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1.
断层带结构和内部流体流动特性是水文地质研究领域的难点问题。石油地质领域,在油气运移与成藏方向已形成较成熟的断层封闭性定量评价技术手段。相比较,断裂的水文地质性质研究尚停留在断裂的力学性质对断层导水、阻水特性的定性评价阶段,尚未详细开展断裂带结构、渗透性各向异性等方面的研究工作。文章梳理总结国外断裂带水文地质性质研究中关于结构组成、断裂带演化、渗透率影响因素等方面的研究成果,引入断裂带渗透率结构模型,并以中国北方岩溶区碳酸盐岩与碎屑岩互层含水岩组为例,构建断裂带水文地质结构模型。断裂带研究尺度和精度不同、断裂带发育部位不同,导致其结构及水文地质性质亦不相同,如何建立起精确、典型的断裂带水文地质结构模型,需要各领域数据共享及多学科融合共同开展研究工作。   相似文献   

2.
先前的研究多考虑断层封堵和开启的2种极端状态,近来的研究认为,在多数情况下断层处于2种之间的状态,只有在静止期具有封闭能力的断层,才有可能对油气起封堵作用。分析断层对流体运移的影响,需要分析断层在演化过程中的内部结构特征。断层可以划分出破碎带、诱导裂缝带和围岩3部分,断层岩和伴生裂缝构成破碎带的主体部分。常见的断层岩包括断层角砾岩、断层泥和部分碎裂岩,它们充填在断层裂缝空间中,断层内部结构受断层形成时的构造应力性质、断层活动强度和围岩岩性因素的控制。从动态角度看,随着断距增加,断层活动伴随着裂缝的发育和岩石的破碎混杂,可用泥质源岩层厚度和断距的比值来划分不同的发育阶段。断层活动期为油气运移通道,在静止时表现出差异性的封闭,通常用断层渗透率和排替压力2个参数来定量评价断层的封闭程度。断层岩渗透率主要受断距、泥质含量、埋深等因素的控制;断层排替压力的预测方法有2种:一种是从断层岩成岩角度分析的"等效埋深法",另一种是分析实测排替压力与主控地质因素的"拟合法"。通过简化的断层模型,建立了渗透率、排替压力与主控因素的预测关系。和储层类似,流体在断层中的运移遵循多孔介质的渗流特征。利用断层两侧的流体压力和油气柱高度并不能直接评价封闭性能,还必须考虑油气充注史和流体压力变化历史。  相似文献   

3.
1800 m of drill core through the Nojima fault zone, Japan, reveals subsidiary fault and fracture networks that developed in the fault zone that triggered the 1995 Ms 7.2 Kobe earthquake. The subsidiary fault zones contain a fault gouge of < 1 cm bounded by thin zones of foliated cataclasite or breccia. Fractures are filled with calcite veins, calcite-cemented breccias, clay, and iron-oxide and carbonate alternation of the granitic host rock. These features are typical of extensional fractures that form the conduit network for fluid flux close to a major fault zone. The zone of distributed deformation surrounding the main fault is 50 m in width, and the dip of the Nojima fault at > 1 km depth is 75°. The fault-fracture networks associated with the Nojima fault zone are coseismic and were filled with carbonate and fine-grained material during repeated seismic-related infiltration of the fault zone by carbonate-bearing subsurface water. This study shows that fault-related fracture networks plays an important role as fluid flow conduits within seismically active faults, and can change in character from zones of high permeability to low permeability due to cementation and/or pore collapse.  相似文献   

4.
以野外观察描述为手段,系统研究了碳酸盐岩断裂变形机制的影响因素及断裂带结构演化过程,剖析了碳酸盐岩地层中断裂带结构与流体运移的关系。研究表明,影响碳酸盐岩内断裂变形机制的因素包括岩性、孔隙度、变形深度、温度、胶结作用、先存裂缝等,控制断裂带结构形成的因素包括滑动位移和破裂模式等。低孔隙度碳酸盐岩以裂缝发育为主,高孔隙度碳酸盐岩变形早期产生变形带,带内裂缝联接逐渐发育成断层带。随着埋藏深度的增加,断裂带结构不同:埋藏深度小于3 km,断层核主要发育无内聚力的断层角砾岩和断层泥;埋藏深度大于3 km,断层核普遍发育有内聚力的断层角砾岩和碎裂岩,破碎带发育多种成因的裂缝。随着位移的增加,破裂模式从早期的破裂作用变为后期的碎裂作用,最终形成碎裂流。断裂带演化是一个四维过程,断层核和破碎带发育情况直接影响断层对油气的运移和封闭的作用。断裂变形机制、断裂带内部结构以及与流体运移关系的研究,都可为封闭性提供重要的理论依据。  相似文献   

