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1.
大庆长垣北部葡萄花上部油层高分辨率层序地层划分   总被引:2,自引:0,他引:2  
应用高分辨率层序地层学以及沉积学相关理论,依据67口井的岩芯和8000口井的测井资料,将松辽盆地大庆长垣北部喇萨杏地区的葡萄花油组上部油层(PI油层)划分为1个受湖泛面限定的完整中期基准面旋回,并在其内部划分出10~14个短期基准面旋回,指出了PI油层在南北向上存在厚度以及短期旋回个数的差异。通过平行及垂直物源方向上的密井剖面分析并结合前人认识以及构造背景,认为葡I油层存在着三种不同的地层叠覆模式:低可容空间下的主动进积薄层叠覆模式;极低可容空间下的强迫进积过路沉积模式;侵蚀进积的叠合模式。该认知对于指导喇萨杏地区甚至整个长垣地区的高精度地层对比具有指导意义。  相似文献   

2.
近岸水下扇沉积体系高精度层序地层学研究   总被引:4,自引:0,他引:4  
以东营凹陷胜北断层下降盘坨85块沙河街组沙三中亚段近岸水下扇沉积体为例,对近岸水下扇沉积体系下的高精度层序地层学进行了研究。经过分析认为,近岸水下扇沉积体系中的高精度层序地层单元划分为准层序组、准层序、层组、层四级,并对准层序和层组的类型和对比方法进行了总结。将近岸水下扇积体系中的层组类型划分为Fu(Fineup)、Cu(Coareseup)和Hu(Homogenicup)三大类,准层序类型划分为Cu-Fu、Cu-Cu、Cu-Hu三大类,同时总结出了沿物源方向的相序递变和垂直物源方向的侵蚀切割对比2种准层序对比模式和侵蚀叠置、相变对比、薄砂层对比、相似渐变等4种层组对比模式。  相似文献   

3.
卫星油田PI层组为该油田的主力油层组,层组内单砂层厚度较薄、空间连续性差。将PI层组纵向上划分为上、中、下3个组合单元,利用地震波形能够给以较好的反映。测井曲线具备好的沉积微相识别能力,将每个单元里存在河道或河坝砂体定义为砂体发育,不存在的定义为互层发育,考察卫星油田三维地震工区近100口井资料识别的沉积微相与地震波形的对应关系,建立8种地震波砂体反射模式,依据模式可有效推测出卫星油田PI层组勘探空白区的砂体发育状况,为该油田部署有利井位提供技术支撑。  相似文献   

