Marine hydrocarbon source rocks of the Upper Permian Longtan Formation and their contribution to gas accumulation in the northeastern Sichuan Basin,southwest China     

《Marine and Petroleum Geology》2014

Identification of the main hydrocarbon source rocks of the large Puguang gas field (northeastern Sichuan Basin, southwest China) has been the subject of much discussion in recent years. A key aspect has been the lack of a comprehensive understanding of the development of hydrocarbon source rocks of the Upper Permian Longtan Formation, which had been thought to contain mainly coal seams and thick carbonate layers. In this paper, based on geological data from more than ten wells and outcrops and their related mineralogy and geochemistry, we investigated the depositional environment and main factors controlling organic matter enrichment in the Longtan Formation. We propose a model which combines information on the geological environment and biological changes over time. In the model, organic matter from prolific phytoplankton blooms was deposited in quiescent platform interior sags with rising sea-levels. During the Longtan period, the area from Bazhong to Dazhou was a platform interior sag with relatively deep water and a closed environment, which was controlled by multiple factors including syngenetic fault settling, isolation of submarine uplifts and rising sea-levels leading to water column stratification. Although the bottom water was anoxic, the phytoplankton were able to bloom in the well-lit upper euphotic zone thus giving rise to a set of sapropelic black shales and marlstones containing mostly algal organic matter with minor terrestrial contributions. As a consequence, these rocks have a high hydrocarbon generation potentials and can be classified as high-quality source rocks. The area from Bazhong to Dazhou is a center of hydrocarbon generation, being the main source of reservoired paleo-oils and presently discovered as pyrobitumen in the Puguang gas field. The identification of these source rocks is very important to guide future petroleum exploration in the northeastern Sichuan Basin.  相似文献   

Quantitative characterization of connectivity and conductivity of sandstone carriers during secondary petroleum migration,applied to the Third Member of Eocene Shahejie Formation,Dongying Depression,Eastern China     

《Marine and Petroleum Geology》2014

Studies on migration pathways remain qualitative, albeit extensive quantification of migration forcing. In this study, hydrocarbon carriers are defined as carrier units and their corresponding carrier beds for the Third Member of Eocene Shahejie Formation in the Dongying Depression, Bohai Bay Basin, eastern China, on the basis of their lithofacies and physical properties, spatial relationships, and data availability; secondary migration conduits are then quantified. A carrier unit is defined as a stratigraphic unit that contains microscopically porous and permeable carrier beds and is covered by regional seals. The carrier beds are macroscopically and physically connected to each other within a carrier unit and are hydrodynamically connected during secondary migration. A method of quantifying sandstone carrier units using common physical properties is developed. First, a carrier unit containing potential carrier beds is identified on the basis of lithofacies and their lateral changes. Second, physical connectivity of sandstone carrier beds is assessed on the basis of percolation theory. Third, the hydrodynamic connectivity of a sandstone carrier unit is analyzed using effective parameters that may reflect the hydraulic circulation in the carrier unit. Last, the conductivity of a sandstone carrier bed is quantitatively characterized using appropriate physical property parameters. The results for sandstone carrier units in the Third Member of the Shahejie Formation are used in numerical models addressing Pleistocene secondary migration. The model results explain the discovered accumulation and hydrocarbon shows well; and the model predictions on exploration targets have been confirmed by drilling.  相似文献   

海南铜鼓岭国家级自然保护区海域珊瑚的分布及其健康状况评价   总被引：1，自引：0，他引：1  

李元超  陈海洲  郑新庆  王道儒 《台湾海峡》2014,(4):539-545

沿铜鼓岭国家级自然保护区海岸南北两侧沿岸布设8个站位,采用断面监测法调查了珊瑚的种类多样性、覆盖率、死亡率和补充量等指标,并利用健康指数（CI）评估了铜鼓岭珊瑚礁生态系统的健康状况和遭受环境压力的程度.本次调查共发现铜鼓岭造礁石珊瑚11科23属40种,软珊瑚8种,造礁石珊瑚和软珊瑚覆盖率分别为13.8%和19.4%,该海域珊瑚礁生态系统保存较为完好和健康.铜鼓岭珊瑚的覆盖率呈现明显的空间分布特征,北侧珊瑚覆盖率为0.1%～9.8%之间,远低于南侧的水平（8.1%～66.1%）.从珊瑚补充量来看,铜鼓岭北侧珊瑚的恢复能力基本为零,而铜鼓岭以南的区域可以有0.4个/m^2珊瑚新个体.通过比较2006年以来珊瑚种类、覆盖率、死亡率、补充量、健康指数等方面的调查数据,认为铜鼓岭保护区的珊瑚礁生态系统得到有效保护,珊瑚礁生态系统处于健康状态.  相似文献   

因子分析在海河流域石油类污染综合评价中的应用(英文)     

戴媛媛  宋文平  郑德斌  汪笑宇  尚晓迪  王立平  马超  张阳  孙学亮 《海洋通报(英文版)》2014,(1)

