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1.
莺歌海盆地发育多期泥.流体底辟.底辟活动的多期性造成底辟区断裂和裂隙不断开启,输导天然气从深部向浅部垂向运移,充注底辟两侧及周缘的砂体,在剖面上构成树形样式,称之为底辟树型输导系统.底辟树型输导系统连通了浅层和中一深层的构造和岩性圈闭,是莺歌海盆地中央凹陷带构造及岩性天然气藏成藏的主要输导通道和样式,其相应运移方式分为能量保持型和能量释放型两种.本文提出了莺歌海盆地中央凹陷带发育底辟树型输导系统及其运移的地质模型,泥-流体底辟活动控制下的底辟树型输导系统及其运移模型是对伸展-转换盆地油气成藏理论的发展和补充. 相似文献
2.
珠江口盆地白云凹陷中央底辟带的发现及识别 总被引：22，自引：0，他引：22
白云凹陷属珠江口盆地的一个次级构造单元.通过对二维地震剖面上模糊带的分析, 凹陷中心发育北西西向展布、面积约1000km2的底辟带, 底辟幅度最大可达8km.高精度磁力资料显示底辟带为一个低磁异常区.底辟构造包括龟背上拱、弱刺穿、气烟囱、底辟断层(或裂缝)、海底麻坑等类型, 主要发源于断陷期深湖相的文昌组(始新统) —恩平组(上始新统-下渐新统), 其次为坳陷期浅海-深海相沉积的珠江组(下中新统) —韩江组(中中新统) 的两套巨厚富泥沉积层.白云凹陷具有快速沉降、细粒充填为主、以及新生代的右旋张扭性应力场, 共同造就了凹陷中央底辟带的发育.底辟构造的存在反映了白云凹陷中心曾经蕴育着高温、超压系统, 与之密切伴生的大量亮点指示着沿底辟构造的天然气垂向输导, 构成了古近系油气运移到新近系—第四系的成藏动力系统. 相似文献
3.
莺歌海盆地天然气底辟优势聚集规律及勘探意义 总被引：1，自引：0，他引：1
莺歌海盆地的高温高压环境、构造断裂不发育、泥-流体底辟发育及热流体活动强烈等独特的地质条件,决定了伸展-转换盆地的油气聚集规律与断陷盆地复式油气聚集具有明显的差异性。在分析天然气成藏主控因素的基础上,以天然气藏形成到天然气分布为主线,提出莺歌海盆地的天然气底辟优势聚集规律:即宏观上天然气聚集在盆地内成藏条件配置好的中央凹陷带底辟区,微观上天然气则聚集在底辟成藏条件配置好的顶部、两侧及周缘的构造和岩性圈闭中。天然气底辟优势聚集规律突破了以往紧邻凹陷带的斜坡带是油气聚集最有利区带的传统观点,使人们认识到只有符合优势聚集规律的构造带和圈闭才可能聚集天然气,这对于调整伸展-转换型盆地的油气勘探思路,针对性地解决莺歌海盆地勘探中存在的问题,进一步指明有利勘探方向具有重要的指导作用。 相似文献
4.
DF1-1底辟区构造应力场及渗流场演化的数值模拟研究 总被引：3，自引：1，他引：2
DF1-1底辟区是莺歌海盆地内超压流体最活跃的地带之一.超压流体的活动直接受控于构造应力及其形成的不同类型的断裂和裂隙构成的输导系统.从底辟区大规模流体垂向活动以及幕式活动的特征来看, 流体流动的动力主要是由于垂向压差的存在以及渗流场变化引起的局部应力场(包括热应力场) 的作用所致.在详细研究底辟区的构造及流体活动关系的基础上, 对底辟区构造应力场及渗流场的演化进行了模拟.结果显示: 构造运动引起的应力场决定了DF1-1底辟区油气沿主要断裂系走向迁移的总趋势, 在底辟区流体从底辟的两侧向其中心运移, 由底辟体中向上运移为主; 高压流体产生的热应力控制局部应力场状况及油气运移方向, 驱动流体向底辟体顶部运移, 当热应力值过大时有可能改变应力场状况以及油气运移总趋势. 相似文献
5.