4.
谭志远 《地质与勘探》2022,58(4):875-886
通过野外实测剖面和镜下薄片观察,于通过野外实测剖面和镜下薄片观察,在川南柏香田剖面早志留世石牛栏组下部发现一套风暴沉积,具有侵蚀底面、砾屑层、粒序层理、丘-洼状交错层理、沙纹层理以及风暴与平静天气形成的沉积物互层等风暴沉积特征。理想风暴沉积序列由6个沉积单元组成,根据剖面不同沉积单元间的排列组合,将其划分为4种风暴沉积序列,各序列间存在一定继承性,由下向上表现为远源型风暴向近源型风暴的转变、风暴强度逐渐增强的过程。结合更靠扬子东南缘的深水剖面重力流沉积的缺乏,可以推断早志留世石牛栏期研究区的沉积模式为碳酸盐缓坡。结合风暴的形成机制以及石牛栏组风暴沉积的发育特征可知(尤其是正粒序层理和典型丘状交错层理):研究区早志留世处于中低纬度的古地理位置,可为上扬子区古气候及古扬子海盆演化提供依据;上扬子区早志留世同期异相地层存有争议,风暴沉积特征为石牛栏组、小河坝组、罗惹坪组等地层提供等时性对比标尺;川南早志留世石牛栏组沉积环境意见不一,风暴沉积为其碳酸盐岩缓坡环境提供证据资料。通过总结前人对风暴岩物性认识,结合上扬子区同期地层油气地质条件,可提供油气勘探新途径。川南柏香田剖面早志留世石牛栏组下部发现一套风暴沉积,发育侵蚀底面、砾屑层、粒序层理、丘-洼状交错层理、沙纹层理以及风暴与平静天气形成的沉积物互层等风暴沉积特征。理想风暴沉积序列由6个沉积单元组成,根据剖面不同沉积单元间的排列组合,将其划分为4种风暴沉积序列,各序列间存在一定继承性,由下向上表现为远源型风暴向近源型风暴的转变、风暴强度逐渐增强的过程。结合更靠扬子东南缘的深水剖面中重力流沉积的缺乏,可以推断早志留世石牛栏期研究区的沉积模式为碳酸盐缓坡。结合风暴的形成机制以及石牛栏组风暴沉积的发育特征可知(尤其是正粒序层理和典型丘状交错层理):研究区早志留世存于中低纬度的古地理位置,可为上扬子区古气候及古扬子海盆演化提供依据;上扬子区早志留世同期异相地层存有争议,风暴沉积特征为石牛栏组、小河坝组、罗惹坪组等地层提供等时性对比标尺;川南早志留世石牛栏组沉积环境意见不一,风暴沉积为其碳酸盐岩缓坡环境提供证据资料;总结前人对风暴岩物性认识,结合上扬子区同期地层油气地质条件,提供油气勘探新途径。  相似文献   

5.
以松南西斜坡大布苏地区青一段薄层细粒浊积岩地层为例,以高分辨率层序地层学和沉积学理论为指导,建立了五级层序的高精度等时地层格架,并用最大熵频谱分析进行验证。利用岩芯、测井和地震手段,总结了研究区浊积岩的沉积特征及与三角洲前缘沉积相的区别,通过单井、连井以及RMS振幅确定了坡折带的位置及浊积岩沉积分布规律,得出该区浊积岩属于三角洲前缘河口坝远源缓坡滑塌成因,为线物源、砂泥混合型。薄层细粒浊积岩沉积规律研究表明:①滑塌浊积体主要分布于基准面下降期,靠近层序界面,厚度较大,垂向上表现为叠加或与浊积水道呈互层,且向上厚度增大;②上升期浊积水道往往靠近层序界面,厚度较大,表现为“箱状”水道主体,下降期浊积水道靠近湖泛面,厚度较小,表现为“尖指状”水道侧翼;浊积水道随基准面上升厚度减薄,随基准面下降厚度增加;③浊积席状砂主要分布在较深水、最大湖泛面附近,厚度较薄,或表现为垂向上叠加,或与湖相泥岩、浊积水道侧翼及滑塌浊积体呈互层关系。勘探实践表明研究区薄层细粒浊积岩可以获得较高的油气产量。  相似文献   

6.
渤中西环古近系东营组物源转换与沉积充填响应   总被引:1,自引:0,他引:1  
通过砂岩中碎屑锆石U-Pb年龄分析、火山碎屑组分含量变化、地震多属性分析、层序地层格架与沉积充填特征综合分析,认为东二段沉积时期渤中西环的物源供给方式、层序地层格架及沉积充填特征发生明显的变化.东二下段沉积期前,湖盆处于强烈裂陷期,中-深湖相泥岩发育,物源主要为盆地内部的中生代火成岩基底,沉积层序明显受盆内低凸起控制,在盆内低凸起四周发育一系列近源的扇三角洲朵体;东二下段沉积期后,湖盆处于断-坳过渡期,盆内低凸起四周的断裂活动减弱,沉积层序逐渐向盆内低凸起超覆,盆外太古代-元古代变质岩物源供给不断加强,近源的扇三角洲砂体逐渐向远源的辫状河三角洲砂体转化,同时发育宽广的滨浅湖环境.渤中西环古近纪沉积充填过程中,地层样式、沉积模式与物源供给方式的一致性变化,体现了裂陷湖盆充填演化的内在规律,为我国东部裂陷盆地演化及裂陷旋回划分提供了新的线索.  相似文献   

