从钠溪气田看阳新统裂缝型气藏分布复杂性     

崔世南  耿文志 《矿物岩石》1995,(4)

本文以纳溪气田的实际资料，特别是纳６井裂缝系统的典型资料，裂缝系统在纵横向上的分布具明显的方向性和系统中流体分布异常，剖析川南地区二叠系阳新统裂缝型气藏分布的复杂性，为裂缝型气藏的勘探提供借鉴。  相似文献   

单个粘土体裂缝中水流规律的研究   总被引：2，自引：0，他引：2       下载免费PDF全文

葛中华  范炳恒 《地质学报》1993,67(2):159-167

通过模型实验,研究粘土体裂缝中的水流规律,提出了临界水位上升速度的概念。水位上升速度大于临界值时,裂缝中水流量增加,反之则减少。裂缝水流量与水位不呈正比关系。指出粘土裂缝中最大水流量要比相同条件下基岩裂缝水流量小30—40倍。随着水流运动的延续,水流量将逐渐变小。在水流作用下,粘土裂缝宽度将变窄3.0—4.0cm,裂缝深度也大幅度变浅到裂缝水深的50％以上。  相似文献   

Hydrofracture mechanisms in rock during pressure grouting     

H. Y. Wong  I. W. Farmer 《Rock Mechanics and Rock Engineering》1973,5(1):21-41

Summary Hydrofracture Mechanisms in Rock During Pressure Grouting. The paper examines the basic meachnisms controlling the initiation of fractures in rocks and layered soils during pressure grouting, and their subsequent propagation into the ground mass. Previous analyses of fracture initiation have tended to concentrate on simplified models in which the ground is treated as an impervious elastic or Mohr-Coulomb continuum. The present method allows for the porous or fissured nature of the ground by considering the effect of seepage forces induced by the pore pressure gradient. The effect is quantified by use of a parameterN such that the ratio of fluid force used in expanding the injection hole, to that used in forcing fluid through void spaces, isN to (1—N).Analysis of hydrofracture propagation is based on stress analysis of a borehole in an elastic continuum, the propagating fracture zone around the borehole being represented as a non-elastic material governed by the Mohr-Coulomb failure criterion. This is supplemented by an energy approach which equates the energy supplied to the ground from the injection pump, with the energy stored in the ground and the energy necessary to fracture it.

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Zusammenfassung Brucherscheinungen im Fels bei Verprearbeiten. In der Arbeit wird der grundlegende Mechanismus untersucht, welcher bei Verpreßarbeiten in Fels und geschichtetem Boden zur Einleitung und Ausbreitung von Brüchen führt. Frühere Untersuchungen des Bruchbeginns stützten sich im wesentlichen auf vereinfachte Modelle, in denen der Untergrund als undurchlässiges Kontinuum angesehen wird, das entweder elastisch ist oder der Mohr-Coulombschen Bruchbedingung genügt. Die neue Methode berücksichtigt dagegen eine Porosität oder Klüftung des Untergrundes durch Ansatz der vom strömenden Medium auf das Gebirge ausgeübten Belastung. Diese Belastung wird aufgeteilt in einen Druckverlust an der Bohrlochwand (gleich ParameterN mal Verpreßdruck) und die entsprechende, über den gesamten durchströmten Bereich verteilte Belastung.Die Untersuchung der Bruchausbreitung geht von der Spannungsermittlung um ein Bohrloch in einem elastischen Kontinuum aus, wobei in der sich ausbreitenden Bruchzone um das Bohrloch herum nichtelastisches Material angenommen wird, das dem Mohr-Coulombschen Bruchkriterium genügt. Zur Ergänzung dient eine Energie-Betrachtung, bei der die von der Injektionspumpe abgegebene Energie gleichgesetzt wird der im Untergrund gespeicherten Energie und der aufgewendeten Brucharbeit.