南海北部深水区荔湾凹陷构造演化及其石油地质意义 总被引：1，自引：0，他引：1
荔湾凹陷北与白云凹陷相邻,南与双峰盆地(南海西北次海盆)相接,发育于洋陆过渡边界,具有独特的结构构造特征。选取荔湾凹陷为研究对象,在3D地震资料解释的基础上,以断裂特征分析厘定凹陷性质、构造古地貌恢复解析凹陷结构,进而指出古地貌恢复和构造演化对油气勘探的影响。研究获得三方面的创新性认识:①荔湾凹陷为洋陆过渡壳上发育的断坳,断坳作用占主导地位;②32Ma的底辟作用将荔湾凹陷改造为"四洼三凸"的构造格局,恩平组沉积期凹陷北部是一个连通的洼陷;③恩平组沉积期连通洼陷的古地貌有利于三角洲(烃源岩)的发育,背斜型圈闭的定型受控于32Ma的底辟作用,是荔湾凹陷油气勘探的有利目标。 相似文献
6.
荔湾凹陷北与白云凹陷相邻,南与双峰盆地（南海西北次海盆）相接,发育于洋陆过渡边界,具有独特的结构构造特征。选取荔湾凹陷为研究对象,在3D地震资料解释的基础上,以断裂特征分析厘定凹陷性质、构造古地貌恢复解析凹陷结构,进而指出古地貌恢复和构造演化对油气勘探的影响。研究获得三方面的创新性认识：①荔湾凹陷为洋陆过渡壳上发育的断坳,断坳作用占主导地位;②32Ma的底辟作用将荔湾凹陷改造为“四洼三凸”的构造格局,恩平组沉积期凹陷北部是一个连通的洼陷;③恩平组沉积期连通洼陷的古地貌有利于三角洲（烃源岩）的发育,背斜型圈闭的定型受控于32Ma的底辟作用,是荔湾凹陷油气勘探的有利目标。 相似文献
7.
琼东南盆地深水区发育泥-流体底辟构造,为油气垂向运移提供通道。文章基于琼东南区域构造与沉积演化认识,利用高精度三维地震资料,对深水区底辟构造进行了系统研究,识别出了底辟的分布范围,并分析了其发育机制以及对天然气成藏的控制作用。琼东南盆地深水区底辟主要发育在乐东—陵水凹陷结合部的陵南斜坡带及凸起之上,向凹陷中心规模逐渐减小。新近纪时期盆地快速沉降和生烃作用共同导致了深部异常高压的存在,其为底辟发育提供了原始的驱动力;陵南斜坡带古近纪发育的断裂为区域内的构造薄弱带,且在新近系发生活化为异常高压释放提供突破口,进而导致了底辟的形成,即底辟形成时间为新构造运动时期。底辟构造可沟通崖城组烃源岩及黄流组、莺歌海组储集体,是深水西区油气垂向运移的主要通道,控制了天然气藏的分布。根据底辟构造与烃源、储层的配置关系,提出了陵南斜坡带和松南低凸起区是深水区下步勘探的重点区带。 相似文献
8.
Zhang Jiahua 《地球科学》1986,(3)
底辟构造在我国东部沉积盆地中有广泛的分布,并蕴藏有丰富的油气资源。作者模拟了隐刺穿构造的发育过程及其变形特征,从而分析底辟发育的力学机制。实验结果表明,底辟的形成时间和底辟核的形态对底辟变形有重大影响。绝大多数隐刺穿构造。在其顶部都发育一个地堑断裂系,这是底辟构造的共同特征。 相似文献
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10.
