{"title":"Efficacy of Hummel (Modified Schlumberger) Arrays of Vertical Electrical Sounding in Groundwater Exploration: Case Study of Parts of Ibadan Metropolis, Southwestern Nigeria","authors":"M. Oladunjoye, S. Jekayinfa","doi":"10.1155/2015/612303","DOIUrl":"https://doi.org/10.1155/2015/612303","url":null,"abstract":"This research compared the interpretation results of the Vertical Electrical Sounding data acquired using the conventional Schlumberger and modified Schlumberger arrays with a view to assessing the effectiveness of the modified Schlumberger arrays of vertical electrical sounding as an alternative to the conventional Schlumberger array at sites with space constraint during groundwater exploration. A total of thirty-seven (37) sounding locations were occupied and one hundred (100) sounding data for both conventional Schlumberger and modified Schlumberger arrays were collected across different rock units within Ibadan metropolis, south-western Nigeria, with electrode spacing () ranging from 1 to 75 m. The field data were interpreted qualitatively by curve matching and computer iterative methods. Also, statistical analysis of subsurface units and the coefficient of correlation “” of the statistical plots of the field data shows the relationship between the different arrays. The raw data plot of the different arrays shows significant similarities while statistical analysis of the geo-electric parameters obtained from the different arrays across varied lithologic units show that strong relationships exist between the different field methods. The coefficient of correlation with values ranging from 0.7 to 0.99 implies that a good similarity exists between the different field methods employed in this study. Hence, modified Schlumberger arrays can be said to be a good alternative to the conventional Schlumberger array for groundwater exploration especially in urban settings where space constraint is a major challenge.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/612303","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65057187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"3D Geometric Modeling of the Abu Madi Reservoirs and Its Implication on the Gas Development in Baltim Area (Offshore Nile Delta, Egypt)","authors":"M. Abdel-Fattah, Ahmed Y. Tawfik","doi":"10.1155/2015/369143","DOIUrl":"https://doi.org/10.1155/2015/369143","url":null,"abstract":"3D geometric modeling has received renewed attention recently, in the context of visual scene understanding. The reservoir geometry of the Baltim fields is described by significant elements, such as thickness, depth maps, and fault planes, resulting from an interpretation based on seismic and well data. Uncertainties affect these elements throughout the entire interpretation process. They have some bearing on the geometric shape and subsequently on the gross reservoir volume (GRV) of the fields. This uncertainty on GRV also impacts volumes of hydrocarbons in place, reserves, and production profiles. Thus, the assessment of geometrical uncertainties is an essential first step in a field study for evaluation, development, and optimization purposes. Seismic data are best integrated with well and reservoir information. A 3D geometric model of the Late Messinian Abu Madi reservoirs in the time and depth domain is used to investigate the influence of the reservoir geometry on the gas entrapment. Important conceptual conclusions about the reservoir system behavior are obtained using this model. The results show that the reservoir shape influences the seismic response of the incised Abu Madi Paleovalley, making it necessary to account for 3D effects in order to obtain accurate results.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/369143","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64925146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Alatas, D. D. Prayuda, A. Syafiuddin, M. Parlindungan, Nurjaman O. Suhendra, H. Pawitan
{"title":"Simple Model for Simulating Characteristics of River Flow Velocity in Large Scale","authors":"H. Alatas, D. D. Prayuda, A. Syafiuddin, M. Parlindungan, Nurjaman O. Suhendra, H. Pawitan","doi":"10.1155/2015/520893","DOIUrl":"https://doi.org/10.1155/2015/520893","url":null,"abstract":"We propose a simple computer based phenomenological model to simulate the characteristics of river flow velocity in large scale. We use shuttle radar tomography mission based digital elevation model in grid form to define the terrain of catchment area. The model relies on mass-momentum conservation law and modified equation of motion of falling body in inclined plane. We assume inelastic collision occurs at every junction of two river branches to describe the dynamics of merged flow velocity.