Organic geochemistry of heavy/extra heavy oils from sidewall cores, Lower Lagunillas Member, Tia Juana Field, Maracaibo Basin, Venezuela

The study of 22 oils from sidewall cores taken at different depths in the Lower Lagunillas Member, well LSJ-AB, Tia Juana Field, Maracaibo Lake is presented, with the purpose of predicting the intervals that present the best crude oil quality. Differences were detected in the biodegradation levels of the studied samples, which are correlated with the depth at which the sidewall core was taken. The API gravity was considered for the oils from each sidewall core and it was found that toward the top of the sequence, the oils have an API gravity of 10.6-11.2°, while toward the base part of the sequence, the well produces extra heavy oils with an API gravity that varies between 8.2 and 8.7°.     

渭河流域水利水保措施减水减沙效益初步分析

截止1989年底,渭河流域共有水库361座,塘坝2666座,引水有效灌溉面积40.4万公顷,治理总面积8136km~2,治理度17.1％。以1970年为效益计算起始年,并将全流域划分为18个片,分别采用水文法和水保法计算1970～1989年间各项水利水保措施减水减沙量及综合减水减沙效益。水文法算得的综合减水效益为24.1％,减沙效益为30.6％;水保法算得的结果相应为29.9％和30.8％,两者相近。     

长江中上游地区土壤人渗速率的空间分异研究

利用双套环法对长江中上游水土流失严重区的50个县（市）进行原他测试，对其典型土壤的稳渗速率及其影响因素进行了分析研究。结果表明：土壤稳渗速率在长江中上游地区呈现规律性的地域分异，四川盆地以及毕节地区是稳渗速率高值区，陕南和陇南地区、三峡库区以及丹江口库区足稳渗速率一般区，金沙江下游地区以及湘东赣南红壤丘陵区是稳渗速率低值区；上壤稳渗速率随土类发生有规律变化，黄壤系列土类最大，然后是石灰土、紫色土，红壤系列土类稳渗速率最小；土壤稳渗速率与质量密度呈负相关关系，与孔隙度、大于0．25mm风干土水稳性团粒含量、有机质含量以及粉／粘呈正相关关系。     

Applicability of the flood‐pulse concept in a temperate floodplain river ecosystem: thermal and temporal components

Annual growth increments were calculated for blue catfish (Ictalurus furcatus) and flathead catfish (Pylodictis olivaris) from the lower Mississippi River (LMR) to assess hypothesized relationships between fish growth and floodplain inundation as predicted by the Flood‐Pulse Concept. Variation in catfish growth increment was high for all age classes of both species, and growth increments were not consistently related to various measures of floodplain inundation. However, relationships became stronger, and usually direct, when water temperature was integrated with area and duration of floodplain inundation. Relationships were significant for four of six age classes for blue catfish, a species known to utilize floodplain habitats. Though similar in direction, relationships were weaker for flathead catfish, which is considered a more riverine species. Our results indicate the Flood‐Pulse Concept applies more strongly to temperate floodplain‐river ecosystems when thermal aspects of flood pulses are considered. We recommend that future management of the LMR should consider ways to ‘recouple’ the annual flood and thermal cycles. An adaptive management approach will allow further determination of important processes affecting fisheries production in the LMR. Copyright © 2006 John Wiley & Sons, Ltd.     

新型埽工--笼埽在黄河控导工程中的应用

介绍了新型埽工——笼埽的结构形式、施工方法，其优点为：(1)克服传统埽工施工工序复杂、速度慢、效率低的缺点；(2)笼埽可工厂化生产，减少现场作业工序和作业面后移；(3)充分利用大型施工机械进行大体积单个笼埽结合机械化施工，作埽速度快、强度高；(4)减少柳料用量，利于环境保护．结合在兰考蔡集控导工程水中进占工程中的应用，从施工准备、机械配合与人员安排及施工流程等方面对笼埽施工技术作进一步说明，并总结了施工注意事项．最后，进行了效益评价并提出了扩大技术应用范围和进行水槽实验的完善思路．     

