatures ranging 70℃-140℃ perform equilibrium temperature evaluation of the thermal reservoirs.  相似文献   

The evolution of substructure – II. Linking dynamics to environment     

Stuart P. D. Gill  Alexander Knebe  Brad K. Gibson  Michael A. Dopita 《Monthly notices of the Royal Astronomical Society》2004,351(2):410-422

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Evaluation of the Flow Measurement Performance of Compound Sharp-Crested Over-Fall Weirs and Optimized Discharge Measurement in Data Scarce Areas     

Kassaye  Aklilu Alemayehu  Mohammed  Abdella Kemal  Angello  Zelalem Abera 《Water Resources》2022,49(3):402-412

Water Resources - The hydraulic relationships of flow through the weir of different common shapes were investigated in this study. The hydraulic performances of weirs were carried out...  相似文献   

Extraction and analysis of geological lineaments by combining ASTER-GDEM and Landsat 8 image data in the central high atlas of Morocco     

Abdelouhed  Farah  Ahmed  Algouti  Abdellah  Algouti  Mohammed  Ifkirne  Zouhair  Ourhzif 《Natural Hazards》2022,111(2):1907-1929

Natural Hazards - The present work focuses on using remote sensing techniques and geographical information system (GIS) to automatically extract lineaments in the southeast of Morocco, which is one...  相似文献