委内瑞拉矿业投资操作壁垒及安全性分析

委内瑞拉总体上拥有良好资源禀赋、资源可获得性条件优越,对我国国内矿企在委内瑞拉进行矿业投资具有一定的吸引力,但该国矿业投资操作面临诸多壁垒,这给外资企业的投资安全性带来较大风险.本文介绍了委内瑞拉矿产资源概况、矿业管理机构及矿业权类型等内容,分析了在委内瑞拉进行矿业投资的准则与投资操作壁垒,总结了该国矿业投资的总体环境及矿业投资安全性,建议投资企业应审时度势,充分调研,三思而行.     

特立尼达和多巴哥:诺奖得主奈保尔的故国

特立尼达和多巴哥位于加勒比海诸岛的最南端,与委内瑞拉仅隔窄浅的帕里亚湾。1498年,哥伦布第三次远航时抵达这里,见岛上有三座山峰,遂想起圣父、圣子和圣灵,由此将其命名为"特立尼达”,并从帕里亚湾登陆南美大陆。多巴哥意为“烟草”,位于特立尼达的东北面,面积只有后者的1/16,1642年拉脱维亚人率先到此殖民,之后法国、英国殖民者相继来到此地,多巴哥先后易主31次,直到1814年划归英国。     

全球三大富油气前陆盆地油气分布特征对比

波斯湾盆地、东委内瑞拉盆地和西加盆地是全球油气最富集的前陆盆地。根据最新油气地质资料分析,它们的油气分布特征及资源结构存在明显差异。区域上,3个前陆盆地的逆冲褶皱带和前渊一斜坡带均有油气分布,但油气主要分布于前渊一斜坡带。层系上,波斯湾盆地91.0%以上的油气储量分布于被动陆缘层系,而东委内瑞拉盆地和西加盆地的油气则主要富集于前陆盆地层系。波斯湾盆地的油气资源以常规油气为主,而东委内瑞拉盆地和西加盆地则以非常规重油和天然沥青最为富集。区域性盖层与输导体系的配置关系是控制前陆盆地油气资源结构的主要因素。     

委内瑞拉卡拉高莱斯合同区储层沉积微相研究

以岩心分析和大量的测井，地震资料为基础，通过对各种沉积相标的分析，对委内瑞拉卡拉高莱斯合同含油层系的沉积相类型，微相组成以及主要沉积微相的特征进行研究，笔者认为该区海内库莱（Mercure)组和奥菲西纳（Oficina)组为一套海陆过渡环境的三角洲相沉积，储集层主要为三角洲平原分流河道砂体，三角洲前缘水下分流河道及与之同期伴生的河口坝，前缘席状砂砂体，其次，在小层划分，对比的基础上，根据测井，地城和生产动态资料，分析了合同区含油层系100余个小层的沉积微相的平面展布状况及沉积微相在纵向上的演化规律。     

Channel response to gravel mining activities in mountain rivers

The removal of bed material from active river channels usually affects the bed profile of the streambed, causing progressive degradation upstream and downstream of the extraction site. These effects can extend for kilometers affecting hydraulic structures located in the vicinity of the river reach. In this paper, the geomorphic effects of gravel mining are reviewed and summarized. Some cases in Venezuelan streams are presented to illustrate the problem. To describe the processes of erosion and sedimentation in a gravel extraction pit, a recent developed mathematical model for the simulation of flow and sediment transport in gravel-cobble bed streams is applied to a hypothetical case of gravel mining in a river channel. A simple rectangular dredge pit is imposed as initial condition in the channel bed, and changes in bed elevations and grain size distribution of bed material are calculated by using the numerical model. The process of deposition within the pit, and the downstream and upstream migration of the erosion wave are well simulated by the model and closely resemble the phenomena observed in laboratory experiments. The response of the friction coefficient to the changes in flow and bed elevations shows the importance in modeling adequately flow resistance and sediment transport in gravel-cobble bed streams.     

委内瑞拉马拉开波盆地的油气系统

委内瑞拉的石油储量居世界第五位,其西北的马拉开波盆地为西半球乃至世界油气最富的超大型盆地。自1914年以来已累积产油30×109桶,估计最终石油储量为44×109桶。虽为一个成熟盆地,但其剩余储量仍相当于100多个大型油田。1地质背景马拉开波盆地形成于北—北东向线性正断层控制的构造低地或箕状地堑内,于晚侏罗世开始沉积,在早白垩世—古新世发育了一个碎屑-碳酸盐混合台地。在土仑晚期—坎潘期,La Luna组沉积于缺氧的陆棚—斜坡环境,成为南美洲西北主要的烃源岩。加勒比海板块和南美洲板块北缘在晚古新世和早—中始新世的斜向会聚,导致在…     

Characteristics of Large Low-frequency Debris Flow Hazards and Mitigation Strategies

A low-frequency debris flow took place in the north coastal range of Venezuela on Dec. 16, 1999,and scientists all over the world paid attention to this catastrophe. Four characteristics of low-frequency debris hazard are discussed: long return period and extreme catastrophe, special rare triggering factors,difficulty in distinguishing and a series of small hazards subsequent to the catastrophe. Different measures, such as preventing, forecast - warning,engineering, can be used for mitigating and controlling the catastrophe. In engineering practice, it is a key that large silt-trap dams are used to control rare large debris flow. A kind of low dam with cheap cost can be used to replace high dam in developing countries. A planning for controlling debris flow hazard in Cerro Grande stream of Venezuela is presented at the end of this paper.     

血吸虫病在全球流行的趋势

<正>据联合国卫生组织估计全球血吸虫痛流行的76个国家和地区,至少有2亿人感染血吸虫病,有6亿人受感染血吸虫病的威胁,其中85%的血吸虫病人集中在非洲国家,其他流行严重的地区主要有也门和菲律宾的一些岛屿:在中东一些国家流行程度较低;在亚洲血吸虫病流行的地区主要有长江流域、湄公河中游和菲律宾的一些岛屿。在巴西、委内瑞拉等地也还存在血吸虫病流行。