松辽盆地齐家古龙凹陷—三肇凹陷中浅层异常压力系统特征

对研究区千余口单井建立声波时差压实曲线,利用等效深度法计算泥岩超压值,结合DST和RFT实测资料以及地震资料,综合考虑研究区沉积及构造特点,最终揭示了松辽盆地齐家古龙凹陷—三肇凹陷中浅层地层存在4套压力体系,即嫩二段以上的常压体系,嫩江组一段、二段弱超压体系,姚家组常压、低压和弱超压并存体系以及青山口组超压体系。不同层位异常压力分布范围和规模不同,其中青一段最为广泛。产生异常压力的原因复杂:超压形成主要受泥岩欠压实和油气生成控制,嫩江组末期的构造抬升作用是研究区产生异常低压的主要原因,而超压流体流动导致的压力传导作用为压力的再分布提供了有力条件。     

松辽盆地古龙凹陷葡萄花油层超压成因

钻井资料揭示松辽盆地古龙凹陷葡萄花油层存在超压现象,但不存在欠压实现象;葡萄花油层上覆的嫩江组--二段泥岩和下伏的青山口组泥岩存在明显欠压实.声波时差数据计算的泥岩层超压与储层地层测试压力对比,证实油层超压主要来自超压系统内部的压力传递.油气产能与压力测试数据统计表明油层内部原油的热裂解对油层超压也有一定贡献;统计的超压油层的压力梯度大于静水压力梯度,说明储层内存在流动压力,青山口组和嫩江组现今仍在向葡萄花油层提供流体.     

松辽盆地北部热史恢复及烃源岩生烃史

根据镜质体反射率、粘土矿物分析和包裹体测试数据对松辽盆地北部齐家-古龙凹陷、三肇凹陷、黑鱼泡凹陷和双城向斜的古地温进行了研究并恢复了其热历史.它们都是在明水组沉积末期达到最高古地温,从古近纪到现今古地温持续降低.各个凹陷经历的古地温高低顺序依次为：古龙凹陷 >双城向斜 >三肇凹陷 >黑鱼泡凹陷,对应最高古地温为160℃至120℃不等.成烃史研究表明：松辽盆地中-浅层主力烃源岩青山口组-段泥岩随着嫩江组的快速沉积迅速进入生烃阶段,但各地所处成烃阶段不同;齐家-古龙凹陷烃源岩在嫩江组沉积初期进入生油门限,在嫩江组-明水组沉积期为快速生烃期,现为成熟-高熟阶段;双城向斜和三肇凹陷烃源岩在嫩江组沉积中期进入生油门限,于嫩江组-明水组沉积末期为快速生烃期,现为成熟阶段;黑鱼泡凹陷烃源岩在嫩江组沉积期末进入生油门限,于四方台组-明水组沉积期为快速生烃期,现为低熟-成熟阶段.     

用灰色理论预测齐家-古龙凹陷中心线以西油气储量分布

齐家—古龙凹陷是松辽盆地主要油气源区,其中心线以西生排出的油气一部分存留在凹陷内,另一部分向西部斜坡运移。为了预测齐家—古龙凹陷中心线以西部分和西部斜坡区油气储量及其分布,根据研究区油气地质特征和油气田分布特点,建立了距离序列的灰色GM(1,1)模型,预测了油气总储量和该储量在各带中的分布比例。并以此为依据,在利用成因法计算出了油气排运量的基础上,计算了不同聚集系数下的齐家—古龙凹陷中心线以西各带的预测储量分布,根据齐家—古龙凹陷和西部斜坡区油气运聚、保存条件,结合松辽盆地的勘探实践,选择适当的聚集系数,预测了齐家—古龙凹陷西半部最终石油可探明储量为(4.4～6.2)×108t,天然气为(770～1078)×108m3;西部斜坡区最终可探明的石油储量为(1.0～1.3)×108t,天然气为(208.4～291.7)×108m3。     

大民屯凹陷压力场特征及其成因机制探讨

异常地层压力是沉积盆地中的常见现象,其与成烃成藏关系密切。本文以欠压实带的有无、欠压实的幅度大小、持续的深度范围,将大民屯凹陷泥岩压实类型分为4种,即强烈欠压实型、欠压实型、局部欠压实型以及正常压实型。利用测井、地质和钻井资料,运用等效深度法分析了该区现今异常压力的展布特征并探讨了其成因机制。5条超压分布剖面揭示大民屯凹陷的超压体系在凹陷内分布较广泛,纵向上基本可分为上、中、下3套压力体系。①纵向上,上部即Es23段及其以上地层基本为正常压力系统;中部即Es33段为弱超压系统;下部即Es43和Es4地层为强超压系统。②横向上,超压在洼陷中心强烈发育,到斜坡和隆起带渐渐演变为正常压力。压实不均衡和生烃作用是大民屯凹陷超压发育的主要机制。     