5.
张家口一蓬莱断裂带是一条北西西向活动断裂带。本文选取ETM+光学影像和SRTM高程影像作为主要数据源,结合研究区已有地质资料研究发现该带断裂构造的北西西向线性特征明显。从水系分布和错断地形等地貌标志判断,该断裂具有左阶组合样式和左行走滑活动特征。据遥感影像综合特征,可将该带分为张家口段、延庆-怀来段和北京一天津段,影像特征分段性显著,并与断裂带的分段性一致。研究结果表明,张家口-蓬莱断裂具有左行走滑的运动学特征,限制或错断北北东或北东向断裂,并且控制该区域的左阶雁列式第四纪盆地群和第四纪冲洪积物的分布。该断裂带各段对不同规模的水系分布和形态影响比较大,且北京-天津地区的华北平原段断裂对第四纪冲洪积扇和沿海地区的贝壳堤的形态和分布有一定的控制作用。地球物理深部数据和野外地质考察资料也证实了遥感解泽的结果,证明遥感技术在探查断裂构造空间展布和活动性鉴定中有着广泛的应用前景。  相似文献   

6.
张庆艳  陈卫忠  袁敬强  刘奇  荣驰 《岩土力学》2020,41(6):1911-1922
为了研究富水断层破碎带隧道突水突泥灾害演化机制,自行研制了一套可考虑质量迁移及地应力状态的大型室内突水突泥试验系统。利用该装置开展了不同水压加载方式、不同破碎带介质参数等条件的断层破碎带突水突泥灾害演化过程模拟试验。结果表明:(1)断层破碎带突水突泥灾害演化是渗流?侵蚀强耦合过程,在水压作用下,破碎带介质中的细颗粒首先发生迁移,导致充填介质孔隙结构增加,进而加速细颗粒流失,促使涌水率不断增长,随着细颗粒不断迁移流失,水流流态由层流转换为紊流,最终诱发突水突泥灾害;(2)破碎带介质初始孔隙率和施加水压越大越易诱发突水突泥,介质渗流演化特征越明显,渗流场参量如渗透率、孔隙率、雷诺数增加越快,且渗流场参量演化曲线出现突增现象;(3)梯度水压加载模式下断层破碎带介质较恒定水压加载条件下突水突泥演化特征更明显,介质发生突水突泥的临界水压更小。在此基础上,基于涌水率?时间(Q-t)、水力梯度?涌水率(i-Q)关系的流态转换分析和基于渗透率?水力梯度(k-i)关系的渗透性演化特征,建立了断层破碎带渗透演化特征概化模型。该研究结果对于断层破碎带突水突泥灾害演化机制与防治措施具有一定的理论指导价值。  相似文献   

7.
从断裂带内部结构出发评价断层垂向封闭性的方法   总被引:31,自引:1,他引:30  
脆性断层和塑性断层断裂带内部结构存在差异: 脆性断层断裂带由以断层岩和伴生裂缝为特征的破碎带和诱导裂缝带2部分组成; 塑性断层断裂带表现为几条充填断层泥大裂缝的组合, 诱导裂缝带不发育.破碎带内部伴生裂缝、无粘结力断层岩带和诱导裂缝带都可能成为油气运移的通道, 只有这3种通道均封闭, 脆性断层垂向才是封闭的.只要伴生裂缝封闭, 塑性断层就是封闭的.基于这种封闭机理, 分析了3种通道封闭的条件: 无粘结力断层岩带是否封闭取决于断层泥含量大小; 破碎带内部伴生裂缝的封闭性取决于断面压力和断层泥塑性强度关系; 诱导裂缝带封闭程度受控于后期成岩充填的程度.提出了利用断面压力、断层泥的含量和塑性强度、后期成岩程度综合判定不同性质断层垂向封闭性评价方法.并利用该方法对克拉2构造F1断层垂向封闭性进行了评价, 结果表明F1断层垂向封闭性具有分段性: ①和③段均表现为脆性, 但①段因诱导裂缝没有被充填不封闭, ③段是封闭的; ②段是塑性断层, 垂向封闭性好.这是克拉2构造有大规模天然气聚集成藏的关键因素之一.   相似文献   

