柴达木盆地北缘石灰沟地区下奥陶统沉积特征

柴达木盆地北缘石灰沟地区下奥陶统石灰沟组主要为一套深灰色至灰黑色页岩夹砾屑灰岩、砂屑灰岩、砂岩及粉砂岩．多泉山组主要为浅灰至深灰色薄层混晶灰岩,顶部有砾屑灰岩。研究表明,其中的暗色页岩主要为斜坡至盆地的深水细粒沉积,砾屑灰岩具有碎屑流沉积的特征．属碎屑流沉积．而砂屑灰岩、砂岩及粉砂岩具有典型的浊流沉积特征．应为浊流沉积;研究区早奥陶世沉积环境主要为广海陆棚、斜坡至盆地边缘．早奥陶世早期到晚期为水体逐渐加深的过程。     

准噶尔盆地南缘安集海河组沉积环境及油气地质意义

根据对准噶尔盆地南缘古近系安集海河组沉积特征、古生态特征研究并结合粘土矿物、微量元素特点认为,该组沉积早期以浅湖环境为主,湖水盐度相对较小;中期湖泊迅速扩大加深,盐度增大,生物群中喜盐分子繁盛并出现海相藻类化石;末期湖盆收缩并迅速淡化.推断安集海河组沉积中期曾经受到古地中海海水的影响,形成半成水环境,介形类中Kassinina.Hemicyprideis等喜盐分子发育,同时出现海相沟鞭藻.高盐度水体易于形成湖底缺氧环境,有利于有机质的保存和转化,也最有利于烃源岩的形成.     

砂岩储集体的地震地学层特征和沉积相分析

本文根据地震地层学原理和沉积特征,对BQZ盆地(BBW盆地、QDN盆地和ZJK盆地的合称)第三系砂岩储集体地震相和沉积相特征进行综合分析,结果在第三系中确定了四种主要砂岩储集体,即三角洲砂体、滨岸砂坝、河道砂体和浊积岩体。这四种砂岩储集体是砂质沉积的主要场所,也是油气聚集的有利相带。可作为进一步寻找非构造油气藏的目标。     

鄂尔多斯盆地周缘延长组露头剖面砂岩组分及地质意义分析

鄂尔多斯盆地周缘延长组露头剖面发育,地层出露齐全,是研究陆相湖盆沉积特征和生油特征的有利地区。该文对周缘延长组露头剖面作了系统采样和测定,显微镜下观察了砂岩碎屑组分,并采用计点法对组分进行了统计。根据碎屑组分与重矿物组合特征,结合盆地内部钻井剖面碎屑组分特征,对延长组物源进行了探讨。研究认为：鄂尔多斯盆地晚三叠世延长组沉积期存在东北、东南、西南、西部、西北及北部等多个不同方向的物源,其中东北、西部和西北物源控制的沉积体系延伸远、分布范围广;不同物源控制沉积体系及同一沉积体系不同沉积期砂岩的碎屑组分、重矿物组合及填隙物成分和组合存在较大差异。综合研究表明,盆地周缘延长组露头剖面砂岩组分特征研究对盆地物源分析和沉积体系划分、砂体展布、有利储层预测、钻井剖面地层对比及井位部署和储层改造均具有重要意义。     

赛汉塔拉凹陷滑塌浊积岩的发现与勘探意义

通过研究二连盆地赛汉塔拉凹陷中洼槽陡坡带的含鲕粒块状细砂岩从岩性特征、沉积结构及构造特征、粒度特征、测井曲线特征、地震反射特征以及对其形成机理的分析,认为赛83x含油砂岩体为在半深湖一深湖环境形成的滑塌浊积扇沉积.这种类型的滑塌浊积扇具备分选、磨圆度、物性较好等条件,尤其是此类砂岩体往往被形成于深湖一半深湖相还原环境的深灰色、灰黑色泥岩--成熟烃源岩所包围,易形成岩性圈闭,有利于油气的运移和聚集成藏,是断陷湖盆陡坡带油气勘探的重要目标.     

