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1.
This paper presents the numerical simulation of a creeping slope in Upper Austria, using a visco-hypoplastic material law which describes the mechanical behavior of cohesive soils allowing for viscous effects, i.e. creep and relaxation. The method consists of: (1) determination of the parameters of the material law, based on laboratory tests on soil samples taken from the slope; (2) simulation of the laboratory tests with an element test program in which the used material law was implemented, in order to test whether the model holds for the soils studied; and (3) simulation of slope movements at different sections along the slope, assuming an infinite slope. The simulation results fit well with the field measurements. This demonstrates that despite strongly simplified boundary conditions and limited availability of subsurface data (e.g. density) the visco-hypoplastic law is a promising tool for predicting creep movements.  相似文献   

2.
Reservoir management requires periodic updates of the simulation models using the production data available over time. Traditionally, validation of reservoir models with production data is done using a history matching process. Uncertainties in the data, as well as in the model, lead to a nonunique history matching inverse problem. It has been shown that the ensemble Kalman filter (EnKF) is an adequate method for predicting the dynamics of the reservoir. The EnKF is a sequential Monte-Carlo approach that uses an ensemble of reservoir models. For realistic, large-scale applications, the ensemble size needs to be kept small due to computational inefficiency. Consequently, the error space is not well covered (poor cross-correlation matrix approximations) and the updated parameter field becomes scattered and loses important geological features (for example, the contact between high- and low-permeability values). The prior geological knowledge present in the initial time is not found anymore in the final updated parameter. We propose a new approach to overcome some of the EnKF limitations. This paper shows the specifications and results of the ensemble multiscale filter (EnMSF) for automatic history matching. EnMSF replaces, at each update time, the prior sample covariance with a multiscale tree. The global dependence is preserved via the parent–child relation in the tree (nodes at the adjacent scales). After constructing the tree, the Kalman update is performed. The properties of the EnMSF are presented here with a 2D, two-phase (oil and water) small twin experiment, and the results are compared to the EnKF. The advantages of using EnMSF are localization in space and scale, adaptability to prior information, and efficiency in case many measurements are available. These advantages make the EnMSF a practical tool for many data assimilation problems.  相似文献   

3.
在现有的碎屑沉积地质体构型分级方案基础上,充分考虑自然界中河流沉积演化规律以及海上油田的资料基础与经济开发尺度等因素,遵循地质体分级原则与依据,建立了海上油田河流相复合砂体构型分级方案。从地质成因、主控因素、时空规模等方面系统阐述了河流相复合砂体13级构型单元的基本特征,并解析其与相关沉积地质体级次的关联性。与现有的储层构型分级的差异主要在于新增了“复合点坝”级次,复合点坝是多期残存点坝以复合体形式叠置而成的沉积单元,该级次是储层构型理论、海上油田资料分辨能力与经济开发尺度三者的契合点,是海上油田“地震导向、井震联合”构型研究思路的良好实践。河流相复合砂体构型分级对于指导海上油气开发具有一定的优势。  相似文献   

4.
李珍福  李学军 《铀矿地质》1994,10(6):360-366
壤中蜡样芽孢杆菌找矿法是微生物地球化学探矿方法之一。本文叙述了蜡样芽孢杆菌法的找矿原理、野外工作方法、室内测量技术、野外初步试验的地质效果以及测量中应注意的若干问题。在已知隐伏金矿床(点)和铀矿床(点)上测得了明显的蜡样芽孢杆菌计数异常,并在460铀(钼)矿床外围的铀矿化远景地段进行了试验,地质效果较为理想。  相似文献   

5.
In this paper, there is presented an elastoplastic constitutive model to predict sandy soils behavior under monotonic and cyclic loadings. This model is based on an existing model (Cambou‐Jafari‐Sidoroff) that takes into account deviatoric and isotropic mechanisms of plasticity. The flow rule used in the deviatoric mechanism is non‐associated and a mixed hardening law controls the evolution of the yield surface. In this research the critical state surface and history surface, which separates the virgin and cyclic states in stress space, are defined. Kinematic hardening modulus and stress–dilatancy law for monotonic and cyclic loadings are effectively modified. With taking hardening modulus as a function of deviatoric and volumetric plastic strain and with defining the history surface and stress reversal, the model has the ability to predict the sandy soils' behavior. All of the model parameters have clear physical meanings and can be determined from usual laboratory tests. In order to validate the model, the results of homogeneous tests on Hostun and Toyoura sands are used. The results of validation show a good capability of the proposed model. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