7.
应用330余口井的钻、测井资料,绘制地层对比图与地层厚度图,建立了地层格架,揭示了地层发育情况,并通过砂岩厚度图与百分含量图,描绘了砂体沉积的分布范围.分析结果表明:胜坨油田沙二上亚段沉积时期存在3个主要物源和1个次要物源,3个主要物源分别是来自陈家庄凸起的西北部物源与东北部物源,以及来自青坨子凸起的东部物源;1个次要物源是来自陈家庄凸起的北部物源,在个别小层沉积时发育.各小层砂岩厚度分布情况揭示出研究区内部物源分配过程,即西北部物源区的碎屑物质向东南方向搬运并控制一区的沉积物质展布;东北部物源区的碎屑向西南方向搬运;东部物源区的碎屑向西搬运,来自东北部与东部的物源两者交汇并控制二、三区的沉积物质展布.物源在不同砂组或小层中其位置在一定区域内不断迁移,碎屑物质在盆地内搬运方向也随之发生变化,造成不同时期(小层)来自物源区的沉积物相互叠置.物源也同时受同沉积断层的影响,同沉积断层的走向控制了地层展布与碎屑物质在研究区内的搬运方向.  相似文献   

8.
松辽盆地大布苏地区的斜坡背景与青山口组一段、二段侧向发育的三角洲前缘砂体配合,具备形成构造—岩性圈闭的良好条件。运用高分辨率层序地层分析方法,将研究层段划分为9个砂组。通过沉积微相分析,确定研究区发育三角洲前缘、浊积扇和半深湖等沉积相类型,并进一步识别出分流河道、河口坝、席状砂、浊积水道、浊积席状砂和半深湖泥质沉积等微相类型。以高频层序划分的砂组为单元,分析了各砂组的沉积微相构成与分布特征,指出垂向上高频层序下降半旋回的砂组,河口坝较发育;上升半旋回的砂组,分流河道较发育;青一段、青二段中,下部砂体厚度大,上部砂体厚度薄。平面上砂体呈南西—北东方向展布,西南部三角洲前缘水下分流河道、河口坝、席状砂等砂体发育;东北部以半深湖泥质沉积为主,局部发育浊积扇;砂体向北西斜坡方向的侧向减薄、尖灭明显。研究认为,三角洲前缘砂体与斜坡背景上的鼻状构造背景相互匹配,易于形成构造—岩性圈闭,为研究区最有利的勘探领域;结合地震特征,进一步预测了3个岩性圈闭勘探目标。  相似文献   

9.
鄂尔多斯盆地三叠系延长组发育多套生储盖组合,其中陇东地区是延长组主要的产油区之一。充分利用最新的三维地震资料,结合大量钻井和测井资料,针对研究区广泛发育的前积型地震连续强反射现象,开展地震地层对比划分、沉积演化及砂体展布规律研究。以湖泛期凝缩层对应的地震同相轴作为地层界面的对比标志,将研究区延长组中段划分出7个层序组,表现为震荡性湖退充填沉积特征,沉积单元呈透镜体依次向湖盆中心叠置,每个沉积单元均发育上部三角洲前缘、中部富泥斜坡和下部深水重力流的三段式沉积相组合,砂体主要分布在沉积单元的上部和下部,平面上具有明显的分带特征。本次研究成果与传统等厚地层对比方案存在明显差异,尤其在顺物源方向,单井之间的小层连通性和叠置关系差异较大,其认识更符合震荡性湖退沉积背景,对油田勘探开发更具有指导性。  相似文献   

