Compressibility of porous rocks: Part I. Measurements of Hungarian reservoir rock samples     

Ali Ahmed Jalalh 《Acta Geophysica》2006,54(3):319-332

Pore volume compressibility is one of the physical properties of a reservoir that must be specified in many reservoir-engineering calculations. In the presented research, the effect of compact pressure, temperature and porosity on compressibility was investigated. A total of twenty-two different cores were tested: five limestone, one friable sandstone, fourteen medium to hard sandstone, and two very dense sandstone. Core samples were placed in the test cell and subject to compacting pressure up to 10,000 psi. Runs were made at room temperature and at 52°C for limestone samples. Although there were some publications concerning measurement and study of the effect of pressure and temperature on pore volume compressibility of reservoir rocks, nothing has been published about compressibility of Hungarian reservoir rocks, except of the work of Tóth and Bauer (1988). The present study showed pore volume compressibility data for different Hungarian fields. The result of the study at high temperature (52°C) shows that pore compressibility increases with increasing temperature.  相似文献   

Another look at the 1993 and 1995 Gulf of Aqaba earthquakes from the analysis of teleseismic waveforms   总被引：3，自引：0，他引：3  

Ali K. Abdel-Fattah  H. M. Hussein  S. El-Hady 《Acta Geophysica》2006,54(3):260-279

In this work we estimated the source process and the source parameters of the 1993 and 1995 Gulf of Aqaba earthquakes. To investigate the source process of both events, we inverted the teleseismic P- and SH-waveform data using an iterative technique in which the rupture is modeled as a series of point source subevents with varying mechanisms. The main source process of the 1993 event can be explained by two subevents with essentially the same mechanism. These two subevents had different focal depths. The second subevent was about 5 s later than the first one and about 70% of the moment rate released with the second one. The total rupture duration time was about 12 s. Our solution for the 1995 Gulf of Aqaba earthquake indicated that the event consists of three subevents with various fault geometries and about 60% of the moment released by the second subevent. The first subevent occurred at a depth of 13 km, and was followed after 9 s by the second one at a depth of 11 km; the third subevent, at a depth of 9 km occurred 19 s after the second one. The total duration of the earthquake rupture process was about 18.7 s. The obtained mechanisms for the 1993 and 1995 Gulf of Aqaba earthquakes are well correlated with the structural setting of the Gulf of Aqaba.  相似文献   

Recent crustal deformation of İzmir, Western Anatolia and surrounding regions as deduced from repeated GPS measurements and strain field     

Bahad&#x;r Aktu  Ali K&#x;l&#x;olu 《Journal of Geodynamics》2006,41(5):471-484

To investigate contemporary neotectonic deformation in İzmir, Western Anatolia and in its neighborhood, a relatively dense Global Positioning System (GPS) monitoring network was established in 2001. Combination of three spatially dense GPS campaigns in 2001, 2003 and 2004 with temporally dense campaigns between 1992 and 2004 resulted in a combined velocity field representing active deformation rate in the region. We computed horizontal and vertical velocity fields with respect to Earth-centered, Earth-fixed ITRF2000, to Eurasia and to Anatolia as well.The rates of principal and shear strains along with rigid-body rotation rates were derived from velocity field. Results show east–west shortening between Karaburun Peninsula and northern part of İzmir Bay together with the extension of İzmir Bay in accordance with general extension regime of Western Anatolia and Eastern Agea. East–west shortening and north–south extension of Karaburun Peninsula are closely related to right-lateral faulting and a clockwise rotation. There exists a block in the middle of the peninsula with a differential motion at a rate of 3–5 ± 1 mm/year and 5–6 ± 1 mm/year to the east and south, respectively.As is in Western Anatolia, north–south extension is dominant in almost all parts of the region despite the fact that they exhibit significantly higher rates in the middle of the peninsula. Extensional rates along Tuzla Fault lying nearly perpendicular to İzmir Bay and in its west are maximum in the region with an extension rate of 300–500 ± 80–100 nanostrain/year and confirm its active state. Extensional rates in other parts of the region are at level of 50–150 nanostrain/year as expected in the other parts of Western Anatolia.  相似文献   

Single piles under horizontal loads in sand: determination of <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">Y</Emphasis> curves from the prebored pressuremeter test     

