松辽盆地梨树断陷层序地层格架及沉积体系分布

在层序地层学原理和方法的指导下,综合利用地震、测井、钻井及岩心等资料,结合盆地构造演化特征,建立了梨 树断陷断陷层(晚侏罗世火石岭组及早侏罗世沙河子组、营城组和登娄库组)层序地层格架。将梨树断陷断陷层划分为 1 个一级层序(TSq1)、3 个二级层序 (I—III)、7 个三级层序 (SQ1—SQ7),并在层序格架内进行沉积相划分和沉积体系研究, 明确研究区主要发育冲积扇、扇三角洲、辫状河三角洲、近岸水下扇和湖泊等沉积体系。冲积扇沉积体系主要分布在早期 SQ2 层序中;扇三角洲沉积体系主要分布在 SQ3 和 SQ4 层序中;SQ5,SQ6 和 SQ7 层序则以辫状河三角洲沉积为主;近岸水 下扇沉积体系主要发育在 SQ4、SQ5 和 SQ6 各层序的陡坡带。沉积体系在平面与纵向上的演化受古构造与古地貌的双重控制, 提出梨树断陷 SQ4 和 SQ5 层序沉积砂体为较有利的勘探区域。     

鄂尔多斯盆地北部下奥陶统层序地层学研究

以露头剖面、钻井岩心为研究对象,结合测井地质特征,对鄂尔多斯盆地北部下奥陶统层序界面特征及其成因类型进行了深入研究。将下奥陶统划分为10个三级层序,其中冶里组两个(SQ1,SQ2),亮甲山组两个(SQ3,SQ4),马家沟组一段至马家沟组六段各划分出一个(SQ5—SQ10)。层序SQ1—SQ4都表现为向上变浅的结构特征;层序SQ5—SQ7反映了区域上的海侵过程,总体为潮下环境,以加积序列为特征;层序SQ8反映了区域上的最大海浸,以大量凝缩段沉积为特征。由于加里东运动影响,层序SQ9—SQ10仅在研究区西缘和东南缘出露,西缘以盆地相深水沉积为特征,东南缘以发育潮坪相沉积为特征。     

层序格架下构造—沉积分异对页岩气储层特征的控制——以四川盆地西南部筇竹寺组为例

为明确层序格架下不同构造—沉积分异格局内筇竹寺组富有机质页岩展布特征和页岩气储层差异特征。基于T-R层序模型划分筇竹寺组层序并建立层序地层格架,在层序格架约束下,对筇竹寺组岩心、测井、地球化学及孔隙结构资料进行分析。研究表明,筇竹寺组可识别及划分出4个层序界面与3个三级层序,各层序厚度表现为从绵阳—长宁裂陷的裂陷中心向裂陷外缘逐渐减薄,其中SQ2-RST的厚度在JS1—JY2地区大幅减薄,SQ3厚度减薄范围扩展至Z4—JS1一线。明确了层序格架内不同构造—沉积分异格局下筇竹寺组页岩气储层特征：TOC含量表现为TST大于RST,裂陷中心大于过渡带大于裂陷外缘;矿物含量表现为SQ1和SQ2以长石和石英为主,而SQ3以黏土和石英为主,过渡带的石英和黄铁矿含量高于裂陷外缘;孔隙度表现为过渡带大于裂陷外缘,SQ1低于SQ3和SQ2,且SQ1有机质孔发育较差。绵阳—长宁裂陷的构造—沉积分异作用控制了筇竹寺组沉积时期的地形地貌和水体深度,导致不同层序和构造—沉积分异格局下沉积水体的氧化还原条件、古生产力水平、自生矿物形成环境以及底板封闭性存在差异,并进一步影响了有机质的富集、矿物组分含量和孔隙发育特...     

鄂尔多斯盆地南缘奥陶纪层序地层分析

通过野外实测剖面、钻井、测井资料的研究,识别出8个层序界面,划分出7个三级层序.其中冶里组为SQ1,亮甲山组为SQ2,马家沟组两个(SQ3、SQ4),平凉组两个(SQ5、SQ6),背锅山组一个(SQ7).层序SQ1-SQ6只发育海侵体系域及高位体系域,层序SQ7发育低位体系域及海侵体系域,高位体系域被构造剥蚀.SQ1-...     