鄂尔多斯盆地及邻区中—晚二叠世构造-沉积环境与原型盆地演化

根据钻井、测井、野外露头及地球化学资料，参考盆地周缘构造环境、盆地构造沉降特征及沉积相展布，恢复了鄂尔多斯盆地中—晚二叠世不同时期构造-沉积环境，探讨了盆地性质及演化过程。研究结果表明：(1)中—晚二叠世鄂尔多斯盆地南缘和北缘经历了洋盆俯冲消减过程，以强烈的挤压构造环境为特征，上二叠统石千峰组沉积期盆地北缘古亚洲洋闭合进入陆陆碰撞阶段，盆地内构造沉降速度缓慢。(2)中—晚二叠世鄂尔多斯盆地为大型的克拉通内坳陷盆地，中二叠统石盒子组沉积期基准面呈下降趋势，盆地主体延续山西组沉积期南北高、中部低的古地理格局，南华北地区地势相对更低；周缘隆起区快速抬升且范围逐渐扩大，为坳陷盆地内提供物源，盆地内发育冲积扇、冲积平原、三角洲和浅湖相，向南发育残存潮坪—潟湖，呈南北向展布；晚二叠世基准面趋于稳定，湖相范围扩大，主要发育于盆地南部，潮坪—潟湖环境向南缩小。(3)研究区油气成藏受控于沉积环境，中二叠世发育的陆相三角洲沉积体系有利于形成储集层和盖层，且和下部煤系地层组成中二叠统良好的生-储-盖组合；上二叠统为氧化干旱的古气候，沉积水体较浅，形成的泥岩厚度小，生烃潜力有限，无法形成大规模气藏。     

鄂尔多斯盆地西部延长组碎屑组份变化的讨论

本文根据延长组沉积地质背景应用石英、长石、岩屑类比法将该沉积盆地中砂岩的碎屑成分类型及含量与其潜在的母岩成分进行对比,进一步依其特征来推断分析母岩及物源方向,并论证了大地构造环境和晚三叠世盆地演化对鄂尔多斯盆地延长组组分分区的影响。     

苏北盆地东台拗陷新生代地层地震地层学初步应用

地层岩性油气藏是苏北盆地寻找新生代非构造圈闭油气藏的一种重要类型。文章利用地震地层学的概念,对苏北陆相沉积盆地的新生代地层作了初步应用。1.根据削蚀、顶超、上超、下超标志对苏北盆地东台拗陷新生界进行地震层序的划分和沉积特征的分析。2.对东台拗陷各凹陷整个新生代时期的水体变化作了初步探讨;虽属陆相盆地,其水体升降基本可与全球性海平面升降相对比。3.对各凹陷的阜宁组、戴南组、三垛组地层的主要地震相进行分析和解释,指出浊流河道、三角洲、水下冲积扇、礁滩、地层岩性尖灭和砂岩透镜体的发育。4.明确古水系的分布、流向和沉积相的纵横组合。并指出可能的几种油气藏类型。     

济阳坳陷古近系软沉积变形层中的砂岩脉特征

利用钻井岩心观察、岩石薄片鉴定、油气井测试等手段,对渤海湾盆地济阳坳陷古近系砂岩脉的类型、成因的研究结果表明,济阳坳陷古近系软沉积变形层中的砂岩脉形态复杂,类型多样。根据其形态特征与赋存条件,可分为喉道状砂岩脉、脉络状砂岩脉、飘带状砂岩脉和裂缝充注型砂岩脉4种主要类型。震动流体化作用是形成喉道状砂岩脉的主要成因机制,脉络状砂岩脉和飘带状砂岩脉与震动液化挤压作用有关,裂缝充注型砂岩脉则主要形成于震动拉张裂缝充填作用。对砂岩脉的研究有助于寻找有工业价值的油气藏以及推断古沉积背景和古地震的震级。     

奈曼凹陷白垩系九佛堂组物源分析

为了确定奈曼凹陷白垩系九佛堂组沉积物源及古气候条件,采用薄片鉴定、X射线衍射分析、扫描电镜等手段,对奈曼凹陷白垩系九佛堂组砂岩碎屑及粘土矿物含量变化规律进行了分析,确定了目的层砂岩的岩石学特征及物源特征.研究表明,奈曼凹陷九佛堂组主要沉积于火山带内的局部盆地,沉积物源为侏罗纪东北地区大规模火山喷发所形成的火山岩,沉积具有埋藏快速、物源集中等特征,沉积期古气候较湿润.     

