Amplitude Variation with Offset Responses Modeling Study of Walkaway Vertical Seismic Profile Data at CO2 Geological Storage Site, Ketzin, Germany     

YANG Can  Sayed Hesammoddin KAZEMEINI  FAN Wenfang  Christopher JUHLIN  LIU Dameng 《《地质学报》英文版》2011,85(5):1118-1126

An important component of any CO2 sequestration project is seismic monitoring for tracking changes in subsurface physical properties, such as velocity and density. Different reservoirs have different amplitude variation with offset (AVO) responses, which can define underground conditions. In the present paper we investigate walkaway vertical seismic profile (VSP) AVO response to CO2 injection at the Ketzin site, the first European onshore CO2 sequestration pilot study dealing with research on geological storage of CO2. First, we performed rock physics analysis to evaluate the effect of injected CO2 on seismic velocity using the Biot-Gassmann equation. On the basis of this model, the seismic response for different CO2 injection saturation was studied using ray tracing modeling. We then created synthetic walkaway VSP data, which we then processed. In contrast, synthetic seismic traces were created from borehole data. Finally, we found that the amplitude of CO2 injected sand layer with different gas saturations were increased with the offset when compared with the original brine target layer. This is the typical class III AVO anomaly for gas sand layer. The AVO responses matched the synthetic seismic traces very well. Therefore, walkaway VSP AVO response can monitor CO2 distribution in the Ketzin area.  相似文献   

Subsurface structural trends of the offshore Nile Delta area, Egypt: evidences from gravity and magnetic data     

El Sayed Ibrahim Selim 《Environmental Earth Sciences》2013,68(4):1015-1032

Subsurface structural trends and tectonics affecting the offshore Nile Delta area, Egypt, have been studied through the interpretations of gravity and magnetic data. Reduced to the pole, regional–residual separation, Tilt derivative and Euler deconvolution techniques are applied for the processing and interpretations of the magnetic and gravity data. The average depth of the sedimentary cover, estimated from the two-dimensional power spectrum technique ranges between 8 km and 13 km. The interpretation of the gravity and magnetic data indicates that the study area is affected by many subsurface structural trends. The NW–SE is the major trend related to El-Temsah and Misfaq-Bardwil trend. The NE–SW direction is the second dominant trend, related to the Rosetta trend. Other trends defined through the interpretation of gravity and magnetic data include: the N–S direction, related to the Baltim fault trend, the E–W direction, related to the Neogene hinge line and the NNE–SSW related to the Gulf of Aqaba. Accessory trends include the ENE–WSW, WNW–ESE and finally the NNW–SSW.  相似文献   

Organisation hydrochimique,biologique et sédimentologique d’un lac intracontinental à peuplements lagunaires : la Birket Karoun (Fayoum,Egypte)     

Jean-Pierre Perthuisot  Olivier Guelorget  Ahmed Wahid et Sayed Ibrahim  Jean-Pierre Margerel  André Maurin  Maryvonne Piron-Frenet 《Geodinamica Acta》2013,26(2):73-89

Résumé

La Birket Karoun a été étudiée d’un point de vue biogéologique sur une période de 12 mois. Les données ainsi obtenues, ajoutées à celles de la littérature disponible, permettent de présenter les caractéristiques biogéologiques essentielles de ce bassin original.

Le lac n’est alimenté actuellement que par des eaux continentales issues du système nilotique ce qui entraîne des propriétés hydrochimiques assez différentes des corps d’eau paraliques influencés par la mer. Cependant, les caractéristiques hydrologiques, biologiques et sédimen-taires de la Birket Karoun la classent parmi les écosystèmes de type lagunaire. Il est même possible d’y reconnaître une organisation biogéologique zonale très semblable à celle des lagunes, la partie la plus « marine » (ou la moins confinée) se situant à l’opposé de la zone des apports d’eau douce. Une connexion entre le lac et la mer, actuelle ou passée, étant à peu près exclues, il faut admettre que les eaux continentales concentrées peuvent présenter, dans certains cas, des caractéristiques chimiques et biochimiques presque marines vis-à-vis des êtres vivants.

Dans cette optique, la Birket Karoun apparaît comme un modèle actuel susceptible de fournir une alternative à l’hypothèse d’une « Mer Saharienne » pour rendre compte de l’existence des lacs sahariens pleistocènes à faunes fossiles lagunaires.  相似文献   

Optimization of sulfur adsorption over Ag-zeolite nanoadsorbent by experimental design method     

G. Bakhtiari  M. Abdouss  M. Bazmi  S. J. Royaee 《International Journal of Environmental Science and Technology》2016,13(3):803-812

