缝洞向井筒供液时三重压敏介质油藏压力响应特征研究

建立由基岩系统、裂缝系统和溶洞系统组成，并考虑溶洞渗透率和裂缝渗透率随压降的增加呈指数减小的三重压敏介质油藏试井解释模型，采用隐式差分格式对考虑井筒储存和污染效应的情况进行了求解。讨论了溶洞和裂缝无因次渗透率模数、介质问窜流、弹性储容比、外边界条件及表皮系数对压力响应的影响。结果表明：无因次渗透率模数导致压力及压力导数明显上升，窜流系数影响窜流阶段出现的早晚，弹性储容比影响压力导数曲线“凹陷”的宽度和深度，外边界条件的影响则和普通三重介质明显不同，表皮系数主要影响全部压力和压力导数早期的“凸起”，而无因次渗透率模数则主要影响压力和压力导数的后期。     

三重介质分支水平井试井分析

基于裂缝向井底供液,存在溶洞和裂缝、基岩和裂缝之间的窜流的三重介质模型,建立了这类介质的水平分支井数学模型,并利用源函数和Laplace变换,结合泊松叠加公式和贝塞尔函数积分等方法,解得了分支水平井在拉普拉斯空间下的井底压力解,绘制了三重介质分支水平井试井曲线.指出三重介质分支水平井完整的试井曲线存在八个流动阶段.溶洞和裂缝间的窜流系数主要影响第一下凹段出现时间的早晚,而基岩和裂缝间的窜流系数影响第二个下凹段;溶洞的弹性储容比影响两个下凹的深浅,裂缝的弹性储容比只影响第一个下凹深浅.双重介质只出现一个下凹段,而三重介质出现两个下凹段.     

裂缝和洞与井筒连通的三重介质油藏试井解释方法研究

针对由基岩、裂缝和溶洞组成的三重介质油藏提出了裂缝和洞与井筒连通的试井解释模型,建立了相应的数学模型,并采用Laplace变换和数值Laplace反演方法进行了求解,分析了介质的弹性储容比、窜流因子以及裂缝渗透率比对压力响应的影响,同时还提出了三重介质油藏的试井解释方法——利用遗传算法进行自动拟合,并编制了实用软件,实例分析表明了该新方法的可靠性和实用性。     

双重介质中有限导流垂直裂缝井试井模型求解的新方法

在T.A.Blasingame等人提出的均质油藏中有限导流垂直裂缝试井模型（TPR）的基础上采用Laplace变换与反演技术,完成了双重孔隙介质中有限导流垂直裂缝井试井模型的求解新算法.讨论了介质间窜流、弹性储容比、裂缝导流能力及外边界条件对压力动态的影响,结果表明：用该方法计算的结果与经典的双重介质垂直裂缝井模型一致.这种算法计算速度快,精度满足要求,可用于现代试井分析的自动拟合中.     

三重介质油藏斜井压力动态特征分析

针对裂缝与井筒连通,同时存在溶洞和裂缝、基岩和裂缝之间发生拟稳态窜流的三重介质,建立了这类三重介质油藏的斜井试井解释模型,采用汇源叠加等方法求得顶底封闭无限大三重介质油藏斜井在拉氏空间中的井底压力响应,绘制了相应的典型无因次压力曲线版图,分析了顶底封闭无限大三重介质油藏斜井的渗流规律,对其压力特征曲线进行了流动阶段的划分,并讨论了影响压力特征曲线的各种因素。所得的结果有利于提高对三重介质油藏斜井渗流规律的认识,为合理地运用斜井开发三重介质油藏提供理论依据。     

任意形状复合油藏压力动态的边界元分析

油气藏形状对井底压力动态响应有着显著的影响，常规的解析方法只能计算规则形状油气藏的井底压力响应。该文建立了任意形状复合油藏不稳定渗流的数学模型，并将区域分割法与边界元方法相结合，研究了任意形状复合油藏不稳定压力响应的计算方法，应用杜哈美原理考虑了表皮效应与井储系数对井底压力动态响应的影响。绘制并分析了复合油藏的典型曲线，通过分析指出油藏的边界性质会影响典型曲线后期形态，而内区形状的也可能掩盖复合油藏典型曲线的特点。     

