南海北部深水西区石油地质特征及勘探前景

南海北部深水西区是一个前瞻性的油气勘探新领域,包括神狐隆起西南端、永乐隆起及琼东南盆地中央坳陷带大部分区域,属于南海北部被动人陆边缘的一部分,构造演化上经历了裂陷和裂后两大阶段。本次研究通过对南海北部深水西区及邻区大量地震和钻井资料研究认为,该区不仅具有优越的基本石油地质条件,而且具有有利的成藏条件,其特点为：①三套烃源岩、五大富牛烃凹陷,资源潜力巨大;②陵三段扇三角洲或滨海砂岩与陵二段海侵泥岩储盖组、三亚、梅山滨浅海相砂岩或低位扇砂体与浅海-半深海相泥岩储盖组合、黄流组低位扇砂体与半深海相泥岩付盖组合、梅山组台地边缘礁灰岩与莺黄组深海相泥岩的储盖组合等4套储盖组合;③构造、低他体和礁圈闭成群成带发育;①各种垂向和侧向运移通延发育齐全,存在超压-常压突变模式、超压-常压过渡模式和强超压区的构造与岩性圈闭成藏模式。南海北部深水西区具有与国外获得巨大成功的深水勘探地区类似的石油地质条件,因此,勘探前景良好,资源潜力巨大。但是深水勘探是一个高风险、高技术、高投入的领域,应当“由浅及深,循序渐进”地推动该区深水勘探。     

西非下刚果-刚果扇盆地圈闭类型和分布特征

下刚果-刚果扇盆地位于非洲西海岸,油气资源相当丰富。该盆地属于被动大陆边缘盆地,具有构造演化的阶段性和沉积充填的独特性,从而造成所形成闭的复杂性和多样性。利用IHS(全球油气勘探开发数据库)和C&C(全球油气田类比系统)资料,将下刚果-刚果扇盆地已发现369个油气田的圈闭划分为构造圈闭、构造-岩性圈闭和构造-地层圈闭3个大类及8个亚类。在此基础上,对不同圈闭类型的平面分布和主要发育层位进行了深入分析,从而认为由陆向海和从北向南,圈闭发育的层位由老变新且圈闭类型表现出明显的分带性。最后指出盆地深水区渐新统-中新统发育的浊积水道圈闭和浅水区下白垩统阿尔比阶的背斜构造圈闭和岩性尖灭圈闭是有利的勘探目标。     

琼东南盆地深水区松南低凸起油气复式聚集条件与成藏模式

文章利用钻井、测井、地化以及地震资料,分析研究了南海北部琼东南盆地深水区松南低凸起的油气成藏条件。松南低凸起位于中央坳陷带5大(潜在)富生烃凹陷包围中,烃源充足。中新世早期三亚组大型海底扇、中新世早期—渐新世晚期陵水组生物礁、渐新世早期崖城组扇三角洲—滨海相沉积、前古近系古潜山风化壳等多类型储层发育。生烃凹陷深部沟源断裂、崖城组大型疏导砂体和多条古构造脊构成了本地区主要的垂向+侧向输导体系。多层系多类型大中型构造、构造+岩性圈闭发育。研究表明,多成藏要素的耦合促使松南低凸起成为深水区的独有的复式油气聚集区,其成藏模式为它源-侧向-复式成藏,主要成藏组合是三亚组海底扇、三亚组—陵水组生物礁、前古近系古潜山,成藏主控因素为储层与运移。此结论可为南海北部深水区进一步的勘探提供参考。     

尼日尔三角洲盆地深水沉积体系特征

尼日尔三角洲盆地深水沉积研究是目前世界油气勘探的热点问题之一.通过对三维地震资料、岩心及测井曲线分析,揭示了尼日尔三角洲盆地南部地区新近系深水沉积体系特征.基于不同属性的层序界面识别,研究区划分出SQ1-SQ6共6个三级层序,并建立层序地层格架,进而总结出研究区深水沉积模式.研究区除堆积正常半深海-深海泥岩外,还广泛发育海底扇沉积,海底扇由浊积水道和海底扇朵体组成,其中水道分支少、弯度大,外部形态类似曲流河;朵体平面上成朵叶状分布,可以划分为末端朵体和决口扇朵体.研究区新近系地层自下向上由老到新,相对海平面先下降再上升,SQ1-SQ4层序以海底扇朵体沉积为主,SQ5-SQ6层序以浊积水道沉积为主.      

琼东南盆地西区梅山组海底扇岩相-地球化学特征及源区意义

南海北部琼东南盆地西区乐东-陵水凹陷梅山组海底扇是当前天然气勘探重点领域,通过研究其岩石类型、轻/重矿物与地球化学特征,判断沉积源区性质,为储层评价及预测提供地质基础.结果表明:岩性以细砂岩为主,发育粉、中-粗砂岩,岩石类型为石英砂岩、岩屑石英砂岩、长石岩屑砂岩,重矿物组合表现为磁铁矿+锆石+电气石+白钛矿;由于发育高铁镁质矿物及粘土矿物,泥岩较砂岩SiO₂含量明显低,Fe₂O₃、MgO、CaO、K₂O含量与稀土总量偏高.说明源区富石英、贫钾长石且含有大量粘土矿物,主要为石英质沉积源区,局部为中性火成岩源区,且经历了低-中等程度的风化作用,是再循环沉积而成.      

