鄂尔多斯盆地吴堡地区长6段浊积特征及其石油地质意义     

张伟  刘建朝  高志亮  孙少波 《西安地质学院学报》2012,(2):64-71

在介绍鄂尔多斯盆地吴堡地区延长组长6段沉积特征的基础上,探讨了该储层物性特征、浊积岩特征、浊积岩分布规律及其对油藏的影响,明确了浊流沉积的石油地质意义。结果表明：鄂尔多斯盆地吴堡地区长6段以发育长石砂岩为主,填隙物成分有方解石、绿泥石、白云母以及少量的石英加大、长石加大等,砂岩储集层孔隙结构具有很强的非均质性;吴堡地区长6期湖盆沉降趋于稳定,是三角洲的高建设时期;多水系、多物源的三角洲前缘沉积为深湖浊积扇沉积提供了充足的物质基础;在吴堡地区东北部三角洲前缘水下分流河道前端发育深湖浊积扇沉积,可区分出中心微相和边缘微相两个沉积微相带,其中浊积扇中心微相以细砂岩、粉砂岩与暗色泥岩呈砂泥互层;从平面上看,浊积岩砂体非均质性在侧向上逐渐变弱,砂体底部发育厚度较大、成熟度较高的暗色湖相沉积的烃源岩,深湖相的暗色泥岩含有丰富的烃源岩,而浊积岩砂体是由深湖相的暗色泥岩构成,孔渗物性好的区域易于形成良好的上倾尖灭的透镜状岩性油藏。  相似文献   

准噶尔盆地侏罗系不整合复合体及其岩性地层油气藏     

周新平  徐怀民  王仁冲  刘桠颖  苏芮 《现代地质》2012,26(3):581-588

准噶尔盆地在侏罗纪为一振荡的泛盆,形成了多期不整合,以不整合为层序边界形成的层序地层单元与油气藏的分布富集密切相关。不整合上下的低位域、高位域发育冲积扇、河流、三角洲等储集性能较好的砂砾岩,湖侵域则以厚度稳定、分布广泛的湖相泥岩为主。考虑到准噶尔盆地侏罗系不整合发育的多期性、分布的稳定性以及层序地层单元对生储盖的控制作用,建立由不整合面及不整合面上下的低位域、高位域构成的不整合复合体,多期不整合复合体与湖侵域的泥岩相互叠置形成多套生储盖组合。不整合复合体对于油气的运聚成藏起重要作用,在不整合复合体内部形成多种类型的岩性地层圈闭。不同级别的不整合复合体控制着生、储、盖组合的空间分布与富集层位,不整合复合体内部的组成单元则决定了岩性地层圈闭的类型及分布。其中,不整合复合体的低位域、高位域发育的大型冲积扇、三角洲沉积体系控制岩性圈闭的分布,而不整合复合体内的地层尖灭线控制地层圈闭的分布。  相似文献   

Structural Traps in Detachment Folds: a Case Study from the ‘Comb- and Trough-like’ Deformation Zone/s, East Sichuan, China   总被引：1，自引：0，他引：1  

WANG Zongxiu  ZHANG Jin  LI Tao  ZHOU Xingui  MA Zongjin  TANG Liangjie  XIAO Weifeng  YAN Xili 《《地质学报》英文版》2012,86(4):828-841

Detachment structures occur widely in the crust, and it is the commonest and most important deformation type developed in the region between orogenic belts and basins. The ‘comb-like’ and ‘tough-like’ fold belts in eastern Sichuan are caused by multi-layer detachment. The duplex structure is the most important deformation style in the region, exhibiting different characteristics from typical detachment structures. Different deformation styles, scales, and shortenings resulting from independent deformations of various detachment systems would lead to the phenomenon whereby most of the topographical heights in the region do not correspond to the structural heights in depth. Based on systematic structural analysis and combined with practical oil/gas prospecting, four types of structural traps are described from eastern Sichuan Province, which are: detachment and thrust trap; detachment folding trap; fault-flat blocking trap; and detachment layer trap. Meticulous studies on the deformation and distribution of detachment layers in the eastern Sichuan Province will contribute to oil/gas prospecting and selection of potential regions of marine-origin oil/gas prospecting in South China.  相似文献   

