断层封堵分析方法

断层封堵分析方法断层封堵分析是当今应用地球物理方法研究油气储存、运移的一种有效方法，这是因为在勘探区或油田内，由于大多数圈闭是以断层做为边界的，断层可以部分或全部地控制油田或勘探区的油气，因此对断层封堵的预测以及各种控制因素的分析，可以解释油气运移路...     

临南洼陷临邑断层封闭性的模糊综合评价

临南洼陷是惠民凹陷的生烃中心,临邑断层作为临南洼陷的主控断层对油气的运移和聚集起着重要的作用,弄清临邑断层的封闭性具有重要意义.影响断层封闭性的主要因素有断层的力学性质、几何性质、断面所受正应力、断层两侧的界岩关系以及泥岩涂抹系数5个方面.运用模糊数学的方法对影响断层封闭性的5个因素进行了定量评价,结果表明,影响本区断...     

东海陆架盆地南部生长断层活动特征

生长断层是在伸展和走滑盆地中一种重要且广泛存在的构造样式。通过地震资料定性识别出东海陆架盆地南部地区18条生长断层;根据断裂对研究区各级构造单元控制作用和纵向切穿地层情况,将其划分为一级控盆断裂、二级控凹断裂、三级控带断裂和盖层断裂;通过断裂平面分布特征研究认为研究区的断裂以NE、NNE延伸为主,少数为NEE方向;利用地震剖面在研究区识别出阶梯状组合断层带、“Y”字型组合断层、多米诺式断层带、地堑、地垒等多种断裂组合样式;又结合生长指数和断层落差两种方法对研究区生长断层的运动学特征进行了定量统计分析,发现研究区生长断层在古近纪时期活动强度具有自西向东逐渐递减趋势,区内断层活动期次自西向东逐渐变新,整个研究区内生长断层在古近纪盆地裂陷—断陷期活动强度最大,中新世后断裂活动趋于稳定。认为晚中生代以来太平洋板块西缘俯冲后撤和印度板块向亚欧板块俯冲碰撞在东海陆架盆地形成的远程蠕散效应,使东海陆架盆地形成了拉张伸展应力场环境,是研究区发育大量生长断层的首要原因。同时,加强对研究区生长断层伴生构造如滚动背斜和缓坡带阶梯状断裂组合封堵形成的岩性圈闭研究,有利于推动东海陆架中新生代盆地资源勘探可持续发展。     

渤海渤中A区断层差异输导及控藏作用分析

渤中A区位于渤海海域的渤南低凸起北部斜坡带,前期勘探重点为潜山与古近系,而新近系的含油气性日益引起重视.从油气输导体系研究入手,明确了断层垂向输导油气是新近系成藏的关键,通过断层样式、断层活动性的分析,认为背形负花状构造及断层活动差异共同控制新近系差异成藏,并指示构造脊部位是油气优势的运移方向.另外,利用分形几何学原理,对研究区断层分形特征进行研究,构造脊部位断层分形分维数值较高,表明构造脊部位油气运移效率较高,佐证了常规方法的论断且对断层输导体系进行半定量-定量的评价.近期钻井在构造脊部位的新近系有良好发现,证实了断层输导分析的正确性.     

用评价因子法研究北部湾盆地涠西南凹陷断层封闭性

选取了断层的产状、断层力学性质、断层断面曲率、断面压力、最大主应力与断层走向夹角、断层两盘岩性配置关系和断层沿走向形态等8个评价因子,构建了断层封闭性评价模型。在不同的平面位置、不同的剖面深度半定量评价了研究区与4个主要局部构造相关的9条目标断层现今时期封闭能力。评价结果显示,从断层封闭性角度来优选,W10-1构造和W10-3构造最佳,W9构造中等,W10-2构造次之。     

相干体解释断层方法测试及泾河油田的应用

三维地震相干体技术是近年来发展起来的一项新技术,在三维地震解释、特别是断裂解释中应用效果明显。在一些地区和特殊岩性体、特殊类型油藏研究方面取得了良好效果,并且可以较为深入准确地刻画小断层。主要针对鄂尔多斯盆地泾河油田的相干数据体计算做了参数和方法优选,通过对相干层位切片的分析研究,得出了适用于研究区的油藏特征的计算方法和计算参数,达到了准确刻画断层间接预测裂缝发育带的目的。     