准噶尔盆地南缘深部优质储集层及有利勘探领域

准噶尔盆地南缘深部碎屑岩优质储集层岩性主要为滨岸及三角洲前缘环境沉积的不等粒、中-细粒及极细粒砂岩, 具有成分成熟度及结构成熟度较高、杂基含量低、成岩演化程度较低、固结较弱、储集性能较好的特点, 深部碎屑岩相对优质储集层形成主要与高能沉积环境、长期处于碱性成岩环境、早期长期浅埋-后期快速深埋、异常高压、早期胶结-后期溶蚀等因素有关。南缘第二、第三排构造带为重要的勘探领域, 新近纪、古近纪、白垩纪及晚侏罗世, 沿古湖岸线的滨岸及三角洲前缘的高能环境沉积的有利的储集体是南缘深部重要的勘探目标。     

Incised valley filling deposits: an important pathway system for long-distance hydrocarbon migration—a case study of the Fulaerji Oilfield in the Songliao Basin

In this paper, incised valley filling deposits, which formed an important pathway system for long-distance hydrocarbon migration, are discussed in detail based on core and logging data. The sequence SQy23 of the Cretaceous Yaojia Formation is the main hydrocarbon-bearing layer in the Fulaerji Oilfield. The hydrocarbon source of the oilfield is the Qijia-Gulong Sag which is about 80 km away from the Fulaerji Oilfield. The transport layer of long-distance hydrocarbon migration is the overlapped sandstone complex which fills the incised valley. The incised valley developed during the depositional period from the late Qingshankou Formation to the early Yaojia Formation of Cretaceous （SQqna-SQy0 was about 70 km long and 20 km wide, and extended in the NW-SE direction. The overlapped filling of the incised valley mainly occurred in the expanding system tract of the third-order sequence SQy23 （ESTy23）. Towards the basin, incised valley filling deposits overlapped on the delta developed in the early period, and towards the basin margin, incised valley filling deposits were covered by the shore-shallow lacustrine sandy beach bar developed in the maximum flooding period. All of the delta, the incised valley filling and the shore-shallow sandy beach bar are sandstone-rich, and have high porosity and permeability, and can form an effective hydrocarbon migration and accumulation system. Deltaic sand bodies collected and pumped hydrocarbon from the active source, incised valley filling depositional system completed the long-distance hydrocarbon migration, and lithological traps of shore-shallow lacustrine sandy beach bar accumulated hydrocarbon. The incised valley filling sequences are multi-cycle： an integrated shortterm filling cycle was developed on the erosion surface, and the sequences upward were mud-gravel stone, medium-fine sandstone containing terrigenous gravels and muddy pebbles with cross bedding, silty mudstone with ripple bedding, and mudstone. The incised valley filling deposits are characterized by a strong heterogeneity and the main hydrocarbon migration pathway is the medium-fine sandstone interval.     

焉耆盆地含油气系统的演化

焉耆盆地位于塔里木盆地和吐哈盆地之间,其含油气系统经历了侏罗纪-白垩纪的形成与破坏阶段和第三纪-第四纪的活化与再建阶段。侏罗系水西沟群煤系在八道湾组沉积末时,进入生油门限,标志着焉耆盆地含油气系统的形成。燕山运动中晚期,侏罗系大规模冲隆及剥蚀,侏罗系源岩生烃作用终止,含油气系统被破坏。喜山期,盆地进入挤压阶段,随着第三系沉积厚度的不断加大,侏罗系源岩开始二次生烃,原含油气系统得以活化与重建。由于构造演化不均衡,南部凹陷具有“早期成藏,破坏严重,二次生油范围小,砂体不发育,油气富集程度低”的特点;北部凹陷具有“早期成藏,破坏较弱,二次生烃范围大,砂体发育,油气富集程度较高”的特点。因此,油气勘探时,应注意南、北凹陷的含油气系统特点,区别对待。     