8.
塔里木盆地台盆区深层海相油气勘探目标由层间岩溶向断控岩溶转变,并在处于坳陷区的富满地区发现了以走滑断裂为主控因素的断控型油田。富满地区储层特征与盆地内古隆起区、斜坡区均有不同,因此需要建立适合研究区的走滑断裂控储模式。本次研究通过高密度三维地震资料刻画了研究区走滑断裂的分布,利用岩心、测井、试井资料以及缝洞体识别技术明确了不同类型的储层分布,分析了研究区走滑断裂样式与差异变形对储层发育的影响,建立了走滑断裂控储模式。研究结果表明:(1)富满大型碳酸盐岩油气聚集区储集空间主要由多期走滑构造破裂作用与岩溶作用形成的洞穴型、裂缝-孔洞型、裂缝型与孔洞型空间组成;(2)走滑断裂活动性越强,断裂带宽度越大,储层发育规模越大,张扭段与压扭段断层破碎带型储层较平移段平面分布范围更广,纵向发育深度更大;(3)张扭段为汇水区,断裂联通性好,有利于大气流体下渗以及热流体上涌从而对储层进行溶蚀改造;压扭段为分流区,岩溶储层多发育于断裂带两侧,断裂开启程度低,受流体改造程度低于张扭段。  相似文献   

9.
On the basis of field observations, microscopic thin-sections and laboratory data analysis of ten faults in Xuanhan County area, northeastern Sichuan Basin, central China, the internal and megascopic structures and tectonite development characteristics are mainly controlled by the geomechanical quality in brittle formation of the Changxing-Feixianguan Formation. The fluid transportation performance difference between the faults formed by different geomechanics or different structural parts of the same fault are controlled by the mcgascopic structure and tectonite development characteristics. For instance, the extension fault structure consists of a tectonite breccia zone and an extension fracture zone. Good fluid transportation performance zones are the extension fracture zone adjacent to the tectonite breccia zone and the breccia zone formed at the early evolutionary stage. The typical compression fault structure consists of a boulder-clay zone or zones of grinding gravel rock, compression foliation, tectonite lens, and dense fracture development. The dense fracture development zone is the best fluid transporting area at a certain scale of the compression fault, and then the lens, grinding gravel rock zone and compression foliation zones are the worst areas for hydrocarbon migration. The typical tensor-shear fault with a certain scale can be divided into boulder-clay or grinding gravel rock zones of the fault, as well as a pinnate fractures zone and a derivative fractures zone. The grinding gravel rock zone is the worst one for fluid transportation. Because of the fracture mesh connectivity and better penetration ability, the pinnate fractures zone provides the dominant pathway for hydrocarbon vertical migration along the tensor-shear fault.  相似文献   

10.
The Southern Alps of New Zealand is an active oblique collisional mountain belt with extensive regional tectonically driven fluid flow. There is no evidence for igneous activity, and fluids consist of varying proportions of meteoric water and mid-crustal fluid derived from dehydration reactions. Fluid flow is controlled by fracture porosity, particularly in damage zones along faults and fault intersections. Gold and arsenic bearing veins exposed at the surface indicate two principal zones of gold mineralisation at depth. One of these is in the highest mountains, near to, but not in the region of maximum uplift. Deformation is dominated by reverse faulting, but some normal and strike-slip faults occur as well. The other zone of gold mineralisation is at and near the intersection of regional oblique dextral reverse faults and regional strike-slip faults. Both zones are characterised by small discontinuous vein systems, locally accompanied by ankeritic alteration of host rock. Veins occur in extensional and shear veins, and in dilational jogs with implosion breccias. Gold mineralisation occurred at many structural levels between the brittle–ductile transition and the near-surface region. The Southern Alps hydrothermal system represents an active roof zone to a mesothermal gold deposition system at depth. As such, this is a modern analogue for mesothermal gold terranes elsewhere in New Zealand and around the world. Observations on the regional distribution of fluid flow in active orogens can give insights into fluid flow at depth where gold mineralisation is occurring now. Comparison of these observations with ancient gold-bearing belts allows construction of three-dimensional concepts of orogenic fluid flow and gold mineralisation.  相似文献   

