黄河三角洲表层岩土介质对地震激发频率的影响

黄河三角洲冲积平原覆盖区是胜利油田油气生产的主要区域,随着勘探工作主要由构造勘探转向岩性勘探,由寻找大油气藏到中小型、隐蔽性油气藏,以及各种砂体,这对地震资料的分辨率提出了更高的要求。提高地震波的激发频率是提高分辨率的重要手段,在表层复杂地区如何选取好的激发介质来提高激发频率尤为重要,我们选取时要全面考虑各种因素的影响程度,才能够科学的选取激发条件。     

泌阳凹陷古城东南部岩性圈闭识别方法

泌阳凹陷古城东南部地区构造圈闭具有规模小、幅度低的特点,其油气分布不仅受构造的控制,同时也受到岩性组合等因素的控制。因此,为了更准确地提供钻探目标,查清古城东南部地区岩性圈闭的空间展布特征是十分关键的。以研究区钻井、测井、地震等资料为基础,利用小层沉积微相分析、地震属性分析、等时切片等技术手段对岩性圈闭进行了综合识别和描述。研究表明,该方法在泌阳凹陷古城东南部地区取得了较好的效果。     

地层岩性与地震波速度的关系分析

岩性与地震波速度的关系非常密切,岩石的成分、密度,岩石颗粒的分选、磨圆度等均不同程度地影响着地震波速度。作者在调研的基础上,系统介绍了岩性与地震波速的关系,并给出了5类沉积岩波速和密度的平均值、波速与密度的转换公式、地震岩性预测的方法。     

鄂尔多斯盆地中生界低幅度构造岩性圈闭油气储层预测技术

鄂尔多斯盆地天环向斜中生界油气储层为低幅度构造背景下的砂岩岩性圈闭储层,与围岩波阻抗差小,常规的地震储层预测方法精度低。针对储层的地质地球物理特征,提出了地震地层分析与物性反演的储层预测技术方案,提高了储层预测精度。     

实用地球物理技术在渤中探区岩性勘探中的应用

针对渤中探区Q构造新近系近十年探索没有取得突破性进展,借鉴周边成熟油田浅层岩性勘探的思路,以地质认识为指导,以精细构造解释和岩性圈闭刻画为核心,综合运用地层切片、地震属性分析、90度相移及低幅度构造变速成图等多项地球物理技术,对新近系明下段浅水三角洲岩性圈闭进行精细识别与刻画.结果表明：地层切片结合地震属性技术有效识别砂体平面展布特征,90度相移技术辅助完成砂体精细刻画,低幅度构造变速成图技术真实反映砂体构造特征.通过多项地球物理技术的应用,相继发现了Qa、Qb/c及Qd等一系列浅层岩性含油气构造,掀起了渤海海域浅层岩性勘探的热潮,同时也对相似地质背景探区具有借鉴意义.     

海洋宽频高精度地震处理技术及其深层岩性勘探实践

近海平缆三维地震资料的宽频高精度处理在岩性油气藏勘探中越来越受到重视,但尚缺少专门分析论述。以东海西湖凹陷西斜坡深层精细岩性勘探为目标,通过发展波动方程延拓迭代减法去除鬼波、叠前综合多域去噪、浅水区组合去多次波,以及基于目标体的精细速度建模和偏移成像等技术手段的综合应用及效果分析,建立了海上平缆三维地震资料的宽频高精度处理技术流程,并将其应用于西湖凹陷西斜坡实际资料处理中,实现高分辨率宽频保幅高精度地震处理。利用宽频资料开展深层岩性油气藏的精细描述,有效实现了油气田增储扩边和深层优质岩性气田新发现,以助力海上深层岩性油气藏勘探开发。     

陆丰南珠江组下段#2370层岩性圈闭识别方法

目前，砂岩储层尖灭的判别方法主要是通过针对地震振幅变化和地震属性进行分析，而针对高速灰岩屏蔽影响下砂岩储层尖灭的判别方法研究较少。受灰岩高速、高密度影响，灰岩之下的薄砂岩与围岩的弱反射特征往往被淹没，常规识别方法难以有效判断砂岩的尖灭线形态，影响岩性圈闭的落实。通过三维地震资料分析，提出了一种针对该地区编号为#2370层砂岩尖灭线的地质地球物理综合判别方法，即以统计地震反射特征为主线，以正演模拟为验证，以地震属性和反演为辅助，以地质模式类比为依托，综合刻画砂岩尖灭线。研究结果表明，通过该方法所刻画的砂岩尖灭线与实钻结果基本吻合。同时，结合砂岩尖灭线和局部构造背景，初步落实了该地区南部的#2370层岩性圈闭分布。该方法对灰岩广泛发育地区高速灰岩下岩性圈闭的落实具有重要借鉴意义。     