位于巨型走滑断裂端部盆地演化的地质模型——以苏丹穆格莱德盆地为例

横跨非洲大陆中部巨型中非断裂带东端的穆格莱德盆地的演化与周邻的大地构造背景密切相关。在早白垩世的演化与大西洋的分阶段张裂密切相关,晚白垩世的演化与印度块体的快速北移有关,新生代的演化主要和红海的扩张有关。盆地的构造演化可划分三大阶段:在早白垩世盆地发育的鼎盛时期,受中非走滑断裂的影响,盆地沉降速率巨大,沉积中心和沉降中心往往不一致;在晚白垩世,盆地为断陷和坳陷型沉积,沉积中心向远离中非断裂带的东南方向迁移。盆地总体的演化具有从走滑型向拉张伸展型转化的特点。在盆地演化的早期,烃源岩和储集岩在靠近中非走滑断裂带附近较发育;在晚期的构造挤压作用下,一方面对已形成的油气藏进行破坏,同时,可造成油气重新分布,形成一些新生的油气藏。在该部位沉降中心和沉积中心往往不一致,这给油气的勘探带来新的困难,因此对这些地区的勘探要十分慎重。在远离中非断裂带的盆地东南部,是晚期沉积和沉降的中心,主力烃源岩演化比较适中,油气成藏期较晚,是寻找具有工业价值油气田的有利部位。      

LATE CRETACEOUS TECTONIC AND SEDIMENTARY EVOLUTION OF THE BANDAR ABBAS AREA,FARS REGION,SOUTHERN IRAN

The Upper Cretaceous succession in the SE Zagros (Bandar Abbas area) is characterized by marked changes in fades and thickness. These changes relate to sediment deposition in a foreland basin along the NE margin of the Arabian plate. The succession was measured at eight outcrop sections in the Khush, Faraghun, Gahkum, Genow and Khamir anticlines. The measured sections illustrate a transition from shallow‐water carbonate platform deposits (Cenomanian to Coniacian) to deep‐water fades (Santonian to Maastrichtian). Outcrop observations were compared to data from ten off‐ and onshore wells and to a series of seismic profiles. Four cross‐sections were constructed using well and outcrop data and illustrate fades and thickness variations within the Upper Cretaceous. Based on these regional profiles, the Late Cretaceous depositional history of the Bandar Abbas area was reconstructed and can be divided into two tectono‐sedimentary phases suggesting a transition from a passive to an active margin. Sedimentation during Phase I (late Albion to Coniacian) took place in shallow‐water carbonate platform and intrashelf basin settings (Sarvak Formation), and four third‐order sequences can be recognised. The uppermost sequence is locally capped by fresh‐water, pisolith‐bearing carbonate sand and conglomerates with local laterite and palaeosols of the Coniacian Laffan Formation. Shallow‐water facies consist mainly of wackestone to packstones with abundant benthic foraminifera. Sediments deposited in intrashelf basins are dominated by oligosteginid‐bearing fades. Eustatic variations in sea level, the creation of a foreland basin and salt tectonics most probably controlled patterns of sedimentation during this phase. During the second tectono‐sedimentary phase (Phase II: Santonian to Late Maastrichtian), sediments were dominated by pelagic marls and gravity flow deposits. Lateral thickness variations become more marked to the NE as a result of obduction processes and the creation of the foreland basin. Allochthonous ophiolitic and radiolarite‐bearing units are common in the northern part of the Fars region but are restricted to a few localities in the Bandar Abbas area. Traces of allochthonous materials occur in the SE‐most part of the Khush anticline; thrust slices in offshore seismic profiles may link to the Hawasina nappes of Oman. At the top of the Phase II succession, pelagic facies locally interfinger with Omphalocyclus and Loftusia‐bearing fades (Tarbur Formation) and evaporites (Sachun Formation). These deposits are overlain by slumped and dolomitized shallow‐water carbonates of the Paleocene – Eocene Jahrum Formation. The sedimentary sequence in the Bandar Abbas area illustrates a far‐field response to Late Cretaceous obduction processes and foreland basin development, as well as to halokinetic activity. Rapid variations in thickness and fades document the evolution of depositional processes in the foreland basin.     