10.
以高精度三维地震资料为基础,结合深水水道成因机制和水道截面形态特征,将下刚果盆地A区块中新统深水水道分为侵蚀型、侵蚀加积型和加积型三类,并进一步细分为九种亚类。该分类体现了A区块深水水道从近源至远源方向的横向展布特征。从近源至远源,流体动力条件逐渐减弱,水道形态演化过程为限制性-非限制性-限制性-前端朵叶,水道宽深比和弯曲度均逐渐变大。通过对每个三级层序均方根振幅属性图的分析,并结合海平面升降和构造抬升作用,可见刚果扇不断由南向北迁移及向盆地方向进积,层序自下而上并由南向北,整体由加积水道和远端朵叶沉积向侵蚀加积水道和侵蚀水道沉积转变。  相似文献   

11.
敦化盆地北部凹陷古近系珲春组和新近系土门子组共识别出6 个三级层序。通过多道地震统计法提取子波,制作敦参1 井合成记录,完成了层位标定。通过层序地层格架内基于模型的井约束反演得出高分辨率反演数据体,刻画出目的层砂地比和泥岩厚度平面展布特征。砂地比等值线图显示SH1 --ST2 沉积时期物源主要来自凹陷东南侧。在整个新生界沉积时期,主要物源供给方向变化不大,但供给强度逐渐加强。在各层序单元中,砂地比低值区、泥岩厚度高值区、地层厚度高值区与构造沉降高值区基本重合,表明断裂对沉积具有较强的控制作用。泥岩厚度高值区为泥岩的主要发育区域,由于该区主体为半深湖--深湖沉积,因此初步预测该区为烃源岩发育的有利区域。  相似文献   

12.
长江三角洲南汇潮滩沉积速率及其影响因素   总被引:1,自引:1,他引:0  
近100余年来,南汇潮滩尤其是中、高潮滩,以淤涨为主,使岸线迅速向海推进。但潮滩沉积并 非连续,而是以冲、淤相间,长期净淤积的方式进行。潮滩沉积剖面主要由风暴成因的小型层序组成,粗、细 粒交替分别代表风暴与平静天气的产物。潮滩沉积环境的不稳定性使其难以满足两种常用来计算210Pb沉积速率 的方法---CIC (稳定的初始比度) 模型和CRS(稳定的沉降通量) 模型的前提条件。在实验时,如果只选择 代表平静天气沉积的细颗粒层进行210Pb活度分析,则可能得到一组相对符合CIC模型的数据,利用此方法计算 出南汇潮间带环境的平均沉积速率为6.11~6.23 cm/yr。对历史海图数字化建立的数字高程模型(DEM) 分析 表明,中、高潮滩近50余年的平均沉积速率为1.91~2.05cm/yr,不及210Pb沉积速率的一半。造成这种差异的 原因有:(1) DEM法在高程推算过程中使用简单的潮滩纵剖面模型,导致计算的沉积速率偏低;(2)210Pb法受 到沉积过程中强烈的物理混合作用和沉积后的生物扰动、化学迁移作用等影响,使计算的沉积速率偏高。推断 近50余年来,南汇中、高潮滩的沉积速率为4~5cm/yr。  相似文献   

13.
曲鑫  刘财  冯晅  杨庆节  卢勇旭 《世界地质》2013,32(1):114-122
薄层的识别与检测在反射地震学中是一个重要问题。当地下存在薄层或更为复杂地层的情况下,为消除地层内部吸收等因素对薄层识别的影响,本文在积分能谱的基础上提出了加权积分能谱,并通过模型证明了加权积分能谱比未加权积分能谱具有更好的薄层分辨效果,同时结合高分辨率复数道分析方法,证明了x' ( t) 的三瞬参数与d ( t) 褶积的函数具有更高的分辨率。  相似文献   

14.
泥石流沉积相模式   总被引:15,自引:0,他引:15  
崔之久  熊黑钢 《沉积学报》1990,8(3):128-140
共划分泥石流沉积为6种类型或相即A相泥石流层,B相类泥层,C相冲刷层,D相泥流层;E相泥流层,A1相细粒泥石流层。标准的泥石流相模式是从底层的泥层D相开始,往上为A相、C霜。且以C相为沉积间断标志。  相似文献   

