Acoustic and petrophysical relationships in low-shale sandstone reservoir rocks     

Jalal Khazanehdari  Clive McCann 《Geophysical Prospecting》2005,53(4):447-461

This paper describes the measurements of the acoustic and petrophysical properties of two suites of low‐shale sandstone samples from North Sea hydrocarbon reservoirs, under simulated reservoir conditions. The acoustic velocities and quality factors of the samples, saturated with different pore fluids (brine, dead oil and kerosene), were measured at a frequency of about 0.8 MHz and over a range of pressures from 5 MPa to 40 MPa. The compressional‐wave velocity is strongly correlated with the shear‐wave velocity in this suite of rocks. The ratio V_P/V_S varies significantly with change of both pore‐fluid type and differential pressure, confirming the usefulness of this parameter for seismic monitoring of producing reservoirs. The results of quality factor measurements were compared with predictions from Biot‐flow and squirt‐flow loss mechanisms. The results suggested that the dominating loss in these samples is due to squirt‐flow of fluid between the pores of various geometries. The contribution of the Biot‐flow loss mechanism to the total loss is negligible. The compressional‐wave quality factor was shown to be inversely correlated with rock permeability, suggesting the possibility of using attenuation as a permeability indicator tool in low‐shale, high‐porosity sandstone reservoirs.  相似文献   

Impact of flash flood recharge on groundwater quality and its suitability in the Wadi Baysh Basin,Western Saudi Arabia: an integrated approach     

Milad H. Z. Masoud  Jalal M. Basahi  Natarajan Rajmohan 《Environmental Earth Sciences》2018,77(10):395

An integrated approach was used to evaluate the impact of flash flood recharge on groundwater quality and its suitability for drinking, irrigation, livestock and poultry uses in the Wadi Baysh Basin, Western Saudi Arabia. Analyses of 182 groundwater samples, collected from the study area before and after a flash flood (FF) event, show that the average concentrations of TDS, Mg, Na, Cl, NO₃ and EC decreased significantly after the event. The major water types (mixed CaMgCl, NaCl and CaCl) indicate that the infiltration of surface water from FF recharge has a great influence on groundwater chemistry. Drinking water suitability maps, created using WHO standards, indicate that wells located in the upstream region are suitable for drinking despite their high TDS and total hardness (TH) values. Groundwater in the coastal region is unsuitable due to its high salinity, high TH and high concentrations of major ions. The suitability of groundwater for irrigational use was assessed using salinity, sodium adsorption ratio, bicarbonate hazard, residual sodium carbonate, Kelly’s ratio, magnesium hazard, sodium percentage and permeability index values, which indicated that groundwater in the study region is suitable for most soils and crops. After FF, groundwater quality is improved by dilution, especially in the downstream region. USSL classification shows that the majority of the water samples are in the C3S1, C4S2, and C3S2 classes and are therefore suitable for the irrigation of salt-tolerant crops. Irrigational suitability maps suggest that wells in the upstream region are suitable for irrigation, whereas wells located near to the coast are unfit for irrigation. This study implies that construction of check dams in the dry valleys (wadies) may improve the groundwater quality in the area.  相似文献   

Precipitation pattern modeling using cross-station perception: regional investigation     

Sadeq Oleiwi Sulaiman  Jalal Shiri  Hamed Shiralizadeh  Ozgur Kisi  Zaher Mundher Yaseen 《Environmental Earth Sciences》2018,77(19):709

Establishing robust models for predicting precipitation processes can yield a significant aspect for many applications in water resource engineering and environmental prospective. In particular, understanding precipitation phenomena is crucial for managing the effects of flooding in watersheds. In this research, a regional precipitation pattern modeling was undertaken using three intelligent predictive models incorporating artificial neural network (ANN), support vector machine (SVM) and random forest (RF) methods. The modeling was carried out using monthly time scale precipitation information in a semi-arid environment located in Iraq. Twenty weather stations covering the entire region were used to construct the predictive models. At the initial stage, the region was divided into three climatic districts based on documented research. Initially, modeling was carried out for each district using historical information from regionally distributed meteorological stations for calibration. Subsequently, cross-station modeling was undertaken for each district using precipitation data from other districts. The study demonstrated that cross-station modeling was an effective means of predicting the spatial distribution of precipitation in watersheds with limited meteorological data.  相似文献   

Spatial distribution of regionalized variables on reservoirs and groundwater resources based on geostatistical analysis using GIS: case of Rmel-Oulad Ogbane aquifers (Larache,NW Morocco)     

