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21.
Oil/Gas Accumulation Characteristics and Exploration Methods of the Deltaic Lithologic Reservoirs in Northern Shaanxi Area 总被引:2,自引:0,他引:2
鄂尔多斯盆地陕北地区中生界三叠系延长组发育大型三角洲体系,形成了两套有利的生储盖组合,并发育多套油层。勘探实践证明:油藏的形成和分布受延长组生油凹陷的控制,三角洲储集砂体是形成大型油田的物质基础,次生浊沸石溶解在低渗透背景上形成相对高渗区,储油砂体上倾岩性变化构成隐蔽性岩性圈闭遮挡条件,形成的三角洲油藏具有规模大、工业产层多、油气资源丰富的特点。通过对鄂尔多斯盆地陕北地区石油成藏地质条件进行分析,总结出岩性油藏的成藏特征及勘探方法,深化和丰富了岩性油藏勘探理论,推动了陕北地区三角洲油藏的勘探步伐。 相似文献
22.
由于目前海洋天然气水合物(以下简称水合物)钻采案例少、取样成本高、保温保压技术难度大,导致对其储层物性原位测试及资源等级定量分类评价认识不清、资源等级划分与开发模式响应关系不明。为此,根据南海北部实际水合物取样岩心资料,利用室内水合物声电力学测试装置,测定了不同组分、饱和度下含水合物沉积物的声波、电阻率、饱和度、渗透率、偏应力以及应变等物性参数,基于层次分析法,建立了水合物物性参数敏感度熵权综合评价模型,对水合物参数敏感性进行了评价;进而依据参数变化规律和敏感性分析结果,建立了海域水合物的物理参数评价方法与划分标准。研究结果表明:①南海北部水合物储层主要为胶结强度较差的砂泥质粉砂为主,粉砂、黏土含量较高,储层中位粒径主要介于9~30 μm,水合物饱和度范围介于20%~60%,解析气主要为甲烷气体;②水合物参数敏感性从高到低顺序依次为:偏应力、应变、气量、纵波速度、电阻率、渗透率和横波速度;③南海北部水合物藏综合划分为非成岩Ⅰ类、非成岩Ⅱ类、非成岩Ⅲ类和成岩Ⅳ类、成岩Ⅴ类;④南海北部荔湾区域水合物储层属于泥质浅层沉积,无完整圈闭构造,结构较为松散,属于非成岩Ⅱ类水合物藏,水合物钻采面临工程风险、地质风险、设备风险3大安全风险。结论认为,该研究成果为后续海域水合物资源评价、分类以及与之对应的合理开发方式优选提供了理论指导和技术方法。 相似文献
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为从水利基础设施建设方面对支撑皖北地区加快发展提出政策建议,以地区发展实际结合防洪减灾、供水保障等需求综合分析的方法,介绍了皖北地区经济社会和水利基础设施概况,从水旱灾害防御、水资源保障、水生态环境、水利信息化等方面分析了皖北地区水利基础设施存在的问题与不足,提出了畅通骨干防洪通道,增强洪水调蓄能力,提升城市防洪排涝能力,提高重点涝区排涝能力,建设重大引调水工程和区域水资源配置工程,保障乡村振兴用水需求,实施水生态环境和地下水超采治理,保障河湖生态环境需水,完善水网信息基础设施,构建数字孪生流域等工程措施建议,为皖北地区高质量发展提供坚实的水安全保障。 相似文献
25.
作为城市防御和管理而形成的里坊制度,其解体是一个综合因素作用的过程,以往的研究偏重于商品经济的影响。从北宋东京城市防御体系的角度出发,主要探讨战争、城市管理、城市治安等军事因素与里坊制解体的关系,指出厢坊制管理模式的出现是里坊制解体的首要标志。 相似文献
26.
从晋北民居的地域性、建筑材料使用、节能保温措施、采光通风等几个方面介绍了山西晋北民居中的建筑节能理念,从而为地区特色的可持续发展的建筑提供新的建筑节能思想。 相似文献
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28.
A shadow fraction method for mapping biomass of northern boreal black spruce forests using QuickBird imagery 总被引:1,自引:0,他引:1
A. Leboeuf A. Beaudoin R.A. Fournier L. Guindon J.E. Luther M.-C. Lambert 《Remote sensing of environment》2007,110(4):488-500
We have developed and tested a method for mapping above-ground forest biomass of black spruce (Picea mariana (Mill.) B.S.P.) stands in northern boreal forests of eastern Canada. The method uses QuickBird images and applies image processing algorithms to extract tree shadow fraction (SF) as a predictive variable for estimating biomass. Three QuickBird images acquired over three test sites and 108 ground sample plots (GSP) were used to develop and test the method. SF was calculated from the fraction of tree shadow area over the area of a reference square overlaid on the images. Linear regressions between biomass of GSP and SF from the images for each test site resulted in R2 in the range from 0.85 to 0.87 (except one case at 0.41), RMSE of 11 to 18 t/ha and bias of 2 to 5 t/ha. Statistical tests demonstrated that local regressions for the three test sites were not statistically significantly different. Consequently, a global regression was calculated with all GSP and produced R2, RMSE, and bias of 0.84, 14.2 t/ha and 4.2 t/ha, respectively. While generalization of these results to extended areas of the boreal forest would require further assessment, the SF method provided an efficient means for mapping biomass of black spruce stands for three test areas that are characteristic of the northern boreal forest of eastern Canada (boreal and taiga shield ecozones). 相似文献
29.
Frederick D. Parker 《Cryptologia》2013,37(4):295-313
In 1941, the United States Navy intercepted enough Japanese naval messages to predict the attack on Pearl Harbor if the code which protected them had been solved. The messages would have disclosed that, while the Japanese government cynically conducted diplomatic negotiations with the United States, the Japanese Combined Fleet under Admiral Isoroku Yamamoto, beginning as early as September 1941, systematically prepared ships, crews, weapons, tactics, and a complicated fuel supply system for the most ambitious operation ever undertaken by the Japanese navy. Details of Japan's intentions were hidden from Navy cryptanalysts because of limited manpower resources and because all Japanese navy codes were assigned a lower priority than Japanese diplomatic codes and German submarine threat. 相似文献
30.
In order to investigate vehicle fuel quality in northern China, the sulfur content of fuels purchased from the market has been studied. 235 samples from urban areas and highway service stations were collected and tested with energy dispersive X-ray fluorescence spectrometry. 88% of the gasoline samples contained sulfur below 500 ppm, the limit then in effect, and 92.5% of the diesel fuel samples were below 2000 ppm, the required limit. China's Ministry of Environmental Protection recommend lower sulfur to assure that the vehicles using the fuels comply with the China III emission standards—those limits are 150 ppm sulfur for gasoline and 350 ppm for diesel fuel. The recommended limits were not often met: in Jinan, Shanghai, Changchun and Xi'an, 0%, 11%, 46% and 60% of the gasoline sampled were below 150 ppm sulfur. For samples from highway stations, only 14–58% of gasoline was under the 150 ppm sulfur and only 0–67% of diesel samples below 350 ppm in different regions. This mismatch, between fuel sulfur levels that would enable vehicle emission controls to operate effectively, and the actual fuel sulfur levels at service stations, results in unnecessarily high pollution from potentially cleaner vehicles. 相似文献