Ali Bouafia 《Geotechnical and Geological Engineering》2007,25(3):283-301

Lateral load-deflection behaviour of single piles is often analysed in practice on the basis of methods of load-transfer P–Y curves. The paper is aimed at presenting the results of the interpretation of five full-scale horizontal loading tests of single instrumented piles in two sandy soils, in order to define the parameters of P–Y curves, namely the initial lateral reaction modulus and the lateral soil resistance, in correlation with the pressuremeter test parameters. P–Y curve parameters were found varying as a power of lateral pile/soil stiffness, on the basis of which hyperbolic P–Y curves in sand were proposed. The predictive capabilities of the proposed P–Y curves were assessed by predicting the soil/pile response in full-scale tests as well as in centrifuge tests and a very good agreement was found between the computed deflections and bending moments, and the measured ones. Small-sized database of full-scale pile loading tests in sand was built and a comparative study of some commonly used P–Y curve methods was undertaken. Moreover, it was shown that the load-deflection curves of these test piles may be normalised in a practical form for an approximate evaluation of pile deflection in a preliminary stage of pile design. At last, a parametric study undertaken on the basis of the proposed P–Y curves showed the significant influence of the lateral pile/soil stiffness on the non-linear load-deflection response.  相似文献   

新疆南部地区暖冬年与春夏季降水的相关分析     

霍文  艾力·买买提明  刘新春  尚华明  秦贺 《干旱区地理》2007,30(2):257-261

利用春夏季(3~8月)12个站降水资料以及冬季(12~02月)温度资料,通过统计方法选取新疆南部地区温度异常年份与春夏季降水异常年份,并进行相关分析,结果表明:暖冬年份对应的来年春夏季总降水量偏多;反之,冷冬年对应的春夏季降水总量偏少。再利用NCEP/NCAR1960-2000年全球月平均网格点资料分析500 hPa高度场环流特征,结果表明:暖冬年前期环流特征为西低东高型,冷冬年前期环流特征为西高东低型,具有反位相关系。暖冬年后期才为西高东低型,与冷冬年前期相较起点晚,从而影响到来年的环流入夏时间,这可能就是导致暖冬年份来年降水增多的原因之一。  相似文献   

Groundwater Deterioration of Shallow Groundwater Aquifers Due to Overexploitation in Northeast Jordan     

Ali El‐Naqa  Mohammad Al‐Momani  Suzan Kilani  Nezar Hammouri 《洁净——土壤、空气、水》2007,35(2):156-166

Groundwater is the major water resource in Jordan and most of the groundwater basins are already exploited beyond their estimated safe yield. Azraq basin is one of the most important groundwater basins in Jordan, which supplies Amman with drinking water. However, due to overpumping from the shallow groundwater aquifers, the water level dropped dramatically and signs of salinization and depletion are starting to occur. The severe drawdown in the Azraq well‐field caused a reverse in the hydraulic gradient and consequently, the saltwater in the center of the basin (Qa‐Azraq) started to move in the direction of the well‐field. The salinization in the shallow aquifer (basalt/B5/B4) is believed to result from one of the following scenarios: (i) a reverse flow from Sabkha to the AWSA well field, (ii) an upward leakage from the middle aquifer system (B2/A7) and the combined B3 Aquitard‐B2/A7 aquifer, (iii) a dissolution process between the water and rock matrix due to lowering of the dynamic water levels during pumping which reached the mineralized formations underlying the Basalt. The salinization trend of some AWSA wells represented by the gradual increase of major ions is associated with rather constant stable isotopic contents. This indicates that these constituents originate from the main minerals existing in the matrix of the aquifers and thus this scenario is the most likely to occur.  相似文献   

Estimating the economic potential for agricultural soil carbon sequestration in the Central United States using an aggregate econometric-process simulation model     

John M. Antle  Susan M. Capalbo  Keith Paustian  Md Kamar Ali 《Climatic change》2007,80(1-2):145-171

The purpose of this paper is to develop and apply a new method to assess economic potential for agricultural greenhouse gas mitigation. This method uses secondary economic data and conventional econometric production models, combined with estimates of soil carbon stocks derived from biophysical simulation models such as Century, to construct economic simulation models that estimate economic potential for carbon sequestration. Using this method, simulations for the central United States show that reduction in fallow and conservation tillage adoption in the wheat-pasture system could generate up to about 1.7 million MgC/yr, whereas increased adoption of conservation tillage in the corn–soy–feed system could generate up to about 6.2 million MgC/yr at a price of $200/MgC. About half of this potential could be achieved at relatively low carbon prices (in the range of $50 per ton). The model used in this analysis produced estimates of economic potential for soil carbon sequestration potential similar to results produced by much more data-intensive, field-scale models, suggesting that this simpler, aggregate modeling approach can produce credible estimates of soil carbon sequestration potential. Carbon rates were found to vary substantially over the region. Using average carbon rates for the region, the model produced carbon sequestration estimates within about 10% of those based on county-specific carbon rates, suggesting that effects of spatial heterogeneity in carbon rates may average out over a large region such as the central United States. However, the average carbon rates produced large prediction errors for individual counties, showing that estimates of carbon rates do need to be matched to the spatial scale of analysis. Transaction costs were found to have a potentially important impact on soil carbon supply at low carbon prices, particularly when carbon rates are low, but this effect diminishes as carbon prices increase. This research was supported in part by the Montana State Agricultural Experiment Station, by the EPA STAR Climate Change program and by the Consortium for the Agricultural Mitigation of Greenhouse Gases. Although the research described in this article has been funded wholly or in part by the United States Environmental Protection Agency through grant R-82874501-0 to Montana State University, it has not been subjected to the Agency’s required peer and policy review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred.  相似文献   