Mohamed Jalal El Hamidi  Abdelkader Larabi  Mohamed Faouzi  Mohamed Souissi 《Arabian Journal of Geosciences》2018,11(5):104

In many countries of the world, groundwater is the main source of water in arid and semiarid regions. The scarcity of water is one of the main issues in Morocco. The coastal aquifer system of Rmel-Oulad Ogbane is recognized as one of the most important aquifers in Morocco and is very well known for their role in industrial, economic, and social development. However, this role is confronted to climate change impacts and heavy abstraction rates leading to a major decline in the groundwater levels and may eventually cause a deficit water balance of the aquifer as well as a degradation of the freshwater quality by seawater intrusion. The objective of this research is to identify and evaluate the distribution and spatial changes of regionalized variables on reservoirs and groundwater resources using geostatistical analysis in Geographic Information System (GIS) software. The prediction of these variables was performed using an interpolation method: ordinary kriging in a GIS. The normality test and trend analysis were applied to each variable to select the appropriate semivariogram model (SVM) and check the results using cross-validation (CV). Hence, several kriged maps of reservoirs and water resources have been produced to be exploited by the decision maker. The studied variables related to reservoirs and hydrodynamic data have a strong spatial dependence, which show correlations in specific direction, while the hydrochemical data are mainly related to groundwater mechanisms, such as advective-diffusive transport, without any autocorrelation between data.  相似文献   

Sensitivity analysis of the seismic demands of RC moment resisting frames to different aspects of ground motions   总被引：1，自引：0，他引：1       下载免费PDF全文

Jalal Kiani  Shahram Pezeshk 《地震工程与结构动力学》2017,46(15):2739-2755

A weight vector representing the relative importance of various characteristics of ground motions (GMs) and a conditioning intensity measure (IM) are required to be able to use the generalized conditional IM framework for the purpose of GM selection. An inappropriate weight vector may result in the biased distributions of some important characteristics of GMs and, consequently, the bias in the structural responses. This article aims to provide the analyst with the understanding of which properties of GMs are important in capturing the accurate structural responses, to specifically assign a suitable weight to them and to select an appropriate conditioning IM as well. To this end, 4 reinforced concrete buildings, located at the site in which the seismic hazard is dominated by shallow crustal earthquakes, are considered. The findings reveal that the appropriate weight vectors depend on the characteristics of the employed structural systems. In addition, the role played by each IM in capturing the true structural responses changes over different earthquake intensity levels implying that different weight vectors are required over different earthquake levels. Furthermore, this study shows that, even in case of shorter‐duration GMs from shallow events, GM duration should be incorporated in GM selection as it has effects on the peak‐based structural responses in the earthquake levels beyond the level of 2%‐in‐50‐years. Specifically, the findings reveal that in case of shallow events, unlike large magnitude earthquakes, the shorter the duration of GM the more rapid release of energy and, consequently, the larger the peak‐based structural responses.  相似文献   

Radish (Raphanus sativus L.) Cultivar‐Specific Response to O3: Patterns of Biochemical and Plant Growth Characteristics          下载免费PDF全文

Ibrahim A. Hassan  Nigel B. Bell  Mike R. Ashmore  Lorenzo Cotrozzi  Nesreen S. Haiba  Jalal M. Basahi  Ahmad Summan  Talal Almeelbi  Iqbal M. Ismail 《洁净——土壤、空气、水》2018,46(6)

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Predicting daily pan evaporation by soft computing models with limited climatic data     

Sungwon Kim  Jalal Shiri  Vijay P. Singh  Ozgur Kisi  Gorka Landeras 《水文科学杂志》2013,58(6):1120-1136

Abstract

Accurate prediction of daily pan evaporation (PE) is important for monitoring, surveying, and management of water resources as well as reservoir management and evaluation of drinking water supply systems. This study develops and applies soft computing models to predict daily PE in a dry climate region of south-western Iran. Three soft computing models, namely the multilayer perceptron-neural networks model (MLP-NNM), Kohonen self-organizing feature maps-neural networks model (KSOFM-NNM), and gene expression programming (GEP), were considered. Daily PE was predicted at two stations using temperature-based, radiation-based, and sunshine duration-based input combinations. The results obtained by the temperature-based 3 (TEM3) model produced the best results for both stations. The Mann-Whitney U test was employed to compute the rank of different input combination for hypothesis testing. Comparison between the soft computing models and multiple linear regression model (MLRM) demonstrated the superiority of MLP-NNM, KSOFM-NNM, and GEP over MLRM. It was concluded that the soft computing models can be successfully employed for predicting daily PE in south western Iran.