缝洞型油藏三重介质油水两相流数值试井解释方法

基于多重介质渗流的概念模型和数学模型,建立了缝洞型油藏油水两相流三重介质数值试井模型;对模型进行数值求解,得到三重介质油藏两相流试井响应曲线并分析其特征。指出三重介质油水两相条件下的压恢曲线与单相时的不重合,并随着初始油水饱和度的变化而变化,不能直接用单相试井模型来解释两相流试井曲线;提出了先拟合油水产量曲线,再拟合压力恢复曲线的试井解释方法。     

低速非达西双渗油藏DST段塞流测试渗流模型及应用

本文在分析了实际低速非达西双渗油藏DST段塞流测试非自喷井渗流规律的基础上，导出了其有效井径数学模型，利用Laplace变换及特殊物理方程理论，导出了该模型的拉氏空间解析解，利用Stehfest数值算法进行数值反演，得出了实空间解，并绘制了无因次样板曲线。结果表明：启动压力梯度、层问储容比、地层系数比的变化对段塞流试井解释结果有较大的影响。当窜流系数比较大时，在晚期段曲线几乎相交于同一条曲线；但是当窜流系数比较小时，层间储容比、地层系数之比对于压力曲线的后期段有较大的影响，曲线后期段上翘。采用本模型绘制的样板曲线，能较大程度上提高拟合精度，可有效运用于现场DST段塞流试井分析。     

低渗透油藏毛细管压力动态效应的数值模拟研究

实验分析和理论研究表明毛细管压力存在动态效应,即其与润湿相流体的饱和度变化率相关,已有的物理实验表明低渗透油藏中的毛细管压力动态效应对于油气渗流存在着较大的影响。该文首先根据23个低渗岩心渗流曲线的数值拟合分析结果,建立了各项物理意义明确的非线性渗流运动方程,然后通过构造三种不同的饱和度变化速率的润湿相流体饱和度时变曲线,利用有限元数值方法模拟了三种饱和度曲线对应下的一维水驱油过程,并在完全基于数学方法较少依赖于物理实验的基础上计算了毛细管压力曲线。数值模拟的结果表明,低渗透油藏中存在较为明显的毛细管压力动态效应,且动态系数与介质的固有渗透率负相关,与润湿相流体的黏滞系数正相关。并通过与达西线性渗流模拟结果的对比表明了低渗油藏中非线性渗流产生的毛细管压力动态效应更为明显,动态系数也更大。     

双孔介质油藏多层合采油井产能分析

此文在分析多层双孔介质油藏渗流规律的基础上,考虑各层具有不同的物性参数和原始地层压力,建立了考虑井储和表皮影响的无窜流多层双孔介质油藏渗流模型.通过Laplace变换,求解得到了拉氏空间内的井底压力和各层产量的解析解,并根据数值反演方法编程绘制了各层产量的理论变化曲线,分析了分层产量变化的规律及影响因素.此文的研究结果可以指导现场的油井合理配产.     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

浅谈优化Vray渲染在制作三维场景的应用研究

用Vray三维渲染引擎来渲染三维场景,其质量和速度是由一些影响因素和参数设置决定的,不同的参数和因素,可以得出不同的三维渲染效果.因此,分析、优化三维渲染质量和速度的影响因素,正确、合理的选择参数对提高Vray最后渲染阶段的质量和速度非常重要.     

固结、渗流和沉积控制方程研究

本文从两相流体动力学的守恒方程出发，考虑固相、液相的相对运动，推导了可以考虑场的不均匀性和流体压缩性的统一形式的控制方程，并对方程所基于的物理概念和相互联系进行了必要的分析。通过对方程适当形式的表达，可导出用于大、小变形固结、渗流和沉积的简化方程，显示了在不同领域的三个理论存在一定的统一性。方程推导过程并未对本构关系加以限制，适用范围较广。依据实际问题的要求，作了不同形式的简化。     

四川省及重庆市中型水电站效益分析

该文分析了四川省及重庆市几座中型水电站的调查材料表明：四川省及重庆市中型水电站不仅在川渝主网和地方电网中起着很大的作用，并具有巨大的社会效益，同时还有综合利用效益，说明修建中型水电站的优越性．     

Site modelling methods for detecting hydrologic alteration of flood frequency and flood duration in the floodplain below the carlyle dam,lower Kaskaskia River,Illinois, USA