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Résumé Les mécanismes de la fracturation hydraulique dans les roches pendant les injections sous pression. Le mémoire examine les mécanismes fondamentaux qui gouvernent l'initiation des ruptures dans les roches et les sols stratifiés, au cours des injections et leur propagation dans les massifs. Les analyses antérieures de l'initiation de la rupture, se sont concentrées sur des modèles simplifiés où l'on considérait la roche comme un milieu élastique et imperméable, ou comme un milieu de Mohr-Coulomb. La présente méthode admet que le massif est poreux ou fissuré, en considérant l'action des forces de percolation engendrées par le gradient de pression interstitielle. Cette action est quantifiée par un paramètreN, tel que le rapport de la force du liquide employée à dilater le forage d'injection, à celle employée pour forcer le coulis à travers les vides soitN/(1—N). L'analyse de la propagation des ruptures se base sur l'analyse des contraintes autour d'un forage dans un milieu élastique, alors que la zone de la rupture qui se propage autour du forage est représentée par un milieu non-élastique admettant le critère de rupture de Mohr-Coulomb. Cette analyse est complétée par une approche énergétique, où l'énergie qui est fournie au massif par la pompe d'injection est égalée à l'énergie emmagasinée dans la roche et à l'énergie de rupture.

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Nomenclature A area of new cracks created per unit volume of time t - E total work done by injection fluid - E _i irrecoverable component of energy - E _{i c} work done in fracturing rock or soil - E _{i l} work done to overcome various frictional forces in grouting system - E _{i p} work done to cause plastic deformation of fractured zone - E _{i s} work done to overcome shear strength of fluid during flow - E _{i v} work done to overcome frictional drag between fluid and rock in soil surfaces during flow - E _r recoverable component of energy - E _{r f} elastic strain energy stored in fluid - E _{r s} elastic strain energy stored in rock or soil - h height of overburden - i j 1, 2, 3 - K ₀ coefficient of horizontal earth pressure - k permeability of ground to grout - L length of cylindrical grout source - n rock or soil porosity - p average fluid pressure between timet and (t + t) - p ₀ injection pressure - R radius of grout front - r radial distance from borehole axis - r ₀ radius of borehole - r ₁ radius of fractured zone - S specific surface area of rock or soil - S _T tensile strength of rock or soil - t time - u grout seepage velocity - V volume of grout injected - v volumetric strain - specific surface energy of rock - bulk density of rock or soil - _{i j} ^e elastic strain increment tensor - _{i j} plastic strain increment tensor - v Poisson's ratio - _{i j} average stress tensor in the ground during timet and (t + t) - _R , _T, _Z radial, tangential and vertical stresses induced by grouting - _r , _t , _z radial, tangential and vertical stress around borehole before grouting - grout shear strength - angle of internal friction of rock or soil With 7 Figures  相似文献   

X-Ray Interferometry     

Webster Cash 《Experimental Astronomy》2003,16(2):91-136

For the astronomer, X-ray interferometry is the theory and practice of building dilute aperture telescopes for studying celestial X-ray sources. The short wavelengths and high surface brightness of X-ray sources will make the eventual scientific payoff very high, with direct imaging of the event horizons of black holes as the centerpiece. In this article, we review the history of X-ray interferometry and discuss the recent technical developments toward astronomical applications. We present several mission concepts and show they are achievable with todays technology.  相似文献   

Monitoring of fault healing after the 1999 Kocaeli, Turkey, earthquake     

Keiichi Tadokoro  Masataka Ando  Şerif Bariş  Kin'ya Nishigami  Mamoru Nakamura  S. Balamir Ücer  Akihiko Ito  Yoshimori Honkura  A. Mete Işikara 《Journal of Seismology》2002,6(3):411-417

The North Anatolian fault zone that ruptured during the mainshock of theM 7.4 Kocaeli (Izmit) earthquake of 17 August 1999 has beenmonitored using S wave splitting, in order to test a hypothesisproposed by Tadokoro et al. (1999). This idea is based on the observationof the M 7.2 1995 Hyogo-ken Nanbu (Kobe) earthquake, Japan.After the Hyogo-ken Nanbu earthquake, a temporal change was detectedin the direction of faster shear wave polarization in 2–3 years after the mainshock (Tadokoro, 1999). Four seismic stations were installed within andnear the fault zone at Kizanlik where the fault offset was 1.5 m, about80 km to the east of the epicenter of the Kocaeli earthquake. Theobservation period was from August 30 to October 27, 1999. Preliminaryresult shows that the average directions of faster shear wave polarization attwo stations were roughly parallel to the fault strike. We expect that thedirection of faster shear wave polarization will change to the same directionas the regional tectonic stress reflecting fault healing process. We havealready carried out a repeated aftershock observation at the same site in2000 for monitoring the fault healing process.  相似文献   