塔里木盆地北缘阿克苏地区震旦系露头层序地层研究

本文对塔里木盆地北缘阿克苏地区磷矿沟震旦系剖面进行了详细的沉积体系研究。结果表明,该剖面主要发育滨岸沉积体系、碎屑岩潮坪沉积体系和碳酸盐潮坪沉积体系,这几种沉积体系的组合反映了震旦纪阿克苏地区由碎屑岩体系向碳酸盐岩体系的演化过程。在野外露头中共识别出4种不同类型的层序界面:(1)海侵上超层序不整合界面;(2)水进侵蚀冲刷面;(3)岩性、岩相转换面;(4)暴露溶蚀面。在识别出层序界面的基础上对震旦系划分出2个二级层序和5个三级层序。第一超层序SS1包含3个三级层序:SQ1、SQ2和SQ3。第二超层序SS2包含2个三级层序组:SQ4和SQ5。     

层序地层级次对生物碎屑灰岩沉积演化的控制作用——以中东X油田Mishrif组中下段为例

以中东X油田Mishrif组中下段为例,综合利用地震、测井、岩心、铸体薄片及常规物性等资料,开展层序地层级次识别及层序地层级次对沉积演化的控制作用研究。结果表明：(1)Mishrif组发育5个三级层序和10个四级层序,中下段MB2—MC1层段对应三级层序SQ2—SQ3,包括4个四级层序,其内部发育11个五级层序和多个六级层序。(2)研究区发育次盆地碳酸盐开阔台地-弱镶边台地沉积,储层主要发育于台内滩和台缘滩中,按照生物碎屑类型可将滩相进一步细分为5种类型。(3)六级层序控制单滩体的沉积序列,五级层序控制多滩体的组合特征,四级层序决定沉积微相演化特征,三级层序决定沉积体系的演化特征。(4)SQ2层序的PSS3、PSS4四级层序早期为斜坡环境,发育透镜状滑塌粗粒沉积,后期发育台地边缘滩间→中能滩相沉积序列;SQ3层序的PSS5、PSS6四级层序发育台地边缘滩间→中能滩相→高能滩相沉积序列。SQ3沉积结束后形成了特殊的下切谷充填沉积。     

海拉尔盆地贝尔凹陷贝西地区南屯组层序地层特征

应用沉积学和层序地层学的原理和方法,利用地震、钻井、岩心等资料,结合盆地区域构造演化特征,建立了海拉尔盆地贝尔凹陷贝西地区南屯组层序地层格架,将南屯组划分为1个超层序、4个三级层序、11个体系域。在层序格架内共识别出扇三角洲、辫状河三角洲、湖底扇、湖泊4种主要沉积相类型及8种亚相类型。南屯组沉积时期区内经历了初始沉降-快速沉降-沉降减弱-萎缩的构造演化过程,并形成与其对应的4个三级层序:SQ1沉积时期,研究区为分割的断陷盆地,湖盆规模较小,主要发育扇(辫状河)三角洲;SQ2沉积时期,湖盆规模迅速增大,统一的湖盆基本形成,沉积格局与SQ1时期相似,但有所不同的是区内西南缘出现物源供给,形成扇三角洲沉积;SQ3沉积时期,湖盆规模最大,区内各个物源方向的扇(辫状河)三角洲沉积规模明显减小,湖底扇及滑塌浊积体等重力流深水沉积相对发育;SQ4沉积时期,湖盆萎缩,湖盆规模迅速减小,同时东南部物源供给不足,造成东南部辫状河三角洲沉积几乎消失。生储盖组合及成藏条件综合分析表明:SQ2、SQ3低位体系域及高位体系域发育优质储层,并由于紧邻规模较大的烃源岩,在邻近断裂发育地区易形成断块圈闭及断背斜圈闭;在斜坡地区和缓坡带可形成不整合面作为遮挡的不整合-岩性圈闭及以各类砂体作为储集空间的地层超覆圈闭。     