南黄海新近纪以来地层沉积特征研究的地震技术方法

地震技术方法是研究海底之下地层沉积特征的主要手段。针对地震资料特点和研究需求,开展了新近系以来的沉积特征的地震方法研究,利用资料净化、多次波压制和高分辨率岩性处理等技术方法,提高了地震资料的信噪比和分辨率;采用基于多道地震叠加速度资料基础的速度分析和时间—深度转换方法,保证了沉积地层埋藏深度的计算精度;以海洋地质学、地震地层学的方法为指导,预测地层岩相并评判了沉积环境。CSDP-1孔的钻探结果证明研究方法的有效性。     

三维地震在Q区块侏罗系油气储层精细预测中的应用

针对Q区块侏罗系延安组构造岩性油气藏呈现的河道窄、各向异性强,单单靠井控难以刻画砂岩的展布特征和难以描述低幅度构造的勘探难题。利用三维地震具有良好的横向分辨率、连续性的优势,采用精细层位标定与速度分析、反射结构特征识别和反演等方法,完成了对构造、断裂、储层等成藏因素的精细预测,为井位部署提供有力的技术支撑。     

基于沉积层序理论的高精度层序划分方案及其对岩性圈闭的预测——以珠江口盆地恩平凹陷新近系为例

南海北部珠江口盆地恩平凹陷大面积三维地震资料揭示了新近系类型丰富的砂体，在古珠江三角洲演化及相带迁移的控制下形成了较好的岩性圈闭发育条件。近年来，凹陷内发现的多个构造-岩性圈闭均与河道砂体相关。但在已有的层序地层划分方案中，河道砂体的成因、分类和展布特征与体系域的耦合关系差，砂体发育规律不明，制约了岩性圈闭的勘探效果。基于沉积层序理论，利用大范围井震资料，系统厘定了恩平凹陷珠江组一段-韩江组六段的高精度层序地层框架，并在此基础上开展了精细的三维地震沉积学解剖。分析结果显示，目的层发育的大型辫状河道、小型曲流河道和中型曲流河道，分别与低位、海侵和高位等特定体系域具有密切的耦合发育关系，进而建立了层序格架对河道砂体的有效预测模式，系统指明了凹陷不同区域、不同体系域内岩性圈闭的发育潜力及有利区。本文相关认识对其他海相三角洲盆地岩性圈闭勘探具有启示作用。     

长江三角洲DY03孔磁性地层研究及其意义

长江三角洲地区晚新生代以来接受了大量沉积,长时间序列沉积地层研究对于三角洲沉积环境演化和长江变迁历史都具有重要研究意义。通过对长江三角洲DY03孔古地磁、磁化率以及岩性分析,初步建立了研究钻孔较为可靠的年代地层框架。研究发现,长江三角洲地区沉积序列中有多个具有全球对比意义的短时期磁性漂移事件,对磁性地层定年的进一步应用具有重要意义。分析表明,研究区晚新生代地层中普遍发育的硬黏土层不仅是晚第四纪地层对比的重要标志层,而且对整个晚新生代以来的沉积地层对比都会发挥重要作用。长江三角洲沉积演化基本呈现出早期受构造活动控制,后期受海平面升降和气候变化的制约。     

闽江口水下三角洲的形成与演变──Ⅰ.水下三角洲形成的环境因子与地貌发育

从分析控制或影响闽江口水下三角洲发育的环境因素入手,探讨了闽江口水下三角洲的地貌特征、成因及演变。结果表明,闽江口水下三角洲属于构造-潮控型三角洲,其地貌特征和成因与典型的潮成三角洲既有共同点,也存在着较大的差异。此外,其近期地貌的发育和演变亦受到人类工程活动的重大影响。这些结论可为闽江口航道综合整治工程提供科学理论依据。本文为其第一部分,主要探讨控制或影响闽江口水下三角洲形成的环境因子与地貌发育。     

闽江口水下三角洲的形成与演变 Ⅱ．水下三角洲平原

闽江口水下三角洲的形成与演变全文从分析控制或影响闽江口水下三角洲发育的环境因素、入手,探讨了闽江口水下三角洲的地貌特征、成因及演变。研究结果表明,闽江口水下三角洲属于构造－潮控型三角洲,其地貌特征和成因与典型的潮成三角洲既有共同点,也存在着较大的差异。此外,其近期地貌的发育和演变亦受到人类工程活动的重大影响。这些结论可为闽江口航道综合整治工程提供科学理论依据。本文为其第二部分,主要探讨闽江口水下三角洲平原的地貌特征及演变。     

Cenozoic sedimentary rocks on the northern slopes of the Kuril Deep-Water Basin (Sea of Okhotsk) and conditions of their formation

Sedimentary rocks from the northern slope of the Kuril Deep-Water Basin are examined. Four different-age lithological units are distinguished, and inferences about the probable conditions of their formation are made. The Paleogene-Lower Miocene deposits (lithological units I and II) are represented by the purest varieties of siliceous rocks, which implies their accumulation far away from the source areas under quiet hydrodynamical conditions of the waters. The composition of the microfossils suggests a relatively shallow-water marine basin. The Pliocene-Pleistocene deposits of lithological units III and IV were formed in an active hydrodynamical environment under conditions of synchronous explosive volcanism at bathyal depths. The presence of porcelanite outcrops on the continental slope of the basin, together with the micropaleontological data about the paleodepths of the sedimentation, allows us to assume that, in the region studied, the continental slope was formed as a result of vertical motions in the post-Middle Miocene time.     