Extreme Case Study of Quay Wall Stability under Earthquake and Tsunami     

Kwang-Ho Lee  Do-Sam Kim 《Marine Georesources & Geotechnology》2013,31(6):504-520

This study was conducted to determine the stability of a quay wall under the combined action of an earthquake and tsunami. Adopting the limit equilibrium method, the stability of the quay wall was assessed for both the sliding and overturning modes under passive and active conditions. The variation in the stability of the quay wall was determined by parametric studies, including those for the tsunami wave height, seismic acceleration coefficient, internal friction angle of soil, wall friction angle, and pore water pressure ratio. The stability of the wall was also compared with the case of no earthquake and tsunami forces. When the earthquake and tsunami were considered simultaneously, the stability of the wall under the passive condition decreased significantly. The critical mode of the quay wall under the earthquake and tsunami forces was found to be that of the overturning mode. In the active condition, the safety factors for sliding and overturning increased, because the tsunami acted as a resisting force. However, it should be noted that, if a tsunami wave spills over the quay wall and then flows backward to the wall active condition, the tsunami no longer acts as a resisting force.  相似文献   

Scaeurgus unicirrhus (Orbigny, 1840) (Cephalopoda,Octopodidae): first record from the South-East Atlantic     

《African Journal of Marine Science》2013,35(1):69-74

The first recorded specimens of Scaeurgus unicirrhus from the South-East Atlantic are described. Five males and two females were captured on the Valdivia Bank, Walvis Ridge, between 24 and 27°S, 400 miles off the Namibian coast. They are compared with specimens caught from other areas, and historical and geographic surveys of the species are made.  相似文献   

Fishing methods for sustainable shrimp fisheries in the Canary Islands (North-West Africa)     

《African Journal of Marine Science》2013,35(3):331-339

During the past 20 years, experimental cruises have been conducted around the Canary Islands (North-West Africa) to investigate the biodiversity of the deep-sea ecosystem and to explore new fisheries resources. Although pandalid shrimps were shown to be very abundant in this region, information is lacking regarding the best fishing method for catching the different species of shrimp. Here, two types of traps were tested, a semi-floating shrimp trap and a traditional bottom trap, in an effort to improve the fishing gear effectiveness and to reduce the capture of non-target species. In total, nine species were captured, which were categorised into three main groups based on their depth of capture: Plesionika edwardsii, P. narval and P. holtuisi (100–400 m); P. ensis, P. martia, P. williamsi and Heterocarpus ensifer (400–800 m); and H. grimaldii and H. laevigatus (800–1 300 m). Significant differences were found in the capture of the different species: P. narval, P. ensis, P. edwardsii and H. ensifer were captured more readily using the semi-floating traps, whereas P. martia, P. williamsi, H. grimaldii and H. laevigatus were caught more efficiently with traditional bottom traps. This intra-specific difference in their capture was considered to be due to the differential motility of the species in the water column. There were indications that P. edwardsii and H. ensifer are an unexploited resource that has the potential to support a viable and sustainable fishery using semi-floating shrimp traps. Furthermore, the deeper-dwelling pandalid shrimps, H. laevigatus and H. grimaldi, could be a secondary target species using bottom traps.  相似文献   

云南个旧卡房中三叠世安尼期变火山岩相序恢复及成矿分析   总被引：2，自引：0，他引：2       下载免费PDF全文

张海  方维萱张贵山甘凤伟魏 宁  郭玉乾 《中国地质》2009,36(6):1322-1330

中三叠世安尼期个旧组卡房段变火山岩恢复为一套碱性基性-超基性岩组合,火山岩-沉积岩岩相组合包括爆发相、喷溢相、火山沉积相、潮坪相、后期盆地流体叠加相、矽卡岩相.垂向相序表现为爆发相→喷溢相→火山沉积相→潮坪相,属于弧后裂谷盆地背景下形成的岩相组合与相序结构.在研究区卡房段可划分为3个期次,进而组成一个旋回,垂直相序特征表明火山活动的多期次性、火山活动由强到弱的变化规律.后期盆地流体叠加相、矽卡岩相作为主要含矿岩相,可以作为今后的找矿指标.  相似文献   