昆2井优快钻井及油气层保护技术

昆2井是一口位于柴北缘西段的昆特依凹陷潜伏Ⅰ号圈闭上的风险探井,设计井深为5950m。针对柴北缘深探井存在的主要技术难题,制定了昆2井的技术对策。通过对钻井设备的优选、井身结构的优化、钻头及钻具组合的优选、钻井参数及钻井液性能的优化、油气层保护技术的研究与应用,形成了一套适合于柴北缘的优快钻井技术,使昆2井的完钻井深达到5950m。与邻区的深探井平均水平相比,在井深增加888m、大尺寸井眼段更长的前提下,昆2井的钻井、完井周期分别缩短了98.75d、124.2d,钻机月速度增加了317m/台,平均机械钻速增加了0.82m/h。根据“理想充填新理论”,确定了保护油气层的最优复配暂堵方案,利用该方案所配制的钻井液其渗透率恢复值达到了87.5%以上,流变性能良好,滤失量低,对改善泥饼质量、增强井壁稳定性有明显的效果。     

准噶尔盆地三台-北三台地区第三系勘探潜力分析

从沉积及储层组合、油气运移系统等方面全面剖析了准噶尔盆地三台-北三台地区第三系油气成藏条件，建立了成藏模式，对未钻探区勘探潜力进行了预测；通过分析，认为该区第三系储层物性主体差，断裂更多地表现为封闭性，导致沟通深部油气源的运移体系不畅，致使第三系圈闭不能有效捕获和储集油气。圈闭又比较匮乏，主体勘探潜力不大。北25井西背斜紧邻多期活动的甘诃子北断裂，第三系可能发育较好的储层，相对有利，北25井西背斜应是钻探第三系的首选目标。     

塔里木盆地塔河油区原油生物标志化合物在运移方面的应用探讨

塔河油区奥陶系原油的成熟度较高,且受生物严重降解.不同的生物标志化合物成熟度参数仅对有机质生成原油的不同阶段起到标尺作用,需优选既能较好地抗生物降解且适用于较宽的成熟度范围的指标来分析塔河油气运移的可能途径.三环萜烷/17α(H)-藿烷、重排甾烷/规则甾烷及Ts/(Ts+Tm)的比值是比较适用于塔河油区这种特殊性质的原油的生物标志化合物.根据研究,奥陶系原油油气存在两个注入通道,早期主要是由南向北方向运移,油气成熟度相对较低,成藏较早;晚期由东向西运移,原油成熟度相对于早期的较高,原油成藏稍晚.     

生烃化学动力学在川东北普光气田的应用

普光气田是四川盆地近期发现的规模最大、埋藏最深、资源丰度最高的气田。通过认识普光气田各个烃源岩层的贡献量、生烃关键期与构造演化的关系、油气成藏具体模式等，建立生烃化学动力学模型、标定参数，结合地区烃源岩参数和地史、热史资料，定量描述该地区的生烃过程及油裂解成气过程。认为：普光地区的主力烃源岩为下志留统泥岩；主要干酪根生油期为早二叠世末到早三叠世末期（距今286Ma至240Ma）；主要干酪根生气期为中三叠世（距今240Ma至230Ma）；主要气源是原油后期热裂解气，原油裂解成气的时间比较晚，主要油裂解成气期为早白垩世（距今144Ma至97．5Ma），从而决定了普光气田的成藏模式为“多期成藏，油气转化，晚期定位”。图2表3参33     

Treatment of Natural Geometry in Finite Volume River Flow Computations

A method is proposed for the treatment of irregular bathymetry in one-dimensional finite volume computations of open-channel flow. The strategy adopted is based on a reformulation of the Saint-Venant equations. In contrast with the usual treatment of topography effects as source terms, the method accounts for slope and nonprismaticity by modifying the momentum flux. This makes it possible to precisely balance the hydrostatic pressure contributions associated with variations in valley geometry. The characteristic method is applied to the revised equations, yielding topographic corrections to the numerical fluxes of an upwind scheme. Further adaptations endow the scheme with an ability to capture transcritical sections and wetting fronts in channels of abrupt topography. To test the approach, the scheme is first applied to idealized benchmark problems. The method is then used to route a severe flood through a complex river system: the Tanshui in Northern Taiwan. Computational results compare favorably with gauge records. Discrepancies in water stage represent no more than a fraction of the magnitude of typical bathymetry variations.