11.
The role of hydrothermal fluids in assisting the activity of strike-slip faults is investigated using a range of new geological, geophysical, and geochemical data obtained on the Argentat fault, Massif Central, France. This fault zone, 180-km-long and 6 to 8 km-width, has experienced coeval intense channeling of hydrothermal fluids and brittle deformation during a short time span (300–295 Ma). According to seismic data, the fault core is a 4-km-wide, vertical zone of high fracture density that rooted in the middle crust (~ 13 km) and that involved fluids in its deeper parts (9–13 km depth). If stress analyses in the fault core and strain analyses in the damage zone both support a left-lateral movement along the fault zone, it is inferred that hydrothermal fluids have strongly influenced fault development, and the resulting fault has influenced fluid flow. Fluid pressure made easier fracturing and faulting in zones of competent rocks units and along rheological boundaries. Repeated cycles of increase of fault-fracture permeability then overpressure of hydrothermal fluids at fault extremity favored strong and fast development of the crustal-scale strike-slip fault. The high permeability obtained along the fault zone permitted a decrease of coupling across the weak fault core. Connections between shallower and lower crustal fluids reservoirs precipitate the decrease of fault activity by quartz precipitation and sulfides deposition. The zones of intense hydrothermal alteration at shallows crustal levels and the zones of fluid overpressure at the base of the upper crust both controlled the final geometry of the crustal-scale fault zone.  相似文献   

12.
We describe an active right-lateral strike-slip fault zone along the southern margin of the Japan Sea, named the Southern Japan Sea Fault Zone (SJSFZ). Onshore segments of the fault zone are delineated on the basis of aerial photograph interpretations and field observations of tectonic geomorphic features, whereas the offshore parts are interpreted from single-/multichannel seismic data combined with borehole information. In an effort to evaluate late Quaternary activity along the fault zone, four active segments separated by uplifting structures are identified in this study. The east–northeast-trending SJSFZ constitutes paired arc-parallel strike-slip faults together with the Median Tectonic Line (MTL), both of which have been activated by oblique subduction of the Philippine Sea plate during the Quaternary. They act as the boundaries of three neotectonic stress domains around the eastern margin of the Eurasian plate: the near-trench Outer zone and NW–SE compressive Inner zone of southwest Japan arc, and the southern Japan Sea deformed under E–W compression from south to north.  相似文献   

13.
位于滇西北断陷带东北部、程海-宾川断裂带北端的永胜地区上新世以来断裂活动强烈,构造地貌特征显著。永胜地区1:50000活动构造填图发现,区内共存在各类断裂14条。其中金官断裂(F1)、永胜断裂(F2)、木耳坪羊坪断裂(F3)三者规模最大,活动性亦远超其他断裂,属于程海-宾川断裂带的一级分支断裂,其他断裂为程海-宾川断裂的二级分支断裂。构造地貌特征、错断地质体及擦痕统计等均指示区内断裂现今主要以伸展正断活动为主,根据活动性的差异可将其分为强、较强、中等、弱、极弱5类,其中金官断裂的活动性最强,垂向活动速率可达0.20~0.26 mm/a。对永胜地区主要断裂几何学、运动学特征的研究及动力学机制的讨论可知,永胜地区主要断裂在平面上构成向东突出的弧形旋扭构造体系,在剖面上表现为张扭性断裂常见的负花状构造;程海-宾川断裂带现今活动主要是在近南北向主压应力作用下产生的近东西向的伸展正断,并因为叠加了旋扭作用而具有一定左旋走滑。永胜地区的弧形旋扭构造体系及滇西北断陷带等均是在川滇内弧带顺时针旋转及南汀河断裂、畹町断裂与理塘断裂的走滑拉分共同作用下形成的。   相似文献   