《矿物岩石》2017,(3)
南海北部各盆地普遍存在含CO_2气藏。莺歌海盆地CO_2主要受泥底辟带热流体上侵作用的控制,异常高CO_2仅在泥底辟带发现。然而珠江口盆地白云凹陷的泥底辟带与CO_2的关系暂不明确。通过收集分析珠江口盆地的60组(含/高含)CO_2气藏的气体组分和气体同位素地球化学数据,其R/Ra比值(样品的3 He/4 He与空气的3 He/4 He比值)均2,CO_2成因主要为火山幔源型,不同于以壳源型为主的莺歌海盆地。位于白云凹陷中央泥底辟带的B1井,其CO_2碳同位素δ13 C值约-10.9‰~-10.5‰,根据自生片钠铝石的出现认为曾有CO_2大量聚集,而且CO_2分压高,推测为有机、无机成因混合气,不同于非泥底辟带的幔源无机成因。通过不同构造位置上的3口典型单井的对比分析及其与莺歌海盆地,以及泥底辟带和非泥底辟带的对比研究,认为凹陷周缘凸起上的断裂带和凹陷内的泥底辟带是高含CO_2气藏的主要分布区,认为白云凹陷泥底辟构造对于CO_2分布具有一定的控制作用。 相似文献
11.
摘要：详细阐述不同成因的泥底辟流体输导模式,探讨了泥底辟输导体系的演化与天然气水合物成藏之间的关系,并分析神狐海域泥底辟输导体系对天然气水合物成藏的影响。底辟核外部伴生断裂、底辟核内部流体压裂裂缝和边缘裂缝带均可作为输导流体的通道。根据运移通道和动力等差异性,提出泥底辟输导流体的2种端元模式：超压-流体压裂输导型和边缘构造裂缝输导型。在此基础上,讨论了泥底辟(泥火山)的不同演化阶段对水合物的形成、富集和分解的影响。早期阶段,泥底辟形成的运移通道可能未延伸到水合物稳定带,导致气源供给不够充分;中期阶段,水合物成藏条件匹配良好,利于天然气水合物生成;晚期阶段,泥火山喷发引起水合物稳定带的热异常,可能导致水合物分解,直至泥火山活动平静期,水合物再次成藏。神狐海域内泥底辟分为花冠状和穹顶状两类,花冠状泥底辟以超压-流体压裂输导型为主;穹顶状泥底辟以底辟边缘裂缝输导型为主。泥底辟输导体系的差异性可能是神狐海域天然气水合物非均质分布的影响因素之一。
关键词：泥底辟;输导体系;天然气水合物;成藏机制;神狐海域 相似文献
12.
Sbastien Blanchard Edward J. Matheson Christopher R. Fielding James L. Best Alexander B. Bryk Kalin J. Howell Charles C. Monson Gosia Mahoney Jeffrey Peakall 《Sedimentology》2019,66(1):329-361
Delta fronts are often characterized by high rates of sediment supply that result in unstable slopes and a wide variety of soft‐sediment deformation, including the formation of overpressured and mobile muds that may flow plastically during early burial, potentially forming mud diapirs. The coastal cliffs of County Clare, western Ireland, expose Pennsylvanian (Namurian) delta‐front deposits of the Shannon Basin at large scale and in three dimensions. These deposits include decametre‐scale, internally chaotic mudstone masses that clearly impact the surrounding sedimentary strata. Evidence indicates that these were true mud (unlithified sediment) diapirs that pierced overlying strata. This study documents a well‐exposed ca 20 m tall mud diapir and its impact on the surrounding mouth‐bar deposits of the Tullig Cyclothem. A synsedimentary fault and associated rollover dome, evident from stratal thicknesses and the dip of the beds, define one edge of the diapir. These features are interpreted as recording the reactive rise of the mud diapir in response to extensional faulting along its margin. Above the diapir, heterolithic sandstones and siltstones contain evidence for the creation of localized accommodation, suggesting synsedimentary filling, tilting and erosion of a shallow sag basin accommodated by the progressive collapse of the diapir. Two other diapirs are investigated using three‐dimensional models built from ‘structure from motion’ drone imagery. Both diapirs are interpreted to have grown predominantly through passive rise (downbuilding). Stratal relationships for all three diapirs indicate that they were uncompacted and fluid‐rich mud beds that became mobilized through soft‐sediment deformation during early burial (i.e. <50 m, likely <10 m depth). Each diapir locally controlled the stratigraphic architecture in the shallow subsurface and potentially influenced local palaeocurrents on the delta. The mud diapirs studied herein are distinct from deeper ‘shale diapirs’ that have been inferred from seismic sections worldwide, now largely disputed. 相似文献
13.