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/520893","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65012605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Identification of Gas Sand Horizons of the Rashidpur Structure, Surma Basin, Bangladesh, Using 2D Seismic Interpretation","authors":"A. Islam, Md. Ahosan Habib","doi":"10.1155/2015/840168","DOIUrl":"https://doi.org/10.1155/2015/840168","url":null,"abstract":"A total of 13 seismic sections were used for 2D seismic interpretation in order to assess the subsurface geometry of gas sand horizons and hydrocarbon prospect of the Rashidpur structure, Surma Basin, Bangladesh. Out of five reflectors, two selected reflectors were mapped for the study. The top of the Upper Gas Sand (R3) reflector was elongated in N-S with the axis swinging slightly to the east on the northern plunge. North-South trending thrust fault was identified in the eastern part which is parallel to the axial line of the structure. The reflection patterns of the gas sand horizons were parallel to each other and similar in nature. The reflection coefficients were positive at the base and negative at the top of the each gas sand horizons. Velocity dropped from 2562 m/s to 2177 m/s in the Upper Gas Sand (R3) and 4320 m/s to 3413 m/s in the Lower Gas Sand (R5) reflector. Bright spot and amplitude anomalies were identified on the top of the both gas sand horizons. The result depicts that the shape of the gas sand horizons is asymmetric anticline. The structure is compressed and elongated NNW-SSE trending anticline. The study reveals hydrocarbon potentiality of the structure.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/840168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65177628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Geophysical Contribution in the Characterization of Deep Water Tables Geometry (Sidi Bouzid, Central Tunisia)","authors":"D. Khazri, H. Gabtni","doi":"10.1155/2015/239797","DOIUrl":"https://doi.org/10.1155/2015/239797","url":null,"abstract":"Geophysical data combined with geological and hydrogeological data were analyzed to characterize the geometry of Oued El Hajel and Ouled Asker deep water tables (Sidi Bouzid). The obtained results allowed refining the geostructural schema by highlighting the individualization of the NE-SW underground convexity of Ouled Asker and the anticline of axis Es Souda-Hmaeima and Ezaouia on either sides of two hydrogeological thresholds. The geometrical analysis determined the spatial extension of Ouled Asker and Oued El Hajel subbasins. The seismic cartography of semideep and deep reservoirs (Oligo-Miocene; Eocene and upper Cretaceous) associated with the main subbasins contributed to proposing hydrogeological prospect zones for a rationalized groundwater exploitation.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/239797","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64855956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Acoustic-Gravity Waves Interacting with a Rectangular Trench","authors":"U. Kadri","doi":"10.1155/2015/806834","DOIUrl":"https://doi.org/10.1155/2015/806834","url":null,"abstract":"A mathematical solution of the two-dimensional linear problem of an acoustic-gravity wave interacting with a rectangular trench, in a compressible ocean, is presented. Expressions for the flow field on both sides of the trench are derived. The dynamic bottom pressure produced by the acoustic-gravity waves on both sides of the trench is measurable, though on the transmission side it decreases with the trench depth. A successful recording of the bottom pressures could assist in the early detection of tsunami.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2015-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/806834","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65157930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Zero-Offset VSP Monitoring of CO2 Storage: Impedance Inversion and Wedge Modelling at the Ketzin Pilot Site","authors":"Julia Götz, S. Lüth, C. Krawczyk, C. Cosma","doi":"10.1155/2014/294717","DOIUrl":"https://doi.org/10.1155/2014/294717","url":null,"abstract":"At the CO2 storage pilot site near the town of Ketzin (35 km west of Berlin, Germany) the sandstone reservoir at 630 m–650 m depth is thin and heterogeneous. The time-lapse analysis of zero-offset VSP measurements shows that CO2-induced amplitude changes can be observed on near-well corridor stacks. Further, we investigate whether CO2-induced amplitude changes in the monitoring data can be used to derive geometrical and petrophysical parameters governing the migration of CO2 within a brine saturated sandstone aquifer. 2D seismic-elastic modelling is done to test the processing workflow and to perform a wedge modelling study for estimation of the vertical expansion of the CO2 plume. When using the NRMS error as a measure for the similarity between the modelled and recorded repeat traces, the best match is achieved for a plume thickness of 6-7 m within the reservoir sandstone of 8 m thickness. With band limited impedance inversion a velocity reduction at the top of the reservoir of 30%, influenced by casing reverberations as well as CO2 injection, is found. The relation of seismic amplitude to CO2 saturated layer thickness and CO2-induced changes in P-wave velocities are important parameters for the quantification of the injected CO2 volume.