新疆东准噶尔喀姆斯特晚古生代沉积记录:物源和沉积作用研究

东准噶尔喀姆斯特下泥盆统阿拉比也巴斯他乌组和下石炭统卡姆斯特组代表陆壳增生不同阶段的沉积响应.碎屑岩碎屑组成模式和地球化学分析结果表明阿拉比也巴斯他乌组形成于大洋-活动大陆过渡型构造环境,物源区主要为发育在过渡型地壳之上的岩浆岛弧;卡姆斯特组形成于活动大陆型构造环境,物源区主要为大陆岛弧环境的切割岩浆弧.沉积相、相组合及生物生态等沉积特征显示两组的沉积环境分别为海底斜坡和海底扇中扇-外扇盆地平原.结合区域构造分析和地层对比研究,下泥盆统阿拉比也巴斯他乌组海底斜坡沉积是东准噶尔构造带早泥盆世弧后盆地沉积响应的主要记录,卡姆斯特组海底扇-海底平原沉积则主要记录了东准噶尔复合地体早石炭世晚期弧间残余海盆的沉积响应.两套沉积响应记录的环境演化受控于中亚型造山带复杂的造山作用.     

准噶尔盆地玛湖凹陷东斜坡中二叠统扇三角洲储层特征与成因

准噶尔盆地玛湖凹陷东斜坡区中二叠统下乌尔禾组是区域油气勘探的重要领域,但勘探程度总体较低,成藏规律不明。以单井岩心、镜下薄片、扫描电镜等分析为基础,储层物性分析为辅,结合地震地球物理分析,对下乌尔禾组储层特征与成因进行分析。结果表明,研究区发育扇三角洲沉积体系,进一步可划分出扇三角洲平原、扇三角洲平原-前缘过渡、扇三角洲前缘等亚相。由于近物源区具有多级坡折古地貌形态,沉积相平面展布具较窄的平原亚相及较宽的三角洲前缘亚相,构成了纵向上由SW向NE方向长轴缓坡到短轴陡坡扇三角洲的潜在油气富集区带。扇三角洲前缘是油气富集的主要有利相带,其水下分流河道微相和水下分流河道间湾微相控制了主要的优质储层,加之多种成岩作用的共同影响及优越的鼻状构造圈闭条件,形成多个潜在油气藏富集区,是下步勘探的重点目标。     

下刚果-刚果扇盆地沉积-构造演化与油气勘探领域

摘要：下刚果-刚果扇盆地位于西非海岸,因其富含油气,资源潜力大,长期以来一直引起众多研究者的关注。由于该区盐构造发育,变形复杂,盆地不同地区和不同勘探目的层勘探程度并不均衡,如何全面认识和评价盆地油气资源潜力成为指导下步勘探工作的关键。通过盆地沉积-构造演化特征研究,指出下刚果-刚果扇盆地是由下刚果盆地与刚果扇盆地垂向上叠置、平面上复合所形成的叠合复合型含油气盆地,经历了前裂谷期、陆内裂谷期、陆间裂谷期和被动陆缘期等演化阶段;在构造特征分析基础上,综合考虑油气成藏要素和运聚方式等特点,划分出新生界构造-岩性圈闭、盐上白垩系构造圈闭和盐下白垩系等三个油气勘探领域;通过各勘探领域油气成藏特征等的系统分析,指出了盆地东部陆上-浅水地区是勘探盐上白垩系构造圈闭勘探领域和盐下白垩系勘探领域的有利地区,盆地西部深水-超深水地区是勘探新生界构造-岩性圈闭勘探领域的有利地区。     

辽河坳陷西部高升以北地区湖盆深陷期的沉积特征

辽河坳陷西部凹陷高升以北地区湖盆深陷期经历了初始断陷阶段→快速沉降阶段→稳定沉降阶段→剧烈沉降阶段→短暂回返阶段共5个阶段。湖盆初始断陷阶段,沉积区主要处于中北部,以冲积扇-浊积扇-湖泊沉积为主;湖盆快速沉降阶段,沉积区南扩,以浊积扇-湖泊沉积为主;湖盆稳定沉降阶段,沉积区覆盖了整个研究区,以扇三角洲-浊积扇-湖泊沉积为主;湖盆剧烈沉降阶段以辫状河三角洲-浊积扇-湖泊沉积为主;而当湖盆进入短暂回返阶段时,北部出露地表遭受剥蚀,沉积区南退,以辫状河三角洲-扇三角洲-湖泊沉积为主。湖盆的沉降中心、沉积中心、沉积方式、沉积相类型及其空间配置等均受湖盆演化阶段控制。同时油气储集砂体的发育、油气圈闭类型等也受湖盆演化特点的影响,湖盆陡坡侧易于形成构造圈闭、岩性圈闭和复合圈闭等,缓坡侧则易于形成地层及岩性圈闭。     

河套盆地厚层砂砾岩油藏特征及成藏主控因素:以临河坳陷吉华2X油藏为例

河套盆地为中-新生代叠合盆地,早期钻井仅见到油气显示,未取得实质性突破。吉华2X厚层砂砾岩油藏的发现,展现了该区广阔的勘探前景。为进一步深化河套盆地油气成藏特征认识及明确有利勘探方向,对吉华2X油藏开展精细油藏解剖和成藏主控因素分析。结果表明:吉华2X油藏是受狼山分支断裂控制形成的继承性鼻状构造,储油层为古近系临河组及白垩系固阳组的扇三角洲平原砂体,油藏富集程度高、开发效果好;洼槽区固阳组高排烃动力的成熟烃源岩是吉华2X圈闭富集成藏的必要条件,砂地比极高的扇三角洲相储集体配套继承性发育鼻状构造与畅通无阻的运聚通道是吉华2X圈闭富集成藏的关键。研究结果对指导河套盆地下步油气勘探具有重要的指导和借鉴意义。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an     

PROSPECTING EXPLORATION

正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of