Environmental protection has mentioned the need to cut out all of fuels sulfur compounds. One of the most important processes that affect sulfur removal in atmospheric condition is the interaction of liquid fuels with solid sulfur removal adsorbents such as zeolites. To investigate the nano-AgX-zeolite efficiency for the sulfur adsorption process, a set of experimental tests was arranged and conducted by Box–Behnken design software, in an adsorption laboratory setup. The selected variables comprised metal percent, adsorption temperature and calcination temperature. The parameter levels were 0.5–10 %, 30–120 and 200–500 °C, respectively. The experiment results were used to find the statistical model. The results demonstrate that the sulfur concentration level is 48.36 ppm in the last product at 83 °C for adsorption temperature, 5.53 % for metal percent and 436 °C for calcination temperature in constant pH and constant process time.  相似文献   

Active tectonic trends and crustal modeling of the eastern Mediterranean Sea deduced from geophysical data     

El Sayed Selim  Essam Abouad  Sayed S. R. Moustafa  Nassir S. Al-Arifi 《Environmental Earth Sciences》2016,75(12):1036

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Integration of Remote Sensing & GIS to Manage the Sustainable Development in the Nile Valley Desert Fringes of Assiut-Sohag Governorates,Upper Egypt     

Mostafa kamel  El Sayed M. Abu El Ella 《Journal of the Indian Society of Remote Sensing》2016,44(5):759-774

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Arsenic contamination of ground and pond water and water purification system using pond water in Bangladesh   总被引：1，自引：0，他引：1  

H. Yokota  K. Tanabe  M. Sezaki  Y. Akiyoshi  T. Miyata  K. Kawahara  S. Tsushima  H. Hironaka  H. Takafuji  M. Rahman  Sk. A. Ahmad  M. H. S. U. Sayed  M. H. Faruquee 《Engineering Geology》2001,60(1-4):323-331

This paper, firstly, shows the distribution of arsenic-contaminated groundwater in Samta village. This village, which is in Jessore district in Bangladesh, was chosen as a model village for investigating the mechanism of groundwater contamination. 90% of the tube wells in this village had arsenic concentrations above the Bangladesh standard of 0.05 mg/l. Tube wells with arsenic concentrations of over 0.50 mg/l were distributed in the southern part of the village with a belt-like shape from east to west. Secondly, groundwater distribution is discussed with respect to its flow and the high arsenic zone (As≥0.50 mg/l) agrees well with the drifting zone of the groundwater. Furthermore, arsenic-free water supply systems suitable for a small area in the village have been developed. A pond sand filter (PSF) system which purifies pond water is discussed in this paper. Prior to the construction of the PSF, the water quality in ponds was examined for arsenic levels. The inflow of drainage from the tube wells was found to be the major cause of arsenic contamination of pond water. The PSF installed in Samta is working very well and produces a good quality of treated water.  相似文献   

Current stabilizer for the magnetic field of a mass spectrograph     

Sayed B. El-Kholy 《Pure and Applied Geophysics》1965,61(1):139-148

Summary A new automatic current stabilizer is constructed, which can be used for a magnetic field of a mass spectrograph. A stability of the order of 10^–6 is attained for relatively long intervals. The dependence of the magnetic field constancy on the different parameters of the stabilizer is investigated by methods of servomechanism.  相似文献   

Velocity and attenuation of compressional waves in nearly saturated soils   总被引：1，自引：0，他引：1  

J. P. Bardet  H. Sayed 《Soil Dynamics and Earthquake Engineering》1993,12(7)

Based on the two-phase theory of Biot, we present exact and approximate expressions for the velocity and attenuation of compressional waves within nearly saturated poroelastic media. We use the approximate solutions to model the low-frequency compressional waves within nearly saturated soils. The model accounts for the effective stress, degree of saturation, and void ratio, and is capable of describing experimental results on Ottawa sand. The three-phase theory of Vardoulakis and Beskos and the two-phase theory of Biot similarly describe the velocity and attenuation of compressional waves in most soils. However, the former theory breaks down for nearly saturated gravels and dense sands.  相似文献   

Estimation of frequency dependent coda wave attenuation structure at the vicinity of Cairo Metropolitan Area   总被引：1，自引：0，他引：1  

Salah El-Hadidy  M. E. Mohamed Adel  Ahmed Deif  Ahmed Sayed Abu El-Ata  S. R. Moustafa Sayed 《Acta Geophysica》2006,54(2):177-186

Estimation of seismic wave attenuation in the shallow crust in terms of coda wave Q structure previously investigated in the vicinity of Cairo Metropolitan Area was improved using seismograms of local earthquakes recorded by the Egyptian National Seismic Network. The seismic wave attenuation was measured from the time decay of coda wave amplitudes on narrow bandpass filtered seismograms based on the single scattering theory. The frequency bands of interest are from 1.5 to 18 Hz. In general, the values obtained for various events recorded at El-Fayoum and Wadi Hagul stations are very similar for all frequency bands. A regional attenuation law Q _c = 85.66 f ^0.79 was obtained.  相似文献