哈萨克斯坦南图尔盖盆地萨雷布拉克侏罗系沉积层序及其影响因素

哈萨克斯坦南图尔盖盆地受区域构造的影响,侏罗系沉积储层发育演化与构造活动密切相关。在地震、测井及岩芯等资料综合分析的基础上,通过层序地层以及沉积相分析,对南图尔盖盆地A探区萨雷布拉克侏罗系沉积层序特征及其影响因素进行了研究。研究表明:1)南图尔盖盆地A探区侏罗系和白垩系经历了3次较为明显的构造运动,可将研究区的构造演化划分为3个重要阶段:断陷期、断坳转换期及坳陷期,形成了3个二级层序,在二级层序格架内将侏罗系划分7个三级层序;2)早侏罗世断陷期(SQ1、SQ2)主要发育湖泊及辫状河三角洲沉积体系,中侏罗世断坳转换期(SQ3、SQ4)主要发育湖泊及三角洲沉积体系,晚侏罗世坳陷期(SQ5、SQ6、SQ7)主要发育湖泊、三角洲及河流沉积体系;3)通过对研究区沉积层序发育演化影响因素的研究,认为断陷—坳陷的构造演化对沉积层序的发育演化起主要的控制作用。     

梨树断陷七棵树地区沙河子组与营城组层序地层格架及其意义

应用层序地层学理论,综合利用岩芯、测井、地震等资料,建立了梨树断陷七棵树地区下白垩统沙河子组与营城组层序地层格架,并探讨了其与沉积、构造演化的对应关系。结果表明:七棵树地区沙河子组与营城组可以识别出4个三级层序界面和3个最大湖泛面,划分出3个三级层序(SQ1、SQ2、SQ3),每个三级层序又划分为湖侵(TST)和高位(HST)两个沉积体系域;识别出3种沉积相类型:扇三角洲相、辫状河三角洲相和湖泊相。在层序地层格架内,利用钻、测井资料和地震资料对沉积体进行分析,并以此为依据,进一步研究了体系域内沉积相平面展布特征及演化规律,结合现今构造形态,认为有利的油气勘探区主要是东南三角洲体系前缘砂体上倾尖灭形成的岩性—断层复合圈闭,纵向上以SQ1和SQ2层序高位体系域砂体为最优。     

鄂尔多斯东南部上古生界层序地层特征

鄂尔多斯东南部上古生界可区分出的三级层序界面类型包括区域不整合、构造体制转化面、区域海退面、河道下切面、区域(暴露面)、煤层、灰岩底界与地层叠置样式转化面。基于层序界面特征分析,上古生界本澳组至石盒子组可划分为2个二级层序,其中本溪组、太原组和山西组为1个二级层序(SS1),石盒子组整体划归为1个二级层序(SS2)。每个二级层序由区域性的水进-水退旋回组成,为构造控制型层序。二级层序进一步划分为11个三级层序,即本溪组划分出2个三级层序(SQ1和SQ2)、太原组划分出1个三级层序(SQ3)、山西组划分出2个三级层序(SQ4和SQ5)、石盒子组划分出6个三级层序(SQ6-SQ11)。其中SQ1-SQ5为海相及海陆交互相沉积层序,SQ6-SQ11为陆相湖盆沉积层序。基于层序地层特征分析,建立了鄂尔多斯盆地东南部地区层序充填模式,对于沉积体系演化、气藏形成及聚集研究都具有指导性意义。     

南堡凹陷柳赞地区沙三段中下部物源方向对砂岩体展布的控制作用

由于对柳赞地区沙三段物源发育方向认识单一,导致对砂体发育特征和岩性圈闭分布模式的认识与钻探结果不完全相符,从而制约了本区进一步精细勘探挖潜。针对该问题,本文通过进行柳赞地区沙三段中下部层序地层格架分析,重新认识沙三段中下部物源发育特征,建立柳赞地区沙三段中下部砂体发育模式。取得以下4项研究新进展：1） 发现柳赞沙三段中下部地层中层序3底面典型的下超（过去被解释为上超） 地震不整一现象;2） 通过岩心相和地震相分析识别出了近岸水下扇,建立了陡坡带两种储集相模式;3） 利用典型地震相识 别、重矿物分析等技术,发现柳赞地区沙三段沉积早中期由层序1-层序2的东部小型物源演变为层序3北西大型物源,改变了沙三段只发育北东向物源的传统认识;4） 基于对层序地层格架和沉积相发育的研究,建立了柳赞地区沙三段中下部砂岩体发育模式,指明岩性圈闭勘探的重要方向。上述研究新进展不仅对老区挖潜有重要指导意义,而且深化了陆相断陷盆地陡坡带强烈构造运动控制物源迁移和砂岩体分布规律的认识。     

