Upscaling of elastic properties for large scale geomechanical simulations     

F. Chalon  M. Mainguy  P. Longuemare  P. Lemonnier 《国际地质力学数值与分析法杂志》2004,28(11):1105-1119

Large scale geomechanical simulations are being increasingly used to model the compaction of stress dependent reservoirs, predict the long term integrity of under‐ground radioactive waste disposals, and analyse the viability of hot‐dry rock geothermal sites. These large scale simulations require the definition of homogenous mechanical properties for each geomechanical cell whereas the rock properties are expected to vary at a smaller scale. Therefore, this paper proposes a new methodology that makes possible to define the equivalent mechanical properties of the geomechanical cells using the fine scale information given in the geological model. This methodology is implemented on a synthetic reservoir case and two upscaling procedures providing the effective elastic properties of the Hooke's law are tested. The first upscaling procedure is an analytical method for perfectly stratified rock mass, whereas the second procedure computes lower and upper bounds of the equivalent properties with no assumption on the small scale heterogeneity distribution. Both procedures are applied to one geomechanical cell extracted from the reservoir structure. The results show that the analytical and numerical upscaling procedures provide accurate estimations of the effective parameters. Furthermore, a large scale simulation using the homogenized properties of each geomechanical cell calculated with the analytical method demonstrates that the overall behaviour of the reservoir structure is well reproduced for two different loading cases. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

塔里木盆地塔中1井藻纹层白云岩与竹叶状白云岩成因——基于岩石学、元素与同位素地球化学的厘定   总被引：1，自引：0，他引：1  

陈永权  周新源  赵葵东  杨文静  董晨阳  朱长见 《地质学报》2008,82(6):826-834

塔里木盆地寒武系—奥陶系底部发育了大量的白云岩, 白云岩中赋存丰富的油气资源, 但是由于塔里木盆地白云岩研究基础薄弱,限制了塔里木盆地白云岩型油气藏的勘探。本文选择塔中地区塔中1井下奥陶统藻纹层白云岩与夹层竹叶状白云岩作为对象,应用岩石学与地球化学方法对其成因问题进行了研究。藻纹层白云岩与夹层竹叶状白云岩的宏观构造与微观结构指示其可能形成于高能的潮坪环境;低有序度值（0.6）与塔北地区中寒武统阿瓦塔格组潮坪同沉积白云岩(有序度值0.61)特点一致,指示该白云岩结晶速率较快;同时,高Fe、Mn含量与低U、Mo含量也与氧化环境的潮坪相一致。藻纹层白云岩与夹层竹叶状白云岩δ18O值非常集中, 变化在-7.4‰～-5.8‰;87Sr/86Sr组成变化很小,在0.709015～0.709276之间,与前人报道的晚寒武世－早奥陶世海水同位素特征一致,同时白云岩的稀土元素配分模式也与下奥陶统泥晶灰岩一致,指示了白云岩的沉积/成岩物质来源于蒸发海水;白云岩δ13C值变化从-2.5‰～+1.6‰,并有着随深度增加而升高的变化规律,可能指示了古海洋的碳同位素氧化。藻纹层白云岩与夹层竹叶状白云岩的构造特点具有原生沉积特征,同时白云岩CaO与MgO含量的正相关关系也支持该白云岩原生沉积特点。因此,塔里木盆地塔中1井钻遇的下奥陶统藻纹层白云岩与夹层竹叶状白云岩为潮坪环境下,从蒸发海水中快速沉积形成的。  相似文献   

Associations between Atlantic cod (Gadus morhua) and hydrographic variables: implications for the management of the 4VsW cod stock     

Smith  Stephen J.; Page  Fred H. 《ICES Journal of Marine Science》1996,53(3):597-614

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分层流体中内孤立波在潜浮式竖直薄板上透射和反射   总被引：2，自引：0，他引：2  

魏岗  尤云祥  缪国平  苏晓冰 《海洋工程》2007,25(1):1-8

采用边缘层理论研究了两层流体系统中内孤立波在潜浮式竖直薄板上的透射和反射问题,提出了非线性演化方程的“初值”条件,分析了内孤立波与薄板非线性相互作用的效应。研究表明:流体层的密度比以及薄板伸入上下层的深度对于反射和透射波结构具有显著的影响,薄板伸入下层越深、密度差越小,则薄板阻碍孤立波透射的效率越高;透射波通常演化为单峰孤立波和迅速衰减的尾波,反射波演化为缓慢衰减的尾波列;对于具有小密度差的跃层结构,内孤立波在潜浮式竖直薄板上的透射及其演化近乎是无障碍的。  相似文献   

分层海洋的内孤立波     

徐肇廷 《中国海洋大学学报(自然科学版)》1989,(3)

本文从流体力学基本方程组出发,在非地转条件下导得了分层海洋的内孤立波方程—Kbv和mKdv方程,证实了在非地转条件下,一类海洋非线性波动是可以严格满足内孤立波方程的。在地转条件下采用f平面近似导出了KdV方程的演化形式一有源KdV方程,地转的影响含于源项中。由初步的分析得出,f对KdV方程的影响是微弱的。由已得的KdV和mKdV方程的解可知,内孤立波与线性波有着本质差别。  相似文献   