6.
蒋明镜  周卫  刘静德  李涛 《岩土力学》2016,37(12):3347-3355
在岩土破损力学基础上,基于微观破损机制,提出了考虑各向异性的结构性砂土本构理论。采用Lade-Duncan强度准则考虑中主应力对抗剪强度的影响;采用考虑颗粒排列组构的各向异性状态变量A反映各向异性对土体强度和变形的影响;通过相似扩大重塑土的屈服面反映结构性对土性的影响;通过引入非相关联流动法则考虑各向异性和结构性对土体塑性变形的影响。同时,将基于微观力学机制的损伤演化规律引入结构性土的硬化规律;该硬化规律同时考虑了塑性体积应变和剪切应变对各向异性结构性土强度的影响。然后将该模型用于模拟室内三轴压缩试验,初步验证了该模型的合理性和适用性。  相似文献   

7.
In the past ten years, time-lapse (4D) seismic has evolved as a standard way of monitoring reservoir performance. The method is now being used as good reservoir management practice to provide evidence of saturation changes within the reservoir at field scale. 4D provides a new piece of data describing the dynamic behavior of the reservoir fluids between the wells, often limited to small scale monitoring at the borehole scale. Thus, it provides sophisticated techniques for reservoir monitoring and management relying on the integration of geological models, static and dynamic properties of the reservoir rock, and detailed production and pressure field data.While 4D seismic data has been very successful in monitoring hydrocarbon production from clastic reservoirs, this work has focused on implementing 4D time lapse to monitor saturation changes in carbonate reservoirs and it’s capability to be used as enhanced oil recovery (EOR) tool that can help in enhancing the recovery factor for the filed and help to locate new drilling to sweep more oil out of the reservoir and locate the by-pass oil.The principal goal of this research was to detect the maximum change in seismic attributes (amplitude, acoustic impedance, travel time) that could occur as a result of oil production, water and gas injection in carbonate reservoirs by using time-lapse 4D seismic.  相似文献   

8.
通过矿田一些地质地球化学等成因依据的研究和长坡矿热水喷口的发现,提出区域地球化学场的存在,中元古界—下古生界原始矿源层的形成,泥盆纪海底火山—热水成矿作用、华力西—印支期大广地区石油的形成—迁移—聚积过程形成富含金属成矿物质的油气田,燕山期岩浆热液叠加改造成矿作用以及燕山期构造—岩浆作用破坏富含金属成矿物质的油气田而成矿等—系列地质作用在大厂地区地质历史上有机组合,形成大厂超大型矿床,而泥盆纪火山及海底热水作用、燕山期构造—岩浆作用则是主导成矿作用.  相似文献   

9.
The soil heave over time associated with a leak in a hot-water line beneath a floor slab of a lightly loaded structure constructed on a natural unsaturated expansive soil in Regina of Saskatchewan, Canada is modelled in this paper using the Modulus of Elasticity Based Method (MEBM). The case history arises from the studies that were initiated by the Prairie Regional Station of the Division of Building Research, National Research Council in 1960s as a part of a comprehensive field study program to investigate the problems associated with construction in/on an expansive soil in the Regina area. There is a good comparison between the results from the MEBM and the published data of measurements and estimations of soil heave over time. The encouraging results of this study suggest that the MEBM is a simple and promising approach for use in conventional engineering practice by geotechnical engineers for estimation of the heave over time of expansive soils.  相似文献   

10.
The fundamental problem of geology is scale. Geological length scales range from angstroms for atoms to thousands of kilometres for planets. Geological processes are often very slow (and geological events so very infrequent). Since the beginning of our discipline, it has been the business of geologists to integrate observations at a variety of length and time scales to answer questions about Earth's history and to make predictions about its future. While this may sound like one of the most academic of pursuits, multi‐billion dollar decisions are routinely made by governments and the largest multi‐national corporations on the basis of geological studies that, for example, model groundwater or petroleum occurrence.  相似文献   