琼东南盆地陆架区晚中新世以来断层活动性研究

对琼东南盆地陆架区晚中新世以来的断层活动性进行研究, 有助于理解南海西北部晚中新世以来的构造演化, 也对该区钻井平台的安全性评估、海洋工程勘查以及区域稳定性评价等有重要意义。研究区断层走向主要为NWW向, 多数断层在晚中新世时期停止活动。通过对断层几何形态的统计分析以及使用高分辨率断层落差图法(T-Z图示法)对断层活动性进行量化分析, 结果显示: 断层活动性在晚中新世末期(5.5Ma)发生转变; 研究区南部的断层落差值大于北部; 南部断层停止活动的时间较北部断层稍晚。这些研究成果表明, 晚中新世末期研究区断层受构造应力变化的影响, 在生长发育过程中断层活动性质发生了改变, 由逆断层转为正断层。红河断裂带对琼东南盆地的构造演化起着重要的控制作用, 文章推测研究区断层活动性变化是由红河断裂带的构造反转所导致, 因为红河断裂带在5.5Ma时发生了走滑运动的反转, 与研究区的断层活动性变化在时间和性质上相耦合。     

济阳坳陷商河油田断层与油气运聚的关系

利用断层落差法、生长指数法和泥岩涂抹SGR法分析了商河油田断层活动性和封闭性特征,并结合油气分布分析了断层与油气运聚之间的关系。研究结果表明,商河油田1号、2号、3号及6号断层在馆陶期持续活动,是油气向中浅部沙一段等储集层运移的有利垂向通道;同时,具有良好侧向封堵条件的断层容易使油气聚集成藏,认为SGR=0.75是断层侧向封闭的临界条件。     

济阳坳陷商河油田断层与油气运聚的关系

利用断层落差法、生长指数法和泥岩涂抹SGR法分析了商河油田断层活动性和封闭性特征,并结合油气分布分析了断层与油气运聚之间的关系。研究结果表明,商河油田1号、2号、3号及6号断层在馆陶期持续活动,是油气向中浅部沙一段等储集层运移的有利垂向通道;同时,具有良好侧向封堵条件的断层容易使油气聚集成藏,认为SGR=0.75是断层侧向封闭的临界条件。     

东海西湖凹陷平湖斜坡带断层特征及其封闭性

在对西湖凹陷平湖斜坡带断裂系统特征定性分析的基础上,结合断层封闭性的半定量研究,总结了平湖斜坡带断层的封闭性特征。依据主干断裂及伴生断裂的平面组合样式、剖面组合关系等特征,将平湖斜坡带断裂系统划分为4个断裂带,由北至南依次为"K"同向断裂带、"W"反向断裂带、"P"同向断裂带和"N"堑式断裂带。断层封闭性研究认为平湖斜坡带中部断层封闭性要好于南部和北部。"K"同向断裂带和"W"反向断裂带多数断层封闭性较好,但由于平湖主断裂的长时间活动,使得整体封闭性一般。"P"同向断裂带由于受中新世末龙井运动的弱挤压反转作用,断层的封闭性较好。"N"堑式断裂带由于平湖主断裂的长期活动和沉降期断裂的存在,断层封闭性较差。     

Transtension of the Romanche transform fault

Areas of transtension are discovered in the western part of the Romanche transform fault. Geodynamical parameters of the transtension are calculated on the basis of three-dimensional modeling of the inversive magnetic layer using survey data. The interval spreading rates calculated on this basis appeared to be smaller (1.65 cm/y for paleoanomalies C1-C5E on the northern side of the fault and 1.56 cm/y for paleoanomalies C6–C24 on the southern side) than those derived from the theoretical concepts based on the NUVEL-1 and NUVEL-1A models.     

Scaling of fault attributes: A review

The present paper reviews our current understanding of fault dimensions and their scaling laws, with special focus on faults in siliciclastic rocks. The aim is to provide a comprehensive overview of recent research in order to identify strengths and challenges related to the way this topic is being addressed. We here investigate the statistical distributions of different fault attributes, e.g. fault length, displacement, damage zone width, core thickness at different scales and tectonic regimes. Biases related to sampling (resolution effect) and statistical visualization of data are discussed. The interrelationship between different faults attributes is addressed, e.g. fault displacement versus length, and fault core thickness and fault damage zone width. The results of this study show that global statistical relationships for fault attribute populations may not be valid, since the fault attributes at different scales behave differently and the compiled data on fault displacement-length exhibit breaks in the transition between faults at different scales, i.e. from small to medium scale faults at ∼1 m displacement and from medium to large scale faults at ∼1000 m displacement. This may also be the case for fault displacement-core thickness and fault displacement-damage zone width, as slight variation in the relationship can be observed between attribute populations derived from small- and medium-size faults at ∼1 m displacement. These differences may indicate the existence of characteristic length scales in fault populations, which could imply a hierarchical ordering of fault systems. The majority of data in our compiled database show no clear distinction between rocks from different lithologies and tectonic settings. Finally, the mechanical aspects of the processes of faulting with respect to the scaling relationships are discussed. Conceptual diagrams for the evolutionary processes of faulting at different scales based on the observed relationships on the plotted datasets of faults’ main attributes (fault displacement, length, core thickness and damage zone width) are proposed.     