14.
南白碱滩断裂带结构特征及流体作用   总被引:1,自引:0,他引:1  
南白碱滩断裂带可分为滑动破碎带和诱导裂缝带两个结构单元。滑动破碎带具断裂角砾岩特征,厚度小,压实强,岩性致密,封闭性好;诱导裂缝带宽度大,裂缝发育,胶结充填作用强。断裂充填物主要为方解石,其次为方沸石,另外还发现硅质和沥青充填。充填物中流体包裹体发育,有盐水包裹体,也有有机包裹体,主要沿方解石解理面和微裂隙呈线状分布。盐水包裹体均一温度可分为3个区间,有机包裹体在荧光镜下也显示出棕色、亮黄色及蓝绿色3种颜色,表明南白碱滩断裂带至少经历了3期大规模的流体活动。成岩胶结作用对南白碱滩断裂带的封闭性起重要作用,受后期构造运动的影响,早期封闭性断裂会重新开启,流体将再次活动,形成新的胶结物,故该断裂的封闭是多期流体活动发生成岩胶结作用的结果。   相似文献   

15.
裂谷盆地的断层封闭类型   总被引:6,自引:0,他引:6       下载免费PDF全文
张树林 《地球科学》1995,20(3):250-255
对油气运移和聚集而言,裂谷盆地的断层可分为断面封闭型和生封闭型两大类;断面封闭型以以断面(或断裂带)本身作为遮挡体或通道;岩性封闭型断层依靠对盘财层遮挡或提供通道,根据断层的封闭能力,每大类还可分为完全封闭型、不完全封闭型和开启型3亚类、磊断层以断面封闭型为主;小断层大断层在浅层的分支断层都为生封闭型,但者的油气分布特所不同,一盘为基岩的断层较在盖层内的断层能力低,断层活动有利于油气运移。  相似文献   

16.
The Bolivian Sub-Andean Zone (SAZ) corresponds to a Neogene thrust system that affects an about 10-km thick Palaeozoic to Neogene siliciclastic succession. The analysis of macro and microstructures and cement distribution in thrust fault zones shows that they are sealed by quartz at depths >3 km, due to local silica transfer by pressure-solution/precipitation activated at temperatures >70–90 °C. At shallower depths, faults have remained open and could be preferential drains for lateral flow of carbonate-bearing fluids, as shown by the occurrence of carbonate cements in fractures and their host-sandstone. Due to decreasing burial, resulting from foothill erosion during fault activity, critically buried fault segments can be affected by non-quartz-sealed structures that post-date initial quartz-sealed structures. The integration of textural, fluid inclusion and isotopic data shows that carbonates precipitated at shallow depth (<3 km), low temperature (<80 °C) and relatively late during the thrusting history. Isotopic data also show that precipitation occurred from the mixing of gravity-driven meteoric water with deeper formation water bearing carbonate carbon derived from the maturation of hydrocarbon source rocks (Silurian and Devonian shales). The combined microstructural and isotopic analyses indicate that: (i) fluid flow in fault zones often occurred with successive pulses derived from different or evolving sources and probably related to episodic fault activity, and (ii) at a large-scale, the faults have a low transverse permeability and they separate thrust sheets with different fluid histories.  相似文献   

17.
The Pacific–Australian tectonic plate boundary through the South Island of New Zealand consists of the transpressional Southern Alps mountain belt and the transcurrent Marlborough Fault System, both of which have active tectonically driven hydrothermal systems, with topographically driven meteoric incursion and warm springs. The Southern Alps hydrothermal system is relatively diffuse, with little or no fault control, and is channelled through scattered extensional sites beneath the mountains, where gold mineralisation is occurring locally. The hydrothermal activity along the Marlborough Fault System is controlled by the principal faults in well-defined valleys separated by narrow high ridges. Lateral evolution of Marlborough fault strands southwestwards into the Southern Alps has caused diversion of diffuse Southern Alps hydrothermal activity into the structural superimposition zone, where fluid flow is increasingly being controlled by faults. This hydrothermal diversion was accompanied by major topographic reorientation and river drainage reversal in the late Quaternary. Vein swarms now exposed in the remnants of the Southern Alps north of the superimposition zone formed at shallow levels, with some evidence for fluid boiling, from a mixture of meteoric and deep-sourced fluid. These veins, some of which contain gold, are part of an abandoned <1 million-year-old hydrothermal zone beneath the fossil topographic divide of the Southern Alps that has now been dismembered by lateral incursion of the Marlborough fault strands. Observations on this active plate boundary provide some insights into processes that controlled orogenic gold mineralisation in ancient belts, particularly with respect to relationships between hydrothermal fluid flow, structure and topography.  相似文献   