Spatial prediction model and its application to chemistry of atmospheric precipitation in Jordan     

Omar Ali Al-Khashman  Qassem Y. Tarawneh 《Atmospheric Research》2007,84(4):399-409

This study is concerned with the spatial variability of some wet atmospheric precipitation parameters such as; pH, conductivity (EC). The study also depicts the spatial variability of some ions (cations and anions) of atmospheric precipitation in Jordan such as, Ca²⁺, Mg²⁺, Na⁺ and K⁺, HCO₃⁻, Cl⁻, NO₃⁻ and SO₄²⁻. The basis of the work is to establish a relationship through the cumulative semivariogram technique between the distance ratios and the spatial dependence structure of the chemical composition of atmospheric precipitation. All semivariogram models are constructed in this study in order to understand the behavior of the spatial distribution. The spatial distributions of rainwater parameters show differences from station to station which is expressed in terms of angle, where the larger the angle the weaker the correlation. The semivariogram (SV) models are constructed to show the variation of the rainfall chemistry in Jordan. The SV models show weak correlation between mountain and leeside mountain stations, i.e. mountain and desert stations. On the other hand, good correlations are observed when transferring from south to north of the country. The larger is the found angle, the weaker is the correlation. For most of the SV model the correlation is found to be very weak between desert and mountainous locality. The Standard Regional Dependence Factor (SRDF) is used for prediction of the distribution of rain fall parameters. It shows the relative error between observed and predicted values of rainwater parameters. The overall regional relative error between the observed and estimated concentrations remains less than 15%.  相似文献   

(Im)mobilization of soil heavy metals using CaO,FA, sulfur,and Na<Subscript>2</Subscript>S: a 1-year incubation study     

A. Mahar  P. Wang  A. Ali  A. H. Lahori  M. K. Awasthi  Z. Wang  Z. Guo  Q. Wang  S. Feng  R. Li  Z. Zhang 《International Journal of Environmental Science and Technology》2018,15(3):607-620

The immobilization of heavy metals (HMs)-contaminated soils using amendments is a cost-effective remediation technique. Therefore, the aim of this study was to evaluate the effectiveness and aging factor of CaO, fly ash (FA), sulfur, and Na₂S on the immobilization of Cd, Cu, and Pb in three different contaminated soils under 1-year incubation. The study sites (S) and amendments treatments (T) are termed as S1, S2, and S3 and T1, T2, T3, and T4, respectively. The TCLP-extractable HMs were analyzed in treated soils after 2, 6, and 12 months. The higher concentrations of CaO, FA, and Na₂S (T3 and T4) efficiently immobilized the Cd. However, a moderate Cd decrease was noted in sulfur-treated samples with no significant difference in ratios as compared to control in used soils. Likewise, CaO decreased moderately Cu content in used soils with gradual increase in Cu mobility. Similarly, FA, sulfur, and Na₂S showed effective immobilization of Cu content with no difference in treatment ratios as compared to control. In addition, CaO, sulfur, and Na₂S decreased the significant content of Pb as compared to control. However, FA treatments showed moderate reduction in Pb content with no difference in ratios. The higher concentrations of alkaline amendments should be avoided in the farmland soils as they increase the soil pH and EC of soil ecosystem. The higher ratios of alkaline amendments would be suitable to remediate the abandoned lands/brownfields. The sulfur amendment would be suitable for immobilization of metals in alkaline soils rather than in acidic soils.  相似文献   

Critical state behaviour of weakly bonded soil in drained state     

Z. Ali Rahman  D. G. Toll  D. Gallipoli 《Geomechanics and Geoengineering》2018,13(4):233-245

A series of consolidated drained triaxial test was performed on weakly bonded soils that were artificially prepared by mixing sand (87%) and kaolin (13%). To create weakly bond strength, samples were fired at 500°C for 5 h. A critical state (CS) concept was used to interpret the results in order to describe the behaviour of the studied soil. Defining the CS is not always straightforward. Several tests showed changing in deviator stress q and volumetric strain ε_v up to the end of tests. Hence, defining the CS requires careful assessments on q–ε_a, Δu–ε_a, q–p′ and v–ln p′ spaces which were performed. A ‘discontinuity’ approach was applied to position the CS on dilatant path in v–ln p′ spaces after considering stress-strain and volumetric strain curves. The critical state line in a v–ln p? space from bonded samples exhibited differences to the destructured samples. This suggests that the influence of cementation bond is substantially clear at lower stresses but as stresses increase beyond the stress yield, cementation degradation becomes more significant. The effect of bonding can be clearly visualised from the normalisation of the stress paths of destructured and bonded samples.  相似文献