15.
以高精度层序地层学理论为指导,通过对岩心、地震、测井、录井以及分析化验等资料的综合研究,重建了松辽盆地大庆长垣杏树岗地区姚家组一段葡萄花油层组葡I332 a—葡Ⅰ11细层单元沉积模式。认为在杏北油田"脉动隆升作用"(所谓脉动是指下伏隆升中心波动迁移现象)是曲流复合带有规律摆动的内在动力因素。在此理论指导下,重建了该区各细层单元沉积微相平面展布模式。平面上在主力油层葡Ⅰ1—Ⅰ3共识别出了2种亚相、14种沉积微相。综合研究认为,杏树岗葡I332 a—葡I22细层属于三角洲上分流平原相,以高弯曲分流河道砂沉积为主,点坝砂相对发育;葡Ⅰ212细层属于三角洲下分流平原相,以低弯曲分流河道砂沉积为主;葡Ⅰ211—葡Ⅰ11细层属于内前缘干枝状三角洲沉积。该区沉积相的精细研究,为该区下一步油气的勘探与开发奠定了基础。  相似文献   

16.
Rhythms in fine-grained sediments have not previously been studied because of their complex depositional cycles and diagenetic changes. Examination of nearly 9000 layers in outcrops, polished slab samples, and thin sections has led to recognition of rhythms in the Middle Ordovician Whitesburg, Blockhouse, and Sevier formations of east Tennessee. Rhythms have been described in four orders based on relative magnitude. First order cycles (basin-fill sequences, hundreds of metres thick)are composed of thinning upward debris-flow sequences and thickening upward turbiditic shale sequences. Second order cycles (multiple sedimentation units, tens of centimetres thick) consist of: (1) thinning upward cycles; (2) symmetrical cycles; (3) thickening upward cycles; (4) minor multiple cycles; (5) uniform cycles; and (6) dubious cycles. Third order cycles (single sedimentation unit, tens of millimetres thick) have thinning upward and asymmetrical cycles. Fourth order portrays the grain-size variations within a single layer of the third order. First order rhythms were controlled by tectonism and progradation of a deep-sea fan system. Second and third order rhythms were controlled by depositional processes, bottom topography, and sediment source. Depositional processes, sediment source, and bioturbation were the dominant controlling factors in the fourth order. A deep-sea fan model is proposed for the fine-grained turbidites in which channels and lobes coexist in the lower fan. The lower fan/mid fan boundary is marked by the presence of a channel cycle near the top of a lobe sequence. The basin plain/lower fan boundary is suggested by the appearance of minor lobe cycles over the non-cyclic basin plain sequence.  相似文献   

17.
笔者在1∶5万区域地质调查的基础上,对塔尔气地区发育的构造形迹进行了较为详细的研究。结果表明:塔尔气地区可划分五个构造层,分别是兴凯期构造层、早加里东期构造层、海西期构造层、燕山期构造层和喜山期构造层。根据构造形迹中面状构造、线状构造及组合特征以及其所显示的动力学标志,对各构造层的局部应力场进行了恢复。其中,兴凯期早期为NE—SW挤压(左行)剪切作用,后期为近SN向挤压;早加里东期应力作用方式应为NW—SE向挤压为主;海西期主要为近SN向挤压作用;燕山期同样为近SN向挤压作用;而喜山期则表现为大规模的差异性升降运动。  相似文献   