Internal wave eigenmodes and their weak nonlinear resonant interaction in a nonlinearly stratified fluid—A preliminary theoretical and experimental study     

Wang Yiming  Xu Zhaoting 《中国海洋湖沼学报》1992,10(1):44-56

A preliminary theoretical and experimental study was conducted on internal wave modes and their weak nonlinear resonant interaction in a nonlinearly stratified fluid. An asymptotical solution of the modes and a dispersion relation of internal waves in a stratified fluid with density profile similar to that in our experiment were obtained theoretically. The resonant-interaction mechanism to 2nd order approximation is also discussed. The resonant interaction of the 3rd and 4th mode internal waves excited by the unstable 1st mode wave is analyzed on the basis of data obtained by conductivity probes. The resonant-interaction condition, i.e., ,k ₁+k ₃+k ₄=0, is examined. It is shown that the resonant instability increases with pycnocline thickness and wave maker driving frequency. This work is supported by the National Natural Science Foundation of China.  相似文献   

层状岩质边坡的屈曲破坏分析   总被引：7，自引：2，他引：7  

黄洪波  符文熹  尚岳全  聂德新 《山地学报》2003,21(1):96-100

本文根据多层层状结构岩质边坡的屈曲破坏模式，建立了相应的力学模型，从理论上对这种形式的破坏机理进行了研究，得出了相应力学模型的挠曲曲线的理论解。对具体工程实例的应用表明，本文的研究成果不仅能解决具体工程问题，而且有助于深入理解该类边坡的屈曲破坏机理。  相似文献   

静力触探中土层界面效应试验研究   总被引：2，自引：2，他引：2  

陈维家  汪火旺 《水文地质工程地质》2003,30(2):25-27

根据成层土模型试验结果,对静力触探中土层面效应进行试验研究和机理分析,取得了成层土界面效应的规律性,为利用静力触探划分土层提供了理论和实践依据。  相似文献   

U–Pb zircon chronostratigraphy of early-Pliocene ignimbrites from La Pacana, north Chile: implications for the formation of stratified magma chambers     

Axel K Schmitt  Jan M Lindsay  Shan de Silva  Robert B Trumbull 《Journal of Volcanology and Geothermal Research》2003,120(1-2):43-53

High spatial resolution U–Pb dates of zircons from two consanguineous ignimbrites of contrasting composition, the high-silica rhyolitic Toconao and the overlying dacitic Atana ignimbrites, erupted from La Pacana caldera, north Chile, are presented in this study. Zircons from Atana and Toconao pumice clasts yield apparent ²³⁸U/²⁰⁶Pb ages of 4.11±0.20 Ma and 4.65±0.13 Ma (2σ), respectively. These data combined with previously published geochemical and stratigraphic data, reveal that the two ignimbrites were erupted from a stratified magma chamber. The Atana zircon U–Pb ages closely agree with the eruption age of Atana previously determined by K–Ar dating (4.0±0.1 Ma) and do not support long (>1 Ma) residence times. Xenocrystic zircons were found only in the Toconao bulk ignimbrite, which were probably entrained during eruption and transport. Apparent ²³⁸U/²⁰⁶Pb zircon ages of 13 Ma in these xenocrysts provide the first evidence that the onset of felsic magmatism within the Altiplano–Puna ignimbrite province occurred approximately 3 Myr earlier than previously documented.  相似文献   

上震旦统灯影组中非叠层石生态系兰细菌白云岩   总被引：10，自引：1，他引：10  

方少仙  侯方浩等 《沉积学报》2003,21(1):96-105

上震旦统灯影组 2段和 3段是四川盆地主要天然气储层之一。在浅色白云岩地层中富含炭化的黑色非叠层石生态系兰细菌白云岩。它既可发育于沉积期和胶结作用期 ,也可发育于表生成岩作用期。沉积期发育的非叠层石生态系兰细菌白云岩呈纹层状产出或围绕颗粒的四周生长。这类兰细菌白云岩的单层厚度从 1mm到 >10 cm不等 ,其总厚度约占灯影组 2段和 3段的 1/ 10左右 ,有时也呈不连续的黑色小点发育于白色叠层石生态系兰细菌白云岩的叠层石、层纹石中。胶结作用期 ,二或三个世代亮晶胶结物交替发育“充填”孔隙。表生成岩作用期 ,黑色的兰细菌主要呈多世代的线状纹层与白色纤维状白云石组成多世代的间互纹层充填在岩溶溶洞、溶沟以及扩溶的裂隙中。非叠层石生态系兰细菌主要形态有球形、椭球形和棒形 ,偶有蘑菇形及其它形状。群体呈现为串珠状、草丛状、分叉树枝状和类似于火山喷发状等等。群体的古生态表现为向上生长、围绕颗粒向四周发散生长、粘结颗粒 ,或向原生粒间孔隙、次生溶洞、溶沟中心向心生长。对现代兰细菌的降解实验佐证所讨论的非叠层石生态系兰细菌是灯影组中烃源岩之一。  相似文献