海底光缆故障判定及测试方法

在海底光缆不可避免的发生故障后，准确、迅速地判断海底光缆故障情况，以及根据所获得的测试数据来确定故障点的位置，成为海底光缆修复流程中极其关键的步骤。介绍了海底光缆故障的几种类型，并针对不同的故障类型，根据其特性给出了相应的测试方法来判定故障点，从而为海底光缆发生故障后，迅速修复奠定了技术基础。     

Deep tow studies of the Tamayo transform fault

The Tamayo transform fault occurs at the north end of the East Pacific Rise where it enters the Gulf of California. The two deep-tow surveys reported here show that the transform fault zone changes significantly as a function of distance from the spreading center intersections. At site 1, near the intersection, one side of the fault is young and the fault zone is narrow and well-defined. Strike slip occurs in a zone approximately 1-km wide suggesting a correspondingly narrow zone of decoupling between the Pacific and North American plates. On the young side of the strike-slip zone, normal faults occur along shear zones which are 45°–50° oblique to the transform strike. They occur parallel to the short axis of the strain ellipse for transform fault strain here, i.e., perpendicular to the least compressive stress. The transform walls are formed by normal faulting as has been pointed out in previous detailed surveys. Here, however, the age contrast of 2.5 m.y. across the transform valley is apparent in the morphology of the normal fault scarps. While the scarps are steep and well-defined on the young side, the scarps on the older side have gradual 10°–30° slopes and appear to be primarily talus ramps. Apparently, the scarps have been tectonically eroded by continued strike slip activity after the initial stages of normal faulting. Thus, transform valleys should be quite asymmetric in cross-section where there is a significant age contrast and one side is less than approximately 0.5 m.y. old. Also, along older sections of the transform valley walls, normal faulting may not be at all obvious due to degradation of the scarps by tectonic erosion. This phenomenon makes the likelihood of transform faults providing windows into the oceanic crust most unlikely except in special cases.The picture of transform deformation is more complex at site 2 in the central portion of the fault where both sides of the fault are greater than 1 m.y. old. Here the transform valley is wider (25–30 km as opposed to 2–5 km). There is no clear simple zone of strike slip tectonics. In fact, the only clear evidence for deformation is the intrusion of magmatic or serpentinite diapirs through the sediments of the transform valley floor. The diapirs have deformed the turbidite layers flooring the valley and in one carefully studied case the turbidite sequence has been uplifted, perched atop the diapir. The pattern of deformation on this outcropping diapir shows radial and concentric fractures which can be modeled by a vertical intrusion circular in plan view. Magnetic studies limit the possible composition to basalt or serpentinite. A 60-km-long median ridge is also likely to be the product of intrusion along the transform fault. The survey at site 2 pointed out the importance of vertical tectonics in the transform valley floor and in particular the importance of diapiric intrusions of either basaltic or serpentinite composition.Based on initial boundary conditions and present tectonic elements in the Tamayo fault zone, a possible history of the mouth of the Gulf of California is outlined. The median ridge was emplaced starting approximately 0.8 m.y. ago by regional extension across the transform fault, the result of leaky transform faulting. The diapirs occur along a possible relay zone of extension midway along the fault which began approximately 0.15 m.y. ago. The extension in this case is parallel to the trend of the transform fault, is still occurring at present, and may evolve into a true spreading center.Contribution of the Scripps Institution of Oceanography, new series.     

高邮凹陷南断阶许庄—竹墩地区断层发育演化和油气成藏

为了揭示高邮凹陷南断阶许庄—竹墩地区复杂断裂系统的成因、演化与油气成藏的关系,通过对不整合面地层剥蚀量计算、构造演化剖面分析等方法,系统地总结了许庄—竹墩地区断层的发育演化规律。吴堡运动和三垛运动时期是断裂活动最强烈的时期,许庄—竹墩地区的地层受到较强的剥蚀作用。本区主要断层的发育顺序依次为真①断层、纪③断层、真②’断层和真③断层,同一断层在不同的地质时期和平面上的不同位置,发育强度有明显的差异性。断层的活动一方面形成了一系列的断块圈闭,另一方面是油气垂向运移的主要通道,因此在本区形成了一系列的断块圈闭油藏。     