18.
An erodible substrate and a sharp slope break affect the dynamics and deposition of long runout landslides. We study the flow evolution of a granular mass (1.5–5.1 l of sand or gravel) released on a bilinear chute, i.e., an incline (between 35 and 66°) followed by a horizontal sector, either sand-free or covered (1–2-cm-thick sand layer). Monitoring the time evolution of the falling mass profiled at 120 Hz, the impact dynamics, erosion of the basal layer, and modes of deposition are studied. The frontal deposition is followed by a backward propagating shock wave at low slope angles (<45°), or by a forward prograding flow at greater angles. Experiments with colored sand layers show a complex sequence of dilation, folding and thrusting within both the collapsing sand flow and the substrate. Experimental results are compared with real rock avalanche data and nearly vertical collapses. The observed increase of the drop height divided by the runout (H/L or Heim’s ratio) with both chute slope angle and thickness of the erodible substrate is explained as an effect of vertical momentum loss at the slope break. Data suggest a complex evolution, different from that of a thin flow basal shear flow. To provide an approximate explanation of the dynamics, three analytical models are proposed. Erosion of a 1-cm-thick substrate is equivalent to 8–12 % increase of the apparent friction coefficient. We simulate the deposition and emplacement over an erodible layer with a FEM arbitrary Lagrangian Eulerian code, and find a remarkable similarity with the time evolution observed in the experiments. 2D models evidence the internal deformation with time; 3D models simulate deposition.  相似文献   

19.
Scientific inquiry into Pleistocene stratigraphy of the Lower Mississippi Valley (LMV) dates to early writings of European naturalists in the late 19th century. By the early 20th century, landscape evolution concepts, stratigraphic models, and regional syntheses had developed for most areas. The 1944 monograph of H.N. Fisk marks the advent of a predictive stratigraphic and landscape evolution model that links form and process to a predominantly glacioeustatic mechanism. The Fiskian model gained widespread acceptance, and decades passed before significant alternate models began to emerge. Revised stratigraphic and geomorphic concepts are presently developing from newly acquired environmental and engineering data. Present scenarios classify Pleistocene outcrop areas into erosional and constructional landscapes, and veneers of eolian, colluvial, fluvial, coastal, and marine origin can drape both types of surfaces.

The southern LMV and adjacent Gulf Coastal Plain (GCP) experienced significant landscape change during the Pleistocene. Late Tertiary (Pliocene?) to Early Pleistocene deposition of the Upland Complex was by streams with a high sand and gravel load relative to its mud load. The regional drainage network and fluvial system behavior was probably significantly different from the modern. Braided stream alluvial fan complexes received sediment from highland source areas adjacent to the LMV and the glaciated mid-continent. It is plausible that part of Upland Complex deposition predates initial glacial advances.

From Early to Middle Pleistocene, an erosional landscape formed during a dissection period that chiefly postdates soil formation on stable landscape positions of the Upland Complex. Slope evolution truncated a regionally extensive geosol in multiple phases, and parts of the erosion surface complex are graded to the oldest preserved constructional alluvial plains in present valleys. Toe and foot slope positions of the erosion surface complex and its correlative alluvial plains are presently delineated as the Intermediate Complex. Constructional landscapes formed at this time are sparsely preserved; Fisk's Montgomery Terrace in the Lower Red River Valley (LRRV) is the best preserved example. Influences on the development of erosion surfaces in the LMV are not well understood; however interactions of relative sea level fall, climate change, and epirogenic crustal movement are plausible factors.

From the latter part of Middle Pleistocene to the Holocene, there was widespread evolution of modern constructional landscapes. Constructional alluviation preserved lithofacies of mixed load, laterally accreting, meandering streams that developed over large areas of the southern LMV to form parts of the Prairie Complex. Lateral planation in valleys and stable rates of upland sediment generation were dominant processes during Prairie Complex deposition.

Pleistocene stratigraphic examples considered important by Fisk are still considered relevant to modern stratigraphic investigators. Presently, Pleistocene units of the southern LMV, the adjacent LRRV, and central GCP can be correlated only by relative stratigraphic relationships. Refined chronostratigraphic and paleoenvironmental models for these areas would help improve the understanding of the geomorphic influences on Quaternary landscape evolution in the region.  相似文献   


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