注水开发油田中河流-三角洲砂岩体的研究

研究砂岩体沉积环境已成为石油地质科学发展的一个重要方面。大庆油田主要油层是在大型内陆湖盆的河流-三角洲环境下沉积的。它包括河道砂岩、分流河道砂岩、河口砂坝砂岩以及三角洲前缘席状砂岩等。     

PETROLOGY, PROVENANCE, AND DEPOSITIONAL ENVIRONMENTS OF THE RESERVOIR SANDSTONES OF OSSU-IZOMBE OILFIELD, IMO STATE, NIGERIA

Upper Eocene immature subarkoses derived from Cretaceous sedimentary rocks, older granites and metamorphic rocks, form the reservoir sandstones of the Ossu-Izombe oilfield, Imo State, Nigeria. These sandstones accumulated as part of a deltaic deposit. The vertical section of deltaic facies consists, from base to top, of a progradational sequence (prodelta and delta front), an aggradational unit (delta plain, marsh and interdistributary bay), and an overlying transgressive shallow marine interval. This sequence was penetrated by nearly all of the 15 wells drilled in the area. Reservoir sandstones are present within the distributary mouth bars, point bars, braided stream deposits, and the shallow marine interval.
Thin section studies, electric-log analyses, and data from modern deltas have aided in establishing the environments of deposition of these sandstone bodies. The principal results of this study are: (1) the basal C sandstone represents distributary mouth bar sands deposited at water depths of about 10 m; (2) the intermediate B group consist of point bar and distributary channel sandstone deposits of the lower delta plain; (3) the A-2 sandstone tops the deltaic cycle as a product of braided streams; and (4) a shallow marine deposit, the A-1.1 and A-1 sandstones, occurs at the top of the deltaic cycle.     

印度河盆地含油气系统特征与成藏模式

印度河盆地是巴基斯坦最大的沉积盆地，油气资源丰富，油气主要聚集在白垩系-下第三系含油气系统中，以气为主。下白垩统Sembar组海相页岩是主要烃源岩，始新统Sui Main石灰岩和下白垩统下Goru组砂岩是盆地内的两套主要储集层，发育岩性、断块、断鼻和背斜等各类圈闭。油气成藏分为两期，早油晚气，早期形成了盆地南部巴丁地区的白垩纪被动裂谷断块油藏，晚期形成始新世石灰岩礁体岩性气藏。研究结果认为：盆地南部印度河三角洲入海处以及邻近海上区域和中西部褶皱带、前渊带是该区下一步寻找油气的主要目标靶区。     

准噶尔盆地白垩系岩相古地理

该文通过露头、钻井、测井、地震等资料,对准噶尔盆地白垩系岩相古地理特征进行了分析。盆地共发育冲积扇、辫状河、冲积平原、三角洲、滨浅湖及半深湖等沉积相。岩性上冲积扇以砂砾岩为主,辫状河以含砾砂岩、中细砂岩为主,三角洲以细砂岩、粉砂岩为主,冲积平原、滨浅湖及半深湖则以泥岩为主;底砾岩层主要发育冲积扇、辫状河及冲积平原沉积。清水河组、呼图壁河组、胜金口组—连木沁组各个沉积时期,均发育三角洲、滨浅湖及半深湖沉积。东沟组沉积时期,辫状河、泛滥平原发育。清水河组、呼图壁河组三角洲砂体为盆地白垩系的有利储层及勘探目标。      

准噶尔盆地石南油气田头屯河组成藏模式

位于准噶尔盆地腹部的石南油气田头屯河组为辫状河沉积,岩性主要为灰褐色岩屑砂岩和褐红色、灰黄色泥岩,砂岩沉积厚度7~26m,属中-低孔隙度、低渗透率储集层。油藏侧向为泥岩遮挡,构造低部位受油水界面控制。研究表明,断裂、不整合对侏罗系上部及白垩系油气运聚具有重要意义,白垩系与侏罗系及侏罗系头屯河组与西山窑组之间的两期不整合面为主要的油气运移通道,局部的正断层起着沟通油源与储集层的作用。