基于模糊故障树方法的脐带缆可靠性分析研究

脐带缆作为水下生产系统的“神经生命线”,是水下生产系统的关键一环,其可靠性问题越来越受到关注。影响脐带缆可靠性的事件具有随机性,目前缺乏对这些随机事件发生概率的统计,难以直接对其可靠性进行定量分析。基于模糊数理论和故障树结合的方法对脐带缆可靠性进行分析,首先获得引起脐带缆失效的40个最小割集及底事件重要度排序。其次采用基于模糊集理论的定量分析对脐带缆故障树系统中的底事件进行统计计算,得到各底事件的失效概率,最终计算出顶事件概率,并得出导致脐带缆失效的主要因素依次为护套/铠装失效、钢管失效、电缆失效,为脐带缆的安全运行提出适当的建议。     

A seismic design method for subsea pipelines against earthquake fault movement

As there are no specific guidelines on design of subsea pipelines crossing active seismic faults, methods for land buried pipelines have been applied to. Taking the large seismic fault movement into account, this paper proposes improved methods for seismic designs of subsea pipelines by comprehensively investigating the real constraining of soil on the pipelines, the interaction processes of soil with the pipeline, the plastic slippage of the soil, and the elastic-plastic properties of the pipeline materials. New formulas are given to calculate the length of transition section and its total elongation. These formulas are more reasonable in mechanism, and more practical for seismic design of subsea pipelines crossing active faults.     

The development of polygonal fault systems by syneresis of colloidal sediments

Polygonal fault systems occur in numerous sedimentary basins worldwide, are generally located on passive margins in onlap fill units and tend to comprise the finest grained sediments in this geological setting. These fault systems have been most thoroughly described in the central North Sea basin and the detailed structure shows a significant correlation with lithological variations, both vertically and laterally. Extension measured in stacked decoupled tiers of polygonal faults correlates positively with both clay fraction and smectite content. Lateral facies variations are also observed and indicate that time-equivalent sequences upslope from the smectite-rich polygonally faulted sediments are coarse-grained, clay-poor and undeformed. This leads us to believe that the structure and geometry of the fault system are controlled by the colloidal nature of the sediments, and that the volumetric contraction measured on seismic sections can be accounted for by syneresis of colloidal smectitic gels during early compaction. Syneresis results from the spontaneous contraction of a sedimentary gel without evaporation of the constituent pore fluid. This process occurs due to the domination of interparticle attractive forces in marine clays, dependent on environment, and is governed by the change of gel permeability and viscosity with progressive compaction. The process of syneresis can account for a number of structural features observed within the fault systems, such as tiers of faults, the location of maximum fault throw and growth components at upper fault tips. As such, this paper represents the first attempt to correlate microscale properties of clay-rich sediments to their macroscale seismic character.     

南沙海槽断裂带活动性初步分析

主要讨论了南沙海槽断裂带的活动性和构造演化过程,并对海槽及附近海域的地质稳定性因素进行了分析。发现南沙海槽有活动断裂、火山岩侵入、海底滑塌和地震等不稳定因素。南沙海槽形成演化过程较为复杂,经历过多期逆冲推覆变形和褶皱隆升等构造活动,其中逆冲和隆升等活动现今可能仍在进行,属于次不稳定区域。另外,海槽西南端有滑塌现象和海底阶梯存在,工程地质条件较差。所以,海槽及邻近海区的工程建设需要特别注意这些不稳定因素,应尽量避开不稳定地区或采取工程加固措施等。     

An application of fuzzy fault tree analysis for spread mooring systems

In this paper, a fuzzy fault tree analysis methodology for spread mooring systems is presented. The methodology combines the effects of operational failures and human errors under fuzzy environment for the spread mooring configurations. In conventional fault tree analysis (FTA), which is an established technique in hazard identification, the ambiguous and imprecise events such as human errors cannot be handled efficiently. In addition to this, the tolerances of the probability values of hazards are not taken into account. Moreover, it is difficult to have an exact estimation of the failure rates of the system components or the probability of the occurrence of undesired events due to the lack of sufficient data. To overcome these disadvantages, a fault tree analysis based on the fuzzy set theory is proposed and applied to the spread mooring system alternatives. Furthermore, sensitivity analysis is carried out based on the fuzzy weighted index (FWI) in order to measure the impact of each basic event on the top event. The results show that the fuzzy fault tree risk analysis method (FFTA) is more flexible and adaptive than conventional fault tree analysis for fault diagnosis and hazard estimation of spread mooring systems.