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2014-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/294717","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64428367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Diacritical Seismic Signatures for Complex Geological Structures: Case Studies from Shushan Basin (Egypt) and Arkoma Basin (USA)","authors":"M. Abdel-Fattah, H. Alrefaee","doi":"10.1155/2014/876180","DOIUrl":"https://doi.org/10.1155/2014/876180","url":null,"abstract":"Seismic reflection techniques show an imperative role in imaging complex geological structures and are becoming more acceptable as data interpreting tools in 2D/3D view. These subsurface geological structures provide complex seismic signature due to their geometrical behavior. Consequently, it is extremely difficult to interpret these seismic sections in terms of subsurface configuration. The main goal of this paper is to introduce seismic attributes as a powerful tool to interpret complex geological structures in different geological settings. In order to image these complex geological features, multiple seismic attributes such as coherence and curvature have been applied to the seismic data generated over the Shushan Basin (Egypt) and Arkoma Basin (USA). Each type of geological structure event usually generates a unique seismic “signature” that we can recognize and identify by using these seismic attributes. In Shushan Basin (Egypt), they provide a framework and constraint during the interpretation and can help prevent mistakes during a 3D structural modeling. In Arkoma Basin (USA), the seismic attributes results provide useful information for broader analyses of the complex structural relations in the region where the Ouachita orogenic belt intersects with the southern Oklahoma aulacogen. Finally, complex geological structures provide dramatically diacritical seismic signatures that can be easily interpreted by collaborating conventional seismic interpretation techniques with multiple seismic attributes.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/876180","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64722875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Integrated Approach to Investigate the Effect of Leachate on Groundwater around the Ikot Ekpene Dumpsite in Akwa Ibom State, Southeastern Nigeria","authors":"N. George, A. Ubom, J. Ibanga","doi":"10.1155/2014/174589","DOIUrl":"https://doi.org/10.1155/2014/174589","url":null,"abstract":"Geophysical, geochemical, and hydrogeological measurements have been integrated to assess the effect of leachate on groundwater quality within the dumpsite in Ikot Epene Local Government Area of Akwa Ibom State, Southern Nigeria, and its environs. The resistivity values and depth of burial of the geomaterials, constrained by geology, were used in producing resistivity cross sections which show the geoelectric distribution of the subsurface near and away from the dumpsite. The observed high conductivity in subsurface layers closed to the dumpsite is symptomatic of the leachate-loaded conductive fluid leached and drained into the subsurface. The hydrochemical results of some species conform to WHO standards, while some were found to be relatively higher due to dissolution, leaching, and draining of leachate related contaminants in the soil. The correlation indices of the ion pairs show no significant effect on the paired ions, indicating that the significant value of some of the individual ions is not geologic but due to precipitation from the leachate residue. In general, the effect of leachate is more dominant in the immediate groundwater pathway near the dumpsite than aquifer repositories away from it. The crossplots of the water resistivity and bulk resistivity show exponential increase for the different layers.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2014-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/174589","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64377217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Delineation of Fractured Aquifer Using Numerical Analysis (Factor) of Resistivity Data in a Granite Terrain","authors":"R. Andrade","doi":"10.1155/2014/585204","DOIUrl":"https://doi.org/10.1155/2014/585204","url":null,"abstract":"In hard rock terrain, fractured aquifers comprise the major source of groundwater availability where the phreatic aquifer is desaturated. Identification of fracture zones in hard rock terrain and potential groundwater source delineation had been a perennial problem in hydrology. The purpose of this paper is to highlight the study over a small watershed area, in a granite terrain, wherein an attempt was made to delineate and map the fractured aquifer using numerical (factor) analysis of the conventional vertical electrical sounding data, which was obscure in curve matching technique. This numerical approach in concatenation with resistivity imaging or other techniques would prove to be an effective tool in groundwater exploration.","PeriodicalId":45602,"journal":{"name":"International Journal of Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2014-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/585204","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64559756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}