川中须家河组流体包裹体与天然气成藏机理   总被引：1，自引：0，他引：1  

陶士振  邹才能  陶小晚  黄纯虎  张响响  高晓辉  李伟  李国辉 《矿物岩石地球化学通报》2009,28(1)

基于本区构造演化、生烃条件和储集条件及其时空配置的综合分析,根据烃类包裹体形成时间分布的广泛性和离散性,认为须家河组油气充注和聚集成藏是一个持续的过程,主要从晚侏罗世开始持续到古近纪末.天然气成藏时期不是表现为某一或某几个时刻或时期,须家河组煤系烃源岩具有连续生烃、持续充注的特点.根据川中地区的沉积埋藏史,将须家河组的成藏过程分为早期深埋阶段和晚期抬升阶段.深埋阶段(晚侏罗世-晚白垩世)也是成岩圈闭的形成阶段和大量生烃阶段,油气呈层状蒸发式运移,形成"泛气田"(圈闭内气饱和度较低,致密砂岩介质中有一定的分散滞留气,大面积连片砂体普遍含气).构造抬升阶段(白垩纪末-古近纪末)产生断裂和裂缝,烃源岩中的气进一步释放,分流汇聚于孔渗性好的砂体中,形成大面积的"孤立气藏"(圈闭内气饱和度较高,致密砂岩介质滞留分散气较少).须家河组连片砂体与煤系烃源岩互层,生储盖配置得当,天然气成藏是一个持续充注的过程.大范围烃源层和储集层层状间互展布,产状平缓,油气以短距离垂向运移为主,是形成大面积低丰度大气区的主要原因.  相似文献   

延吉盆地油藏上的放射性异常特征   总被引：1，自引：1，他引：0  

刘菁华  王祝文 《吉林大学学报(地球科学版)》2004,34(3):388-392

放射性测量在油藏上的异常特征反映了油藏储层的特征,所以通过放射性测量可以指示油藏的有利位置,为油气资源的勘探与评价提供信息.从延吉盆地进行的瞬时氡气测量、土壤天然热释光测量及伽马能谱测量的综合曲线出发,分析了油藏上、圈闭边缘及外侧的放射性异常特征,从而得出在油层上放时性异常特征为放射性低值,在圈闭边缘以外其放射性异常特征为放射性高值,并通过已知井进行了检正.由此提出可在构造圈闭的有利地段,利用简便的放射性综合测量对延吉盆地的勘探布钻进行指导,从而对延吉盆地的油气资源作出评价.  相似文献   

东准噶尔卡拉麦里断裂带的地质特征及其对中亚地区晚古生代洋陆格局重建的约束   总被引：18，自引：3，他引：15  

李锦轶  杨天南  李亚萍  朱志新 《地质通报》2009,28(12):1817-1826

卡拉麦里断裂带是新疆北部乃至中亚地区一条显著的大型断裂带,是在古生代洋盆关闭以后形成的。对于其前身古洋盆关闭过程中的古洋岩石圈板块的俯冲极性,在地质界有单向俯冲和双向俯冲2种对立的认识,对于该带是否是不同古板块之间的缝合带也存在截然不同的论点。根据２０多年来的研究积累和对前人资料的综合研究,简要地论述了该断裂带及其南侧地区的地质组成和构造变形特征,提出了该带是弧后盆地关闭的遗迹,其南侧为弧后盆地被动边缘,在该弧后盆地关闭的过程中古洋岩石圈板块向北俯冲的论点。最后,简要地探讨了该带对东准噶尔古构造－成矿格局演变和中亚地区古生代洋陆格局重建的制约。  相似文献