晚期泥底辟控制作用导致神狐海域SH5钻位未获水合物的分析 总被引：1，自引：0，他引：1
海底泥底辟构造与天然气水合物成藏关系密切,泥底辟既能为水合物提供充分的气源物质,同时又能促使地层温度场改变进而影响水合物成藏稳定性。南海北部神狐海域SH5站位虽然BSR明显,但钻探证实不存在天然气水合物。该钻位温度剖面异常高,温度场上移,同时在其下伏地层中发现泥底辟构造和裂隙通道。根据上述事实并结合泥底辟发育各个阶段中的特点,认为泥底辟构造对天然气水合物成藏具有控制作用。泥底辟发育早期和中期阶段,低热导率和低热量有机气体有利于天然气水合物生成;而在晚期阶段,高热量液体上侵稳定带底界,导致水合物分解迁移。SH5站位很可能由于受到处于晚期阶段的泥底辟上侵而未能获取天然气水合物。 相似文献
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莺歌海盆地DF1-1底辟断裂系统及其对天然气成藏的控制 总被引：4，自引：1，他引：4
莺歌海盆地的巨厚充填，高地温梯度及大规模的超压流体活动等特殊的地质背景，造就了DF1－1底辟构造的独特性，其内天然气的总体特征与底辟区的断裂系统存在着密切的联系。底辟区内的超压流体活动使其上覆地层产生众多的断裂和裂缝。这些垂向上的断裂和裂隙既构成了异常压力体系能量释放的主要通道。同时也形成了天然气运多的垂向输导体系。在断裂开启过程中上升的活动流体主要取决于断裂下延的深度及断裂上延所连通的中深一浅层的渗透性砂体，因此由断裂与砂体的相互配置所构成的输导体系在DF1－1气田的成藏中起着重要的作用。根据DF1－1的成藏特点，强调断裂系统与天然气运聚的相互促进关系，建立了断裂系统与天然气成藏关系模式。 相似文献
15.
Potash in a salt mushroom at Hormoz Island, Hormoz Strait, Iran 总被引：2，自引：0，他引：2
Increasing volumes of potash are currently being discovered in a cluster of diapirs of Hormoz (formerly Hormuz) salt near Bandar Abbas, Iran. Most of the potash beds studied so far occur in complex recumbent folds in a salt mountain that would be difficult to exploit safely. However, Holocene marine erosion removed any salt mountains from a sub-group of near-shore Zagros diapirs and exposed their deeper structural levels. Even though these diapirs are still active, their potash deposits are likely more tractable to safe exploitation than in a salt mountain — as we make clear here for Hormoz Island.Geochemical surveys on Hormoz Island reveal two separate potash anomalies that are valuable pseudo-stratigraphic markers. Integrating field measurements of the attitudes of bedding with lineaments on air photos suggests that Hormoz Island consists of a mature bell- or plume-shaped mushroom diapir with potash beds wound around a toroidal axis of rotation near current exposure levels.2D numerical models simulate the salt mushroom on Hormoz Island and its internal circulation. They also suggest that the diapir has a wide overhand above a narrow stem in this gas-rich region. We use the mushroom diapir model to outline a regional exploration strategy that has the potential of influencing the world potash market thereafter. 相似文献
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17.