11.
随着21世纪人类城市化建设的发展,城市环境地质研究成为水工环地质研究领域的一个重要组成部分,城市建设中的最主要问题是水资源问题和环境地质问题。城市水资源问题有:城市后备水源地的研究,以及应急水资源地和地下水库的研究。城市环境地质问题主要包括:(1)围绕城市建设和发展的一般性资源、地质环境问题;(2)城市地质作用产生的地质环境问题;(3)城市人口密集区及工业区的土壤和水体有机污染问题。解决城市环境地质问题的关键是对地下空间地层岩性及构造条件的研究,通过这些基础条件研究分析城市地质环境和地下水资源问题。可视化研究技术通过对城市地质体在地下空间的相对位置、形态、物化特征等三维构模处理,使这些城市赖以存在的地质基础条件可为非专业的决策层所理解,并在城市发展的规划中体现这些大自然所赋予人类的地下空间资源的价值。应用三维可视化技术对城市环境地质研究是一个全新的研究领域,目前尚没有系统完整的应用先例。三维可视化技术将在城市化环境地质研究中,开拓一个崭新的环境地质研究时代,成为城市环境地质研究的发展方向。  相似文献   

12.
膨胀土工程地质特性研究进展   总被引:1,自引:0,他引:1  
根据近年来国内外学者围绕膨胀土工程地质特性取得的研究成果,着重从胀缩性、裂隙性、超固结性、强度、渗透性、微观结构及工程处治技术等几个方面总结了该课题的研究现状及进展,得到如下认识:(1)胀缩性主要取决于强亲水性黏土矿物含量、水/力边界条件及初始状态,在干湿循环条件下具有不可逆性,关于胀缩机理学界存在不同的观点;(2)裂隙性是膨胀土区别于一般土体的显著特征之一,裂隙的存在会极大破坏土体的整体性,弱化力学性质,是许多工程地质问题的直接或间接原因,裂隙形成过程与膨胀土矿物成分、微观结构和干燥过程中的内应力发育状态有关;(3)超固结性使膨胀土具有较大结构强度和水平应力,易在开挖过程中引起较强的卸荷效应,是促进边坡失稳的重要因素;(4)膨胀土的强度随干湿循环次数增加而逐渐降低,并最终趋于稳定,其中裂隙发育和土结构调整在此过程中起关键作用;(5)渗透性在很大程度上受裂隙的控制,但目前关于两者之间的定量关系还缺少系统研究;(6)微观结构反应了膨胀土的形成条件和应力历史,是决定其宏观物理力学性质的主要因素,开展微观结构研究是掌握膨胀土宏观性质本质规律的重要途径。在工程处治技术上,本文重点介绍了近些年发展起来的膨胀土路堤物理处治技术和路堑边坡柔性支护技术。最后,针对该课题的研究现状,笔者提出了今后的研究重点和方向,主要包括胀缩性和力学性质的各向异性、裂隙形成的力学机理、裂隙形态特征与工程地质特性之间的定量关系、宏-微观力学模型耦合问题及多场耦合作用下膨胀土工程性质响应特征等。  相似文献   

13.
The theoretical evaluation of the scale effect in dispersed soils is considered in the engineering–geological study of various physical and physicomechanical properties that depend on the structural inhomogeneity of a soil. Concepts and new quantitative indicators are proposed to evaluate the manifestation of the scale effect in dispersed soils in relation to physical and physicomechanical properties. The classification of structural heterogeneities in dispersed soils that affect the scale effect in them has been developed. A method for analyzing the scale effect in dispersed soils is described on the basis of the superposition principle. A theoretical model of recording the scale effect in dispersed soils is substantiated in engineering–geological evaluation of various physical and physicomechanical properties.  相似文献   