A new scheme for numerical modelling of flow and transport processes in 3D fractured porous media     

Andrés Peratta  Viktor Popov 《Advances in water resources》2006

The objective of this work is to develop a new numerical approach for the three-dimensional modelling of flow and transient solute transport in fractured porous media which would provide an accurate and efficient treatment of 3D complex geometries and inhomogeneities. For this reason, and in order to eliminate as much as possible the number of degrees of freedom, the fracture network, fractures and their intersections, are solved with a coupled 2D–1D model while the porous matrix is solved independently with a 3D model. The interaction between both models is accounted for by a coupling iterative technique. In this way it is possible to improve efficiency and reduce CPU usage by avoiding 3D mesh refinements of the fractures. The approach is based on the discrete-fracture model in which the exact geometry and location of each fracture in the network must be provided as an input. The formulation is based on a multidimensional coupling of the boundary element method-multidomain (BEM-MD) scheme for the flow and boundary element dual reciprocity method-multidomain (BE-DRM-MD) scheme for the transport. Accurate results and high efficiency have been obtained and are reported in this paper.  相似文献   

EH-4电导率成像系统的特点及其在金属矿勘探中的应用   总被引：10，自引：0，他引：10  

孟贵祥  兰险 《矿床地质》2006,25(1):36-42

EH-4电导率成像系统是一种混场源频率域电磁观测系统,具有轻便、高效、勘探深度大、分辨率高的特点。通过在块状硫化物铜矿、斑岩铜矿已知矿区的试验研究,证实EH-4系统在这两种矿床类型的隐伏-半隐伏金属矿勘探中有较好的找矿效果。  相似文献   

成像光谱技术在典型蚀变矿物识别和填图中的应用   总被引：6，自引：1，他引：6       下载免费PDF全文

刘圣伟甘甫平  闫柏琨杨苏明王润生  王青华唐攀科 《中国地质》2006,33(1):178-186

成像光谱矿物识别和填图技术是中国国土资源调查和监测重点发展的高新技术之一。笔者以国土资源调查应用为主要目标,研究了成像光谱矿物识别和矿物填图技术实用化中的一些关键技术问题。分析了白云母和绿泥石两种重要蚀变矿物的光谱特征及光谱变异特征;以新疆东天山黄山地区的HyMap数据为例,对目前已较为系统化的成像光谱识别技术(如MNF变换、像元纯度指数PPI和N维可视化端元识别NDVI)在典型蚀变矿物识别和填图中的应用进行介绍。  相似文献   

成像光谱数据特征选择及小麦品种识别实验研究   总被引：6，自引：0，他引：6  

王长耀  刘正军  颜春燕 《遥感学报》2006,10(2):249-255

针对河北栾城获得的MAIS成像光谱仪数据用于小麦品种识别进行了特征选择和分类研究。利用遗传算法以JM距离为准则并结合实验区小麦的生物物理特性，进行了最佳波段选择；利用Fuzzy—Anmap分类器及选出的最佳波段对成像光谱数据进行了分类，区分出了4种小麦品种，小麦的总体分类精度超过97％。  相似文献   

云南思茅—中甸地震剖面的地壳结构   总被引：7，自引：7，他引：7       下载免费PDF全文

张智  赵兵  张晰  刘财 《地球物理学报》2006,49(5):1377-1384

云南思茅—中甸宽角反射/折射地震剖面切割松潘—甘孜、扬子和华南三个构造单元的部分区域. 我们利用初至波和壳内反射波走时层析成像获得地壳纵波速度结构. 在获得新的地壳速度结构模型基础上，利用地震散射成像思想和低叠加次数的叠前深度偏移方法重建了研究区的地壳、上地幔反射结构. 综合分析研究区地壳P波速度模型和壳内地震反射剖面发现：沿测线从北至南地壳厚度从约50 km减薄至35 km左右，地壳厚度的减薄量主要体现在下地壳，剖面北段下地壳厚度约为30 km，剖面南段下地壳厚度仅为15 km左右；上地幔顶部局部位置P波速度值偏低，一般为76～78 km/s，反映出云南地区是典型的构造活动区的特点.剖面沿线地壳内地震反射发育，其中莫霍强反射出现在景云桥下方；在景云桥弧形断裂带8～10 km深处出现宽约50 km的强反射带.  相似文献