18.
The impact of inclined faults on the hydrothermal field is assessed by adding simplified structural settings to synthetic models. This study is innovative in carrying out numerical simulations because it integrates the real 3-D nature of flow influenced by a fault in a porous medium, thereby providing a useful tool for complex geothermal modelling. The 3-D simulations for the coupled fluid flow and heat transport processes are based on the finite element method. In the model, one geological layer is dissected by a dipping fault. Sensitivity analyses are conducted to quantify the effects of the fault’s transmissivity on the fluid flow and thermal field. Different fault models are compared with a model where no fault is present to evaluate the effect of varying fault transmissivity. The results show that faults have a significant impact on the hydrothermal field. Varying either the fault zone width or the fault permeability will result in relevant differences in the pressure, velocity and temperature field. A linear relationship between fault zone width and fluid velocity is found, indicating that velocities increase with decreasing widths. The faults act as preferential pathways for advective heat transport in case of highly transmissive faults, whereas almost no fluid may be transported through poorly transmissive faults.  相似文献   

19.
塔里木盆地走滑带碳酸盐岩断裂相特征及其与油气关系   总被引:2,自引:0,他引:2  
通过露头与井下资料的综合分析,塔里木盆地奥陶系碳酸盐岩走滑断裂带断裂相具有多样性,根据内部构造发育程度可以分为断层核发育、断层核欠发育两类。露头走滑带断层核部以裂缝带、透镜体、滑动面等断裂相发育为特征,断裂边缘的破碎带发育裂缝带、变形带。裂缝带主要分布在断层核附近50m的破碎带内,裂缝多开启,渗流性好。断裂核部透镜体发育,在破碎带也有分布,破碎角砾组合的透镜体多致密。滑动面具有平直截切型、渐变条带型等两种类型,多为开启的半充填活动面。变形带多为方解石与碎裂岩充填,破碎带局部部位裂缝与溶蚀作用较发育。利用地震剖面、构造图、相干图等资料可以判识塔里木盆地内部奥陶系碳酸盐岩走滑断裂相的特征及其发育程度,沿走滑断裂带走向上断裂相具有分段性与差异性,根据渗流性可以定性区分高渗透相、致密相区。沿断裂带高渗透相区是碳酸盐岩缝洞体储层发育的有利部位。断裂相的横向变化造成油气分布的区段性,形成高渗透相输导模式、致密相遮挡模式等两类成藏模式。走滑断裂带碳酸盐岩断裂相的特征及其控藏作用对油气勘探开发储层建模具有重要意义。  相似文献   

20.
对鄂尔多斯盆地基底断裂特征及其活动性作了总结、归纳与分析。结果表明,鄂尔多斯盆地不仅是一个四周被活动断裂或深大断裂围限的块体,其内部还存在大量规模不等的基底断裂,并具有明显的分区特征。盆地内基底断裂带可分成4组:几乎贯穿整个盆地的华池-米脂-大同北东向断裂带;盆地北部的多条东西向断裂带和中部的定边-绥德、南部的庆阳-富县-宜川等东西向断裂带;中部发育的定边-吴起、乌审旗-榆林北西向断裂带与盆地东西两侧的近南北向巨型断裂带。鄂尔多斯盆地内存在的现代构造地貌以及普遍发育的雁行状、X共轭状节理等现象,是新构造运动的直接表现;盆地内存在的深部流体活动信息、现代地球化学景观特征以及众多的小地震、微地震活动及其与基底构造的密切关系,反映了这些断裂的现代活动性。  相似文献   

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