基于因子分析对2012~2013年海河流域pH、DO、COD、BOD5、氨态氮和总石油烃等6项水质指标的监测数据进行统计,并对其中四项指标进行水污染综合指数评估,旨在对海河水质进行较为系统的评价。结果显示,BJ1和HB2两个站位水质属于Ⅳ类标准,其余各站位均为Ⅴ类;各站位综合评价结果得到海河流域指数为1.44,说明海河流域处于污染状态,其污染程度超过该流域功能区的标准。因子分析发现,COD、DO和NH3-N之间差异显著(P0.05);主成分分析显示,除pH和BOD5外,其余指标都在0.70以上;COD、DO、NH3-N和TPH的贡献率较高,其中总石油烃的贡献率为100%,因此可以认为该海域的污染类型属于有机污染,且石油烃污染较为突出。  相似文献   

Ammonites (Phylloceratina,Lytoceratina and Ancyloceratina) and organic-walled dinoflagellate cysts from the Late Barremian in Boljetin,eastern Serbia     

《Cretaceous Research》2014

Late Barremian ammonite fauna from the epipelagic marlstone and marly limestone interbeds of Boljetin Hill (Boljetinsko Brdo) of Danubic Unit (eastern Serbia) is described. The ammonite fauna includes representatives of three suborders (Phylloceratina, Lytoceratina and Ancyloceratina), specifically Hypophylloceras danubiense n. sp., Lepeniceras lepense Rabrenović, Holcophylloceras avrami n. sp., Phyllopachyceras baborense (Coquand), Phyllopachyceras petkovici n. sp., Phyllopachyceras eichwaldi eichwaldi (Karakash), Phyllopachyceras ectocostatum Drushchits, Protetragonites crebrisulcatus (Uhlig), Macroscaphites perforatus Avram, Acantholytoceras cf. subcirculare (Avram), Dissimilites cf. trinodosus (d'Orbigny) and Argvethites? sp. The taxonomic composition and percent abundance of the identified ammonites indicate that their taxa are predominantly confined to the Tethyan realm. Ammonites with smooth and slightly sculptured shells predominate among the studied fauna. The ammonite-bearing succession from Boljetin represents the lower part of the Upper Barremian, ranging in ammonite zonation from the Toxancyloceras vandenheckei Zone to the lower part of the Imerites giraudi Zone. The associated organic-walled dinoflagellate cysts confirm the Late Barremian age of the ammonite-bearing levels.  相似文献   

List of members of the Editorial Board     

《《地质学报》英文版》2014,88(4):VI-VIII

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Estimation of Nash's IUH parameters using stochastic search algorithms     

S. Mohan  D. P. Vijayalakshmi 《水文研究》2008,22(17):3507-3522

In rainfall–runoff studies, it is often necessary to change the duration of a given unit hydrograph. Nash's Instantaneous Unit Hydrograph (IUH) is an ideal method that eliminates the hydrograph duration. This paper presents the results of the application of search algorithms, namely a genetic algorithm and hill climbing, to develop the IUH that minimizes the error between the observed and generated hydrographs. Also the performance of these methods has been compared with that of the classical method used for estimation of IUH, namely the method of moments. The genetic algorithm is a popular search procedure for function optimization that applies the mechanics of natural genetics and natural selection to explore a given search space. Hill climbing is an optimization technique that belongs to the family of local search and algorithms can be used to solve problems that have many solutions, with some solutions better than others. The results obtained from both the genetic algorithm and hill climbing algorithm for estimation of Nash's IUH parameters were compared with the results obtained by the method of moments for storms from two river basins that are located in different climatic regions. It was found that both the genetic algorithm and hill climbing provided improved and consistent results. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

IMU/DGPS数据在1∶50000 DOM生产中的应用     

戴立权  巩淑楠  陈世培  曲平 《地理信息世界》2006,(4)

IMU/DGPS(惯导测量仪/差分全球定位系统)技术航测成图法可直接获取外方位元素,缩短航测成图周期,降低航测成本。通过相应的试验及具体生产的实施,阐明利用该技术获取的控制数据进行1∶50000DOM制作的技术流程及作业过程中出现问题的处理方法。  相似文献   

The Republic of Yemen Petroleum Overview     

《东北亚地学研究》2001,(2)

  相似文献   

鄂尔多斯盆地延长探区低渗致密油气成藏理论进展及勘探实践     

王香增 《地学前缘》2023,30(1):143-155

延长石油集团在鄂尔多斯盆地大力推动石油、天然气、页岩气勘探开发理论研究和技术攻关,多类型资源协同发展,取得显著效果。在石油勘探方面,提出延长组特低渗石油“交替式”成藏理论认识,建立盆地中生界多期差异性成藏新模式,近10年特低渗石油年均探明地质储量超1×10⁸ t。建立细粒沉积风暴、地震等控砂理论,以及甜点预测方法,致密油累计探明地质储量2.1×10⁸ t。针对致密气田砂体成因机理不明、天然气运聚成藏规律不清等主要难题,揭示了“浅水环境岸线频繁迁移控砂”机制,建立了致密砂岩气优质储层成储模式,明确纯石英砂岩和富石英低塑性颗粒岩屑砂岩是致密气分布的“甜点”,形成了基于多要素、全过程天然气运聚模拟的目标优选技术。经勘探实践,发现了延安气田,累计探明天然气地质储量7 635×10⁸ m³。页岩气方面,提出陆相页岩气“三元”成藏富集地质理论的创新认识,认为湖相优质页岩是陆相页岩气富集高产的物质基础,多类型、跨尺度的复杂孔隙网络决定页岩气赋存条件,厚层页岩自封闭能力及高压是保存的关键,实现陆相页岩气产量突破。未...  相似文献