Linked sequence stratigraphy and tectonics in the Sichuan continental foreland basin,Upper Triassic Xujiahe Formation,southwest China

Intracontinental subduction of the South China Block below the North China Block in the Late Triassic resulted in formation of the transpressional Sichuan foreland basin on the South China Block. The Upper Triassic Xujiahe Formation was deposited in this basin and consists of an eastward-tapering wedge of predominantly continental siliciclastic sedimentary rocks that are up to 3.5 km thick in the western foredeep depocenter and thin onto the forebulge and into backbulge depocenters.Five facies associations (A–E) make up the Xujiahe Formation and these are interpreted, respectively, as alluvial fan, transverse and longitudinal braided river, meandering river, overbank or shallow lacustrine, and deltaic deposits. This study establishes a sequence stratigraphic framework for the Xujiahe Formation which is subdivided into four sequences (SQ1, 2, 3 and 4). Sequence boundaries are recognized on the basis of facies-tract dislocations and associated fluvial rejuvenation and incision, and systems tracts are identified based on their constituent facies associations and changes in architectural style and sediment body geometries. Typical sequences consist of early to late transgressive systems tract deposits related to a progressive increase in accommodation and represented by Facies Associations A, B and C that grade upwards into Facies Association D. Regionally extensive and vertically stacked coal seams define maximum accommodation and are overlain by early highstand systems tract deposits represented by Facies Associations D, E and C. Late highstand systems tract deposits are rare because of erosion below sequence boundaries. Sequence development in the Xujiahe Formation is attributed to active and quiescent phases of thrust-loading events and is closely related to the tectonic evolution of the basin. The Sichuan Basin experienced three periods of thrust loading and lithospheric flexure (SQ1, lower SQ2 and SQ3), two periods of stress relaxation and basin widening (upper SQ 2 and SQ3) and one phase of isostatic rebound (SQ4). Paleogeographic reconstruction of the Sichuan Basin in the Late Triassic indicates that the Longmen Mountains to the west, consisting of metamorphic, sedimentary and pre-Neoproterozoic basement granitoid rocks, was the major source of sediment to the foredeep depocenter. Subordinate sediment sources were the Xuefeng Mountains to the east to backbulge depocenters, and the Micang Mountains to the northwest during the late history of the basin. This study has demonstrated the viability of sequence stratigraphic analysis in continental successions in a foreland basin, and the influence of thrust loading on sequence development.     

Sequence subdivision and development characteristics of low-accommodation non-marine basins: a case study of the Yanchang Formation in the Ordos Basin

The third-order sequences of the Yanchang Formation in the Ordos Basin were determined by a comprehensive analysis of surface outcrops, core, logging and seismic data. Natural gamma curves were studied by the band-pass method. The hidden stratigraphic sequence and six lithological cycles were extracted. By examining sequence boundaries and lithological cycles, we identified six third-order (including SQ1, SQ2, SQ3, SQ4, SQ5 and SQ6) and three second-order sequences in the Yanchang Formation. The sequence stratigraphy of the Ordos Basin was found to have the following special development characteristics: (1) the third-order sequence growths were totally stable, and the thickness of the Ordos Basin was relatively stable; (2) thick sand bodies did not form in lowstand systems because of underdeveloped slope breaks; (3) the third-order sequences had diverse features at different sedimentary periods; (4) the distribution of the depositional systems had various characteristics in different tectonic belts, and the entire sequence had the filling characteristics of multiprovenances and multicycles. The low-accommodation Ordos Basin in the Upper Triassic was limited by slow subsidence, gentle basement paleorelief, stable tectonic settings and sufficient sediment supply. The characteristics of the basin included stable developed sequences, limited preserved lowstand systems tracts, multiple depocentres and subsiding centres, development of many delta systems in the north and south of the basin controlled by the gradient of the basement paleorelief, and laterally stretching sediments. Results further indicated that the controlling factors of the third-order stratigraphic sequences of Yanchang Formation in the low-accommodation lacustrine Ordos Basin included sediment supply (provenance), climate and lake-level fluctuation. Overall, our case study indicated that the development characteristics and controlling factors of sequence stratigraphy in a low-accommodation lake basin provided a comprehensive method of establishing the sequence stratigraphic framework of a low-accommodation non-marine basin. Our results also predicted that the SQ3, SQ4 and SQ5 of the Qiaochuan and Zhidan areas favoured oil and gas prospecting of the Yanchang Formation.     