Salt exposures and weathering residuum on several salt diapirs in different geographic/climatic settings were studied. Anhydrite,
gypsum, hematite, calcite, dolomite, quartz, and clay minerals are the main constituents of the weathering residuum covering
the salt diapirs in various thicknesses. Erosion rates of residuum as well as of rock salt exposures were measured at selected
sites for a period of 5 years by plastic pegs as benchmarks. Recorded data were standardized to a horizontal surface and to
long-term mean precipitation. For the rock salt exposures the following long-term denudation rates were determined of 30–40 mm a−1 for coastal diapirs and up to 120 mm a−1 for mountain salt diapirs. Long-term mean superficial denudation rate measured on weathering residuum of low thickness reached
3.5 mm a−1 on coastal diapirs. The total denudation rate estimated for the thin residuum is close to 4–7 mm a−1 based on apparent correlation with the uplift rate on Hormoz and Namakdan diapirs. Denudation of rock salt exposures is much
faster compared to parts of diapirs covered by weathering residuum. The extent of salt exposures is an important factor in
the morphological evolution of salt diapirs as it can inhibit further expansion of the diapir. Salt exposures produce huge
amounts of dissolved and clastic load, thus affecting the surrounding of the diapir. 相似文献
18.
底辟区构造分析及热流体运移模拟——以莺歌海盆地DF1-1为例 总被引：3，自引：0，他引：3
在DF11浅层所发现的与底辟有关的含气构造中 ,天然气的运聚、分布与底辟区的断裂系统和超压 (热 )流体的活动有着密切的联系 ,超压流体的活动不仅为油气的运聚提供了驱动力 ,而且其产生的断裂系统为油气的运移提供了输导路径。文中在分析底辟构造特征的基础上 ,依据连续介质理论 ,采用有限元计算法 ,将固体应力场与流体压力场有机地结合起来 ,对DF11底辟区流体的驱移作用进行模拟。结果显示 :底辟作用引起的应力场决定了底辟区油气沿主要断裂系走向运移的总趋势 ,以底辟体的两侧向其中心运移、自底辟体向上运移为主。热应力控制局部应力场状况及油气运移方向 ,并合理地解释了油气从温度较高的地区向周围温度较低的地区运移的事实 ,其影响力的大小取决于温度应力与构造应力之间的比值 相似文献
19.
Understanding intrasalt structure may elucidate the fundamental kinematics and, ultimately, the mechanics of diapir growth. However, there have been relatively few studies of the internal structure of salt diapirs outside the mining industry because their cores are only partly exposed in the field and poorly imaged on seismic reflection data. This study uses 3D seismic reflection and borehole data from the São Paulo Plateau, Santos Basin, offshore Brazil to document the variability in intrasalt structural style in natural salt diapirs. We document a range of intrasalt structures that record: (i) initial diapir rise; (ii) rise of lower mobile halite through an arched and thinned roof of denser, layered evaporites, and emplacement of an intrasalt sheet or canopy; (iii) formation of synclinal flaps kinematically linked to emplacement of the intrasalt allochthonous bodies; and (iv) diapir squeezing. Most salt walls contain simple internal anticlines. Only a few salt walls contain allochthonous bodies and breakout-related flaps. The latter occur in an area having a density inversion within the autochthonous salt layer, such that upper, anhydrite-rich, layered evaporites are denser than lower, more halite-rich evaporites. We thus interpret that most diapirs rose through simple fold amplification of internal salt stratigraphy but that locally, where a density inversion existed in the autochthonous salt, Rayleigh–Taylor overturn within the growing diapir resulted in the ascent of less dense evaporites into the diapir crest by breaching of the internal anticline. This resulted in the formation of steep salt-ascension zones or feeders and the emplacement of high-level intrasalt allocthonous sheets underlain by breakout-related flaps. Although regional shortening undoubtedly occurred on the São Paulo Plateau during the Late Cretaceous, we suggest this was only partly responsible for the complex intrasalt deformation. We suggest that, although based on the Santos Basin, our kinematic model may be more generally applicable to other salt-bearing sedimentary basins. 相似文献