塔巴庙气田储层环境研究

塔巴庙气田储层经历了同生期,成岩期,后生期,表生期和再埋藏期,表生期的岩溶作用对储层贡献最大,此结论已被实钻资料所证实。     

辽河盆地大民屯凹陷沈95区块砂岩储层中钙质夹层研究

钙质夹层是控制剩余油形成与分布的主要因素之一.辽河盆地大民屯凹陷沈95区块钙质夹层十分发育,利用丰富的岩心、测井资料,识别并探讨了钙质夹层的分布规律及成因.研究表明:本区钙质夹层是早期无铁碳酸盐与晚期含铁碳酸盐胶结形成的两期夹层;早期钙质夹层主要分布于泛滥平原亚相、三角洲平原亚相;晚期钙质夹层主要发育于三角洲前缘亚相,且一般位于砂泥岩接触带,厚层砂岩顶底部碳酸盐胶结物较中部高.早期钙质夹层是沉积期、成岩早期,蒸发作用使富钙孔隙水中的钙质沉淀形成的;晚期钙质夹层是在有机酸作用下,Ca2+、Mg2+在烃源岩(泥岩)中溶解,再于储集岩(砂岩)中沉淀形成的.根据夹层的分布规律可以更有效地挖掘剩余油.     

砂金矿地层的“锈板—碳板”构造对自然金的沉淀富集作用

本文根据岳口砂金矿的探井资料,提出了砂金矿金粒再生加大的化学成因模式。及其在“锈板—碳板”中迁移、沉淀富集的机理。诚然,本区砂金矿金的迁移和沉淀富集作用机理不是单一的,也许有多种因素导致金的富集。尽管各含金层中都会存在同生沉淀富集的金粒,但形成砂金矿富矿层的主要机理是表生作用地球化学的机械搬运和化学沉淀再富集。     

高桥地区奥陶系马家沟组马五_(1-2)亚段岩溶作用与孔隙演化

为了解鄂尔多斯盆地高桥地区奥陶系马家沟组马五1-2(Ma51-2)亚段岩溶作用与储层孔隙演化规律,采用岩心观察、铸体薄片及扫描电镜、能谱等测试分析方法进行了研究。结果表明:研究区Ma51-2亚段碳酸盐岩经历了3期古岩溶作用:(准)同生期岩溶、表生期岩溶和埋藏期岩溶。受加里东中、晚期—早海西期构造运动的影响,碳酸盐岩储层先后经历了准同生期成岩、表生期成岩、浅埋藏成岩、中-深埋藏成岩阶段,相应地,孔隙演化经历了原生孔隙形成—缩减期、缝洞发育期、缝洞缩减充填期和裂缝、埋藏溶蚀—充填期4个阶段。     

苏里格气田东区奥陶系马家沟上组合储层特征及主控因素分析

奥陶系顶部马家沟上组合(马五1—马五4)风化壳储层是苏里格气田东区下古生界主要产气储层,其中马五1+2及马五41是该区块的主力产气层。在前人研究成果的基础上,通过岩心观察、室内薄片分析及扫描电镜、阴极发光等测试分析认为:苏里格气田东区马家沟上组合储层岩石类型以含膏粉晶-泥粉晶白云岩为主,储集空间以膏模孔+溶缝为主;储层受沉积、成岩、岩溶古地貌及构造共同控制,沉积-成岩是白云岩储层的主控因素,有利沉积相是储层发育的基础,成岩作用决定了最终储层空间的形成,构造对储层主要起到沟通渗滤作用,而岩溶古地貌从宏观上控制着储集空间的发育程度和天然气储集保存状况。     

中国天然气碳酸盐岩储层形成的成岩模式

碳酸盐岩储层形成和成岩环境密切相关，本文根据我国实际情况将成岩环境划分为海洋、埋藏和表生三种环境。碳酸盐岩储气层的形成主要为白云岩化作用和岩溶作用。对次生孔隙的储集空间成因，提出了白云岩化形成白云岩溶孔的机制。岩溶作用是在地壳抬升的表生环境作用下，碳酸盐岩发生溶解、溶蚀、坍塌等作用的总和。提出了碳酸盐岩储层形成的成岩模式，明确指出在成岩过程中有三次储集层形成，每次伟层的形成，都可形成气田。并论证了储集层形成的地质条件、变化因素、形成时间以及对储层条件评价。     