14.
15.
构造地质成因分析,在油气田开发中具有十分重要的作用。文章从国内外研究现状入手,在文献调研基础上详细对 比了油气田开发中构造地质成因分析的优缺点。总结了构造地质成因分析研究内容:(1) 通过构造演化历史分析和地应力 场等研究,确定断裂体系构造地质成因。(2) 井震结合开展精细的构造解释,分析构造地质成因。(3) 对构造地质成因研 究方法进行探索和改进。(4) 综合动静态资料,开展储层地质成因分析。(5) 与沉积相研究和成岩作用研究等紧密结合。 (6) 加强地质成因分析成果应用,为油气田开发提供基础。(7) 裂缝表征和建模。(8) 微构造地质成因分析。油气田开发 中构造地质成因分析的方法主要包括:基础地质研究、野外露头观察描述、岩心观察和描述、镜下薄片观察、物理模拟、 各种测井解释、地震解释、各种分析测试统计、地质建模、动态监测和生产动态分析方法等。结合研究实践,对每一种方 法的优缺点进行分析。在此基础上,指出了油气田开发中构造地质成因分析存在的8方面主要问题和发展趋势。  相似文献   

16.
在植被稠密覆盖区,野外岩性、地层可见度很低,已成为地质调查和找矿的瓶颈。长期以来,遥感界一直在孜孜不倦地探索应用廉价多光谱TM数据在这些地区进行区域地质填图和开展找矿方法的研究。本研究选择湘西贫困山区作为实验区,首先从植物微量元素的生理功能入手,找出不同植被微量元素与光谱响应之间的关系,然后综合利用区域岩石地球化学数据、土壤地球化学数据、植被叶片成像光谱数据和生化成份分析数据等,建立成份、光谱与波段的关联进行合适的TM影像波段选择,最后应用遥感数据弱信息提取方法(MPH技术)对植被覆盖区进行快速的大面积岩性划分和异常信息提取,取得较好的地质填图和找矿效果。  相似文献   

17.
综合运用油源对比、断裂-砂体研究、油藏充注史分析等方法,对东营凹陷梁家楼地区输导体系进行了研究,认为梁家楼油田下第三系沙三中、下亚段及沙四上亚段有效烃源岩主要通过同生断层与沙三上亚段储层连通,垂向运移是本地区油气主要运移方式,断层是输导体系的主要组成部分,断层活动期次控制油气运移期次,有效烃源岩分布和断裂活动方式共同决定了油气运移模式,进而提出有效输导体系概念是油气运移路径空间有限性及时间有效性的统一表现。  相似文献   

18.
三维地质建模及油藏数值模拟一体化剩余油分布规律研究   总被引:1,自引:0,他引:1  
剩余油分布规律研究一直是中后期油田开发的研究重点和难点,研究方法也多种多样.针对马岭油田中一区的开发特点,采用三维地质建模和油藏数值模拟一体化技术研究思路,在构造特征研究、精细地层对比、沉积相研究和流动单元研究的基础上,建立了中一区延长组到富县组的三维立体地质模型,从而为油藏数值模拟提供了初始静态地质模型.在历史拟合的基础上通过精细油藏模拟方法进行了油藏剩余油分布模拟计算,并结合沉积相和流动单元分析了剩余油分布规律,从而为油田下步方案调整提供了挖潜方向.  相似文献   

19.
土体颗粒破碎研究进展   总被引:4,自引:7,他引:4  
在打入桩的桩端以及大型土石坝、海洋平台等的地基中常常会出现高应力区。在这些高应力区中,作为地基的粒状土的颗粒会发生不同程度的破碎。对高应力水平下粒状土体的破碎特性进行深入研究有助于解决这一类型的岩土工程问题。因此近年来土体颗粒破碎逐渐引起人们的重视。本文对土体颗粒破碎研究现状进行了详尽的阐述,并指出研究中存在的问题及今后研究发展方向。  相似文献   

20.
模式识别技术在油气化探中的应用   总被引:3,自引:0,他引:3  
本文将模式识别技术应用于油气化探,给出了方法的逻辑框图,剖析了一个典型实例,其结果说明运用模式识别方法获得地球化学场的基本结构及其变异特征,反映了地球化学场的变化规律。结合地质条件提炼出的成藏模式能为预测油气藏指明方向。  相似文献   

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