川北中三叠统沉积层序特征及陡坡封闭型镶边台地模式

川北地区中三叠统层序地层学的对比研究表明,雷口坡组顶界面(T2/T1界面)和底界面(T3/T2界面)具有横向分异规律,由此识别出2个Ⅲ级层序,其上部SQ2层序普遍缺失高水位体系域。层序地层格架内的岩相古地理分析表明,该区中三叠世长期处于蒸发台地、局限台地环境,碳酸盐岩颗粒结构欠发育,可见少量藻屑颗粒灰岩和白云岩、细—中晶白云岩,缺少生物礁标志,藻席大量发育,白云石化作用强烈。识别出了工农镇剖面斜坡角砾,并对台地边缘位置进行了厘定。根据沉积及岩石学研究结果,得出了川北地区中三叠统典型的陡坡封闭型镶边台地模式。     

Quantitative simulation on the retrogradational sequence stratigraphic pattern in intra-cratonic basins using physical tank experiment and numerical simulation

A well studied intra-cratonic sedimentary sequence, the Lower Permian Shanxi Formation in the Ordos Basin, northern China, is characterized by a typical back-stepping or source-ward retrogradational stratigraphic stacking pattern and can be used to illustrate the conceptual sequence stratigraphic model developed for intra-cratonic siliciclastic sedimentary basins. Based on the basic geological parameters (initial topography, lake-level curve, and sediment supply) originated from the Lower Permian Shanxi Formation of the Ordos Basin, we simulated quantitatively and validated the source-ward retrogradational sequence stratigraphic pattern of intra-cartonic siliciclastic basin, and demonstrated the use of numerical simulation to replicate and extend a particular flume experiment. In Run 1 (SQ1) the result of numerical simulation was characterized by the fan-shaped distribution, Sequence SQ2 retrograded landwards and overlaid the deposits of Sequence SQ1 after Run 2, and Sequence SQ3 retrograded further landwards and overlaid the deposits of Sequence SQ2 after Run 3. The simulation results indicated that fan-shaped deposits of Sequences SQ1, SQ2, and SQ3 retrograded sequentially landwards. The sediment distribution of three sequences in the numerical simulation is in accordance with the deposits observed in the physical experiment. The simulated sequence stratigraphic pattern of three sequences also matches that from the geological model quite well. The proposed sequence stratigraphic pattern for the intra-cratonic basin should serve as a useful reference for the interpretation of sequence stratigraphic framework and stacking patterns, and the prediction of the distribution of potential reservoir sandbodies within such basins.     