陕北斜坡中部泥岩压实特征分析及长7段泥岩古压力恢复

陕北斜坡中部长7段泥岩现今欠压实幅度不是很大,因此长7段烃源岩生成的油气运移动力受到怀疑,但现今的压力特征并不能反映成藏期的压力。首先以鄂尔多斯盆地陕北斜坡中部单井泥岩压实曲线为基础,对该区泥岩压实特征进行了综合研究,结果表明研究区内泥岩压实均由正常压实段和异常压实段构成,虽然欠压实幅度不大,但欠压实现象普遍存在;正常压实趋势具有较好的一致性,地表声波时差值集中在320 μs/m左右;现今压实剖面的异常压实段起始深度由东向西逐渐增大,最大古埋深期异常压实带起始深度则分布在2 250~2 400 m。然后恢复了长7段泥岩古孔隙度,并预测了主力烃源岩层(长7段)成藏期泥岩古地层压力。研究区长7段泥岩在成藏期普遍存在异常高压,南部超压明显,压力系数达1.56,反映了成藏期烃源岩具有较强的排烃动力;古压力值为17～28.5 MPa,古压力系数为1.12～1.56,两者在平面上的分布都呈现出西南部高东北部低的特征,很好地解释了研究区内现今油气的分布特征。该研究成果对下一步油气勘探具有重要的指导意义。     

松辽盆地齐家—古龙凹陷上白垩统嫩江组沉积相地震成像

主要应用地震沉积学方法对松辽盆地齐家—古龙凹陷上白垩统嫩江组沉积体系及沉积相进行地震成像。在一个相对的地质时间范围内,以测井和地震资料相结合进行的三级层序对比为基础,应用可视化属性解释和地层切片等地球物理技术对地下地质体进行精细刻画和解释,以揭示高分辨率储集层沉积体特征。经研究,在齐家—古龙凹陷发育重力流水道、湖底扇和河流三角洲等沉积相。在对该区沉积相地震成像的基础上,探讨了嫩江组沉积体成因及地震地貌样式,揭示了嫩江组发育的典型沉积体的空间展布及河道变迁,指出砂岩主要分布在分流河道、下切谷、河口坝以及滩坝中,为在松辽盆地湖相泥岩中寻找岩性油气藏提供了有利依据。     

松辽盆地嫩江组大型陆相坳陷湖盆湖底水道的发现及其石油地质意义

松辽盆地属于大型陆相中生界含油气盆地,通过高分辨率三维地震资料分析,首次在中央坳陷区大庆长垣嫩江组一段湖相泥岩中发现了发育完整的大型湖底水道系统,该系统由3个主干水道和4个末梢分支水道构成,沿大庆长垣自北向南延伸,水道系统延伸最大直线距离71km,水道最大宽度600m。研究认为该水道系统可能为河流直接入湖而形成,电测解释和岩心观察表明水道砂体具有很好的含油气性。因此,这一水道系统的发现为在松辽盆地中央坳陷区广泛发育的湖相泥岩中寻找油气储层提供了一个新勘探领域,具有极其重要的石油地质意义。     

松辽盆地北部嫩一段泥岩超压形成与演化

利用声波时差随埋深的变化及等效深度法,对松辽盆地北部嫩一段泥岩超压大小、分布特征及形成时期进行了研究。结果表明:目前普遍的超压高值区分布在齐家—古龙凹陷,最大值可达到9 MPa以上;主要形成于明二段沉积时期,之后超压值逐渐增大,在明水组沉积末期和古近系沉积末期曾因T1断裂活动释放,超压值降低。根据超压形成演化过程和源岩生排烃史研究得到:①嫩一段源岩主要排烃期为古近系沉积末期;②嫩一段源岩排出的油气向下"倒灌"运移距离最大可达190 m左右,在大庆长垣、三肇凹陷、齐家—古龙凹陷、龙虎泡阶地和明水阶地等大部分地区均可向下伏萨尔图油层中进行"倒灌"运移,仅在局部地区油气可"倒灌"运移进入葡萄花油层;③超压形成时期早于大量排烃期,对于封闭其油气是有利的;④嫩一段泥岩超压自形成后,虽在明水末期和古近系末期曾发生释放超压降低,但封闭能力逐渐增强至今。这些条件应是松辽盆地北部萨尔图、葡萄花油层油气富集与分布的重要原因。     

北部湾盆地涠西南凹陷超压系统与油气运移

利用地震层速度、声波测井及各种录井资料研究北部湾盆地涠西南凹陷超压系统及油气运移 ,用以指导下一步油气勘探。研究发现主要生烃层段流沙港组二段泥岩的欠压实是形成异常高压的主要原因 ,异常压力主要分布于凹陷中心地区。最大压力封闭点及油的成熟门限深度可以区分异常高压层的作用 ,在生油门限以下的异常压力带中的快速压实段 ,是油气初次运移最有利的层段。研究发现本区存在两种油气运移方式 ,即向泥岩下方运移和侧向运移 ,最后指出勘探油气的有利地区     

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.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)