Reports concerning the influence of dams on river hydrology vary among researchers, interest groups and government agencies. These often contradicting statements may occur because changes in hydrology caused by dams are distinct for each dam and river watershed. The objective of this research was to use site specific techniques to determine if the 1967 installation of the Carlyle Dam, lower Kaskaskia River, Illinois, altered flood frequency and duration within the forested floodplain located below the dam. Results indicated a decrease in flood duration and frequency, and a decrease in annual flood frequency variation at a site 6.4 km below the dam. Pre‐dam versus post‐dam differences in flood frequency and duration at the site 32.2 km below the dam were related to climate rather than dam effects. Although dam impacts are a concern, this research shows that distance downstream from the dam and downstream tributary and watershed characteristics should be considered before assuming that the dam has changed hydrologic parameters for portions of rivers. This research also indicates that areas of the lower Kaskaskia River may still maintain hydrologic ecological integrity, and could be targeted for restoration and adaptive management purposes. Hydrologic modelling combined with river gage and on‐site well measurement techniques presented in this study could provide detailed flood frequency and duration information for land use, sociological and geomorphological questions in focus areas within river floodplains. Copyright © 2008 John Wiley & Sons, Ltd.     

Statistical tools for thermal regime characterization at segment river scale: Case study of the Ste‐Marguerite River

Suitable thermal fish habitats are constrained by both maximum and minimum temperature tolerances. A multivariate and geostatistical approach was developed to estimate stream thermal characteristics at the river segment scale. Data from 22 temperature‐monitoring stations during summer 2007 were used to estimate monthly maximum temperature as well as thermal characteristics such as the number of events, the cumulative degree–days and the associated duration over specific temperature thresholds of 19 and 21°C. The probability of exceeding these temperature thresholds has also been interpolated. The methodology relies on the construction of a multivariate space using physiographic and hydrological characteristics of gauging stations as inputs in a canonical correlation analysis (CCA). A geostatistical interpolation technique, ordinary kriging, was subsequently used to perform interpolation in the physiographical space constructed using CCA. Results from this study were obtained for thermal characteristics estimated into two different interpolation spaces: (1) a 7 metrics space, and (2) an 8 metrics space. Cross‐validation technique has been performed and satisfactory results were obtained. Kriging thermal characteristics (magnitude and duration) into the 7 metric space for a 19°C threshold exceedance leads to best results with Relative Root Mean Square Error (RRMSE) ranging between 9.66 and 15.08%. The study shows that kriging in a multivariate space is a promising tool for water resources managers, especially in cases where risk mapping for lethal or sub‐lethal temperature thresholds may be required for a specific fish species. Copyright © 2010 John Wiley & Sons, Ltd.     

掺MgO混凝土的宏细观试验研究

利用MgO膨胀剂的延迟微膨胀效应能显著提高大体积混凝土的力学性能,产生的预压应力还能有效提高大体积混凝土抵抗温度开裂的能力,但目前对其微观机理研究不多。采用宏观与微观相结合的方式,研究了不同活性指数、不同掺量的MgO混凝土的力学性能,利用SEM/EDS微观分析手段揭示了MgO对混凝土性能影响的作用机理。试验结果表明：MgO取代部分水泥掺入混凝土中,混凝土的力学性能降低;掺量为4%~5%时,活性指数为100s的MgO混凝土的膨胀率大于活性指数为50 s的MgO混凝土;MgO混凝土的膨胀特性与Ca,Si,Mg,Al等元素的分布情况有关,掺入的MgO将改变界面区Ca,Si,Mg元素的富集特性,Ca元素和Mg元素更易于在界面区富集,导致混凝土宏观力学性能的降低。     

基于MIDAS软件探讨施工工序对深基坑稳定性的影响

基于武汉地铁名都站深基坑工程与水文地质勘察资料,建立了三维工程地质仿真计算模型。依据名都站深基坑开挖支护方案,利用有限元软件MIDAS的摩尔-库仑本构模型,对武汉地铁名都站深基坑施工过程中,不同施工工序下每步开挖之后,基坑的变形情况做仿真模拟计算,并对比分析其对基坑稳定性的影响。结果表明：基坑围护结构的变形情况与施工工序有很大的关系,施工工序越合理,上部土体变形越小,反之越大。因此,在基坑工程的施工过程中,要注重施工步骤的划分与合理安排,从而保证基坑工程的安全。研究成果为以后武汉地区基坑工程的施工设计提供了值得借鉴的经验。