南海北部神狐海域峡谷层序结构差异与控制因素

南海北部陆坡神狐海域峡谷作为我国水合物首次试采区,其沉积层序特征控制和影响着富含水合物沉积体的展布。海域峡谷区沉积作用复杂,影响因素较多,对比难度较大一直是全球深海沉积研究的难题之一。研究采用井震综合分析的方法识别出层序界面,并结合峡谷侵蚀—充填过程,刻画出不同级次的层序界面在空间上的展布。研究划分出6个四级层序,但是各层序内部同相轴发育特征不同：层序Ⅲ和层序Ⅳ的底界可见明显的下切谷和峡谷定向迁移现象,层序Ⅴ和层序Ⅵ层序可见明显的同相轴错断现象。依据层序结构样式存在的差异,将研究区层序类型分成物源驱动型层序和沉降驱动型层序。然后统计层序Ⅰ—Ⅳ内部的沉积参数,根据陆坡滨岸线的演化过程将物源驱动型层序和沉降驱动型层序进行体系域划分。最后将两种类型的层序进行解剖并提出对应的演化模式：物源驱动型层序可以再划分成3个体系域,即低位域、海侵域和高位域,整体物源供给较充足,沟谷侵蚀现象明显,陆坡滨岸线多呈上超结构;沉降驱动型层序划分成4个体系域,即低位域、海侵域、高位域和海退域,其中海退体系域为最大海泛面和峡谷侵蚀面间的规则前积体,层序发育过程伴随断裂沉降,陆坡滨岸线多呈S型结构。     

中寨矿区龙潭组层序划分方法及沉积相特征分析

依据研究区钻孔岩心观察,结合测井及面上区域资料,并通过室内测试分析和野外调查等手段,重点研究区内ZZ808井,运用层序地层学、沉积学等多学科理论。划分了研究区龙潭组层序地层,系统研究了各层序地层特征。结果显示:龙潭组发育4个层序界面,将其划分为3个三级层序,SQ_1属于海相层序,SQ_2、SQ_3属于海陆过渡相层序,六个体系域。层序地层格架的建立分析显示龙潭早期发生脉动式海侵,以慢速海侵,快速海退为特征,沉积主体为障壁砂坝-■湖,沉积相呈北东—南西向展布,主要发育碳酸盐台地相、■湖-潮坪相和障壁沙坝相,含煤厚度自北东—南西逐渐减薄;龙潭晚期为区域性海退过程,发育三角洲相,三角洲成为沉积主体,煤层主要形成于海退—海侵转折期之后。     

东海陆架盆地丽水凹陷丽水36-1构造上古新统物源分析

丽水36-1构造位于东海陆架盆地(台北坳陷)丽水西次凹的中东部，该凹陷属新生代断陷型盆地，呈北东向展布，上古新统灵峰组和明月峰组是主要目的层段。根据该构造已钻3口井进行系统沉积学和测井相研究，上古新统物源主要来自凹陷西部的闽浙隆起带和中部的灵峰凸起带，可能还有北部的雁荡凸起带。不同的物源区通过断层的活动和海平面的升降等控制着沉积体系的发育和展布。在凹陷下陷兴盛和海平面快速上升期，灵峰凸起带物源经过边缘大断层在其西侧形成扇三角洲，进一步向凹陷中心推进形成深水浊积扇和浅海沉积；闽浙隆起带物源可能沿着不同的入口在凹陷西斜坡形成扇三角洲，它们也可进一步向凹陷深处推进形成深水浊积扇体。根据油气聚集规律和物源分析，形成于凹陷深水区的浊积扇沉积和斜坡带的扇三角洲前缘沉积，具有良好的生储盖组合，是有利的勘探目标。     

梨树断陷营城组层序地层格架与沉积相特征

以Vail层序地层学理论为指导,综合利用地震、岩芯、测井及其他资料,通过多种方法,建立了梨树断陷营城组层序地层格架,有力地验证了前人提出的该工区存在4个三级层序的观点,认为由下至上所发育的SQ1~SQ4四个三级层序,分别对应YC1、YC2、YC3、YC4段地层。其中,底部SQ1~SQ3为二分层序,发育湖侵域和湖退域,SQ4为一分层序,仅发育湖侵域。针对研究区目的层段的层序发育特点,在层序地层单元划分和对比的基础之上,对层序格架内的沉积相类型和沉积相展布规律进行了研究,确定研究区主要沉积相类型包括湖泊相、扇三角洲相和辫状河三角洲相等,且沉积砂体具有混源沉积、连片发育的特征。SQ1层序,整个工区发育扇三角洲沉积相;SQ2层序,研究区东部继承发育扇三角洲沉积相,北部则演变为辫状河三角洲沉积相;SQ3、SQ4层序,研究区整体演变为辫状河三角洲沉积相。