Modeling and interpreting the seismic-reflection expression of sandstone in an ancient mass-transport deposit dominated deep-water slope environment

Subsurface mass-transport deposits (MTDs) commonly have a chaotic seismic-reflection response. Synthetic seismic-reflection profiles, created from a precise lithological model, are used to interpret reflection character and depositional geometries at multiple frequencies. The lithological model was created from an outcrop of deep-water lithofacies where sandstone deposition was influenced by mass-transport deposit topography. The influence of MTD topography on sandstone distribution should be considered in reservoir characterization and modeling when MTDs underlie the reservoir, especially if the reservoir is thin relative to the scale of the topography. MTD topography up to several tens of meters in both the horizontal and vertical dimensions (relative to local elevation) compartmentalizes significant quantities of sandstone and is not resolved at lower seismic-reflection frequencies. The resolvability of thick (up to 70 m) sandstone packages is hindered when they are encased in MTDs of at least equivalent thickness. Lateral and vertical changes in seismic-reflection character (e.g., amplitude, polarity, geometry) of sandstone packages in the synthetic profiles are due to lithology changes, tuning effects, resolution limits, and depositional geometries, which are corroborated by the lithological model. Similar reflection-character changes are observed in an actual seismic-reflection profile, of comparable scale to the synthetic profiles, from the Gulf of Mexico, which demonstrates similar lithofacies distributions. Synthetic profiles, when constrained by a precise lithological model, are particularly useful analogues for interpretation of lithofacies relationships, and depositional geometries, in complicated depositional environments, such as deep-water slope deposits.     

东亚和南亚典型大河三角洲晚第四纪地层结构及成因对比

通过整理东亚、南亚典型河口三角洲末次冰消期以来演化历史的研究进展,对比各河口晚第四纪地层结构、沉积体系演替和三角洲开始建造的时间,分析其沉积历史的主要控制因素。结果显示,末次冰消期以来各河口具相似的地层结构和演变过程,即早全新世下切古河谷充填和河口湾发育,中—晚全新世三角洲建造,该过程主要受海平面变化的控制。但是各河口地层结构和沉积历史也存在差异,其中以三角洲开始建造的时间差别最为明显。对比发现这种差异与流域地貌、基岩以及河口沉积盆地的差别有关。流程短、流域基岩易侵蚀的河流,入海泥沙量大,其三角洲开始建造的时间显著早于其他河流,其中以恒河三角洲最为典型。另外,以珠江三角洲为典型,其半封闭、基底浅的河口沉积盆地特征,也有助于中全新世湾顶三角洲的建造。     

Volcanic stratigraphy of DSDP/ODP Hole 395A: An interpretation using well-logging data

Deep Sea Drilling Project/Ocean Drilling Program Hole 395A was drilled approximately 500 m deep into young oceanic crust west of the Mid-Atlantic Ridge. Core recovery is very poor in this hole and therefore continuous downhole measurements are important to understand the drilled lithology. Geophysical downhole measurements were carried out during several cruises. A new set of logs was recorded during Leg 174B in summer 1997. The new logging data show a significant improvement in data quality compared to older measurements from Leg 109. The lithostratigraphy established from cores gives only limited information because of the poor core recovery in this hole. The gaps in the core lithostratigraphy are filled by reconstructing a synthetic lithological profile using the standard well-logging data. Three types of lava morphologies, massive basalts, altered lava flows, and pillow basalts, may be distinguished using the logs because the lava morphologies show differences in their physical properties due to differences in fracturing and alteration. The synthetic lithological profile gives a more detailed and precise vertical definition of single layers than the core profile. The integration of further logging and core data enables a detailed reconstruction of the accretion history at the drill site. Cyclic, upward decreasing trends in the resistivity logs were already observed during earlier cruises and were referred to magmatic cycles. Similar trends occur in the density log and, inversely, in the total gamma ray log. The trends reflect gradual changes in fracturing, porosity, permeability, and alteration and cover depth intervals of several tens of meters. Boundaries between cycles are interpreted to correspond to periods of volcanic quiescence. Two types of boundaries may be identified. Boundaries correlating with reversals in the magnetic field and/or changes in the geochemical composition of the basalts are interpreted as long pauses. Basalts separated by these boundaries were probably fed by separate magma reservoirs. Boundaries identified only by changes in alteration but not in geochemistry are interpreted to represent shorter pauses. They separate basalts that were probably fed by the same magma chamber. This revised version was published online in November 2006 with corrections to the Cover Date.     

Lithological and Geochemical Characteristics of Morpholithogenesis in Buor-Khaya Bay

Oceanology - The paper presents the general lithological and geochemical characteristics of subsea permafrost and thawed bottom sediments from three cores drilled in Buor-Khaya Bay. The...