松辽盆地西南部白垩系姚家组碎屑岩成岩作用与铀成矿

碎屑岩成岩作用过程中铀元素迁移、聚集规律一直是人们关注的热点。文章通过对松辽盆地西南部含矿目的层姚家组碎屑岩成岩作用特征研究,探讨了成岩演化过程中板状铀矿床的形成机理。研究表明,研究区姚家组含矿砂岩主要以岩屑长石砂岩和长石岩屑砂岩为主,成岩作用强度达到中成岩A期,可划分为同生期、早成岩A和B期、中成岩A期和表生成岩期等4个成岩阶段,同时,将成岩演化过程中的铀成矿作用划分为预富集阶段（沉积-同生期）、排铀阶段（早成岩期）、叠加改造作用阶段（表生成岩期）等3个阶段。在沉积-同生期,含矿层段中暗色泥岩发生了铀的强烈预富集作用,其富集的铀可能是铀成矿过程中最主要的铀来源;在早成岩期,压实作用导致铀从高含量暗色泥岩中排泄到邻近砂岩中可能是最重要的成矿作用,铀主要富集在靠近铀源的灰色砂岩中,其成矿流体迁移方向主要是沿垂向上的;在后期表生作用阶段,地表氧化流体对铀矿体产状进行了改造,促使其形成板状矿体。砂岩型铀矿体的产状可能与其铀的来源有着十分密切关系。     

致密碳酸盐岩气藏井位优选技术及其应用——以苏里格气田东区为例

鄂尔多斯盆地下古生界碳酸盐气藏属于岩性-地层圈闭气藏,储层厚度小、非均质性强,开发难度大。为提高气田开发效果,笔者以苏里格气田东区为例,综合应用钻井、测井、地震、试气等动静态资料,通过对沉积相与成岩机理分析、小幅度古构造精细刻画、岩溶古地貌研究,分析白云岩储层的主控因素,明确了天然气高产富集规律及成藏特征,并结合储层地震,综合预测碳酸盐岩致密气藏有利富集区。在综合考虑天然气成藏模式、控制因素及储渗条件等因素的基础上,地质、地震、测井与气藏工程多学科相结合,优选下古气藏井位坐标,形成了适用于苏里格气田东区下古气藏有效开发的井位优选技术。该技术有效提高了下古气藏开发效果,经济效益大,为致密碳酸盐岩气藏高效开发提供了技术指导。     

珠江口盆地西部文昌A油田钙质隔夹层研究

利用岩心、测井、铸体薄片等资料,采用SMI软件地震波形指示反演技术,分析珠江口盆地西部文昌A油田钙质隔夹层的空间结构特征,在此基础上结合开发井构造位置、储层物性及产能探讨钙质隔夹层对油藏开发效果的影响。研究表明:波阻抗对钙质隔夹层预测效果明显,基于波阻抗的地震波形指示反演精度高(可识别0.5 m的钙质隔夹层);研究区目的层段ZJ_2Ⅰ-1砂组发育3套钙质隔夹层,按其垂向位置分为顶钙层、中钙层与底钙层,顶、底钙层的岩性以生物碎屑灰岩为主,形成于海平面高频振荡的超短期反旋回顶部的临滨沙坝中,平面延伸规模大;中钙层的岩性以钙质砂岩为主,形成于基准面上升的超短期正旋回的中部和顶部,中钙层的形成与差异性成岩作用有关,其横向连续性差、分布局限。钙质隔夹层通过影响含水率而间接影响开发效果。研究认为:当底钙层缺失或存在天窗时,若储层物性较好,可以采取提液措施来提高产能;若储层物性较差,则开发效果差。该新认识突破了传统的"底钙层存在天窗就产能低"的观点,可为油田挖潜提供依据。     

礁滩体与建设性成岩作用

礁、礁丘、丘同属碳酸盐建隆,礁、滩是重要勘探目的层。但各自在沉积组分、组构、环境和时空分布,以及油气地质条件上迥然不同,因而无论从理论还是勘探实践上,都有必要将其各成体系划分开来。礁滩自身为好储集岩,当建设性成岩作用叠加后可形成好的储层。碳酸盐岩优质储层形成,主要受沉积微相与建设性成岩作用两大因素控制。前者是基础,并以高能的礁滩相带为最好;后者主要包括破裂、白云石化和溶蚀三大类,并以白云石化或溶蚀为最优,其中的溶蚀分布最广泛、影响最深刻而对优质储层形成起决定性作用。礁滩储层中的古岩溶类型最为丰富多彩,包括同生期、准同生期、表生期和埋藏期热流体岩溶的所有类型,白云岩化礁滩体也不例外。其中,同生-准同生期岩溶的形成机制与礁滩沉积时高频层序旋回向上变浅序列的短暂暴露淋溶有关,表生期岩溶则受控于礁滩沉积后三级层序旋回Ⅰ型界面的暴露淋溶。由此,导致礁滩储层中除了可以也是(碳酸盐岩中)唯一保存原生孔隙外,还发育了次生溶蚀孔洞缝和大型溶洞。礁丘、灰泥丘尤其是丘间洼地中发育高有机质丰度烃源岩;它们自身没有有效的原生孔隙,但岩溶作用可以形成次生孔隙。     

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.)