Geologic Characteristics of Gas Reservoirs in West Sichuan Foreland Basin     

YANG Keming 《《地质学报》英文版》2008,82(6)

The foreland basin in West Sichuan is a tectonic unit that has undergone multi-periods tectonic movements of Indosinian-Yanshanian-Himalayan. Since late Triassic, it has been in a passive subsidence environment controlled by basin margin mountain systems and by the compression with abundant sediment sources. With the complex geologic setting, the main geologic characteristics of natural gas reservoir are listed as following:(1)Source rocks are coal-bearing mud and shale series with high to over maturity, and long and progressive hydrocarbon generation-displacement period. The key accumulation period is middle-late Yanshanian epoch.(2)There are three gas-bearing systems vertically, each of which has different reservoir mechanism, main-controlled factors and distribution law, so the exploration thoughts and techniques are also different.(3)Undergoing multi-period generation-migration-accumulation, oil and gas have encountered multi-period modification or destruction, and gas accumulation overpass multiple tectonic periods. So the trap type is complicated and dominated by combination traps. Because the main accumulation period of natural gas is early and the reservoir encountered the modification of strong Himalayan movement, there is great difference in the fullness degree of gas reservoirs and complicated gas-water relation. (4) Reservoir is tight to very tight, but reservoirs of relatively high quality developed under the super tight setting. (5) The key techniques for oil and gas exploration in west Sichuan foreland basin are the prediction of relatively favorable reservoirs, fractures and gas bearing; and the key techniques for oil and gas development are how to improve the penetration rate, reservoir protection and modification.  相似文献   

Mesoproterozoic Continental Arc Type Granite in the Central Tianshan Mountains: Zircon SHRIMP U-Pb Dating and Geochemical Analyses     

YANG Tiannan  LI Jinyi  SUN Guihu  WANG Yanbin 《《地质学报》英文版》2008,82(1):117-125

The Central Tianshan belt in northwestern China is a small Precambrian block located in the southern part of the Central Asia Orogenic Belt （CAOB）, which is considered as ＂the most voluminous block of young continental crust in the world＂ that comprises numerous small continental blocks separated by Paleozoic magmatic arcs. The Precambrian basement of the central Tianshan Mountains is composed of volcanic rocks and associated volcano-sedimentary rocks that were intruded by granitic plutons. Geochemical analyses demonstrate that the granitic plutons and volcanic rocks were generated in the Andean-type active continental arc environment like today＇s Chile, and the zircon U-Pb SHRIMP dating indicates that they were developed at about 956 Ma, possibly corresponding to the subduction of the inferred Mozambique Ocean under the Baltic-African super-continent.  相似文献   

Multifractal Analysis of Element Distribution in Skarn-type Deposits in the Shizishan Orefield, Tongling Area, Anhui Province, China   总被引：3，自引：1，他引：2  

Wang Qingfei  Deng Jun  Wan Li  Zhao Jie  Gong Qingjie  Yang Liqiang  Zhou Lei  Zhang Zhijun 《《地质学报》英文版》2008,82(4):896-905

A series of element concentrations sampled from four drill cores with a length about 1000 m into different skarn-type deposits were selected from the Shizishan orefield, central Tongling, southeastern part of Anhui Province. Using the multifractal method, the distribution and migration characteristics of the major and trace elements are analyzed. The multifractal spectrum of the major elements is left-skewed, whereas the spectrum of the trace elements is right-skewed, which shows that in the process of skarn formation, the trace elements were enriched only locally, and major elements transported within a much larger range. The correlation coefficients of the multifractal parameters Aa （width of the multifractal spectrum） of the four drill cores are relatively low, but the correlation coefficients of the multifractal parameters R （spectrum symmetry parameter） and Af are relatively higher, indicating that although the non-homogeneous intensity of the distribution of elements is inconsistent, their spatial accumulation patterns are almost the same during the ore-forming process. The statistics of the mnltifractal parameters of various elements in the different locations show that the ore-forming processes and element migration pattern in the Shizishan orefield are consistent, and that the migrations of trace elements and major elements exhibit some differences.  相似文献   

Late Cenozoic Stratigraphy and Paleomagnetic Chronology of the Zanda Basin, Tibet, and Records of the Uplift of the Qinghai-Tibet Plateau   总被引：1，自引：0，他引：1  

MENG Xiangang  ZHU Dagang  SHAO Zhaogang  YANG Chaobin  HAN Jianen  YU Ji  MENG Qingwei  LU Rongping 《《地质学报》英文版》2008,82(1):63-72

The characteristics of Late Cenozoic tectonic uplift of the southern margin of the Qinghai- Tibet Plateau may be inferred from fluvio-lacustrine strata in the Zanda basin, Ngari, Tibet. Magnetostratigraphic study shows that the very thick fluvio-lacustrine strata in the basin are 5.89- 0.78 Ma old and that their deposition persisted for 5.11 Ma, i.e. starting at the end of the Miocene and ending at the end of the early Pleistocene, with the Quaternary glacial stage starting in the area no later than 1.58 Ma. Analysis of the sedimentary environment indicates that the Zanda basin on the southern Qinghai-Tibet Plateau began uplift at -5.89 Ma, later than the northern Qinghai-Tibet Plateau. Presence of gravel beds in the Guge and Qangze Formations reflects that strong uplift took place at -5.15 and -2.71 Ma, with the uplift peaking at -2.71 Ma.  相似文献   

湘西沃溪钨锑金矿床成矿的独特性   总被引：2，自引：0，他引：2       下载免费PDF全文

陈明辉  杨洪超  娄亚利  包正相  鲍珏敏 《地质找矿论丛》2008,23(1):32-35,42

沃溪钨锑金矿床位于NE向雪峰弧形构造带向北西凸出的转折部位东段,赋存于新元古界板溪群马底驿组紫红色板岩中,产在沃溪近EW向低角度拆离断层下盘沿层发育的层间剪切断裂系统,以层间石英脉型矿体为主,矿化作用在时间上和空间上具有一定的分带性和规律性.矿体沿倾向延深大于走向延长数倍至10余倍,并普遍存在侧伏延伸的规律.杂多酸络合物作为W,Sb,Au成矿组合的共同载体,使它们共同进入热液地球化学迁移,并生成钨锑金共生组合的金矿床,成为重要的成矿地球化学机制.  相似文献   

矿井涌水量混沌时间序列分析与预测   总被引：5，自引：0，他引：5  

陈玉华  杨永国  彭高辉 《煤田地质与勘探》2008,36(4)

矿井地下水系统是个非线性系统,由于地下水系统的复杂性,很难完全确定影响矿井涌水量的因素,因此传统的矿井涌水预测表现出较大的局限性。而混沌时间序列分析能够利用单变量处理方法,分析矿井地下水系统中,由于多因素耦合作用所产生的矿井涌水量时间序列。通过对某矿区1985年9月至2005年2月矿井涌水量时间序列资料的分析,显示矿井涌水量时间序列具有混沌特征;通过对比预测值和实测值,表明预测精度高。因此,混沌时间序列分析方法用于矿井涌水量预测是可行的。  相似文献   

RBF网络在地质样品非线性基体效应校正中的应用     

闫玉生  杨雪梅  穆克亮 《物探化探计算技术》2008,30(2):169-172

基于RBF(Radial Basis Function)网络的正交最小平方算法,对攀枝花地质样品进行动态非线性基体效应校正.首先采用EDXRF仪器对样品进行测量,并对样品的荧光计数进行归一化,设计出自动分类模型和动态非线性数据基体效应校正模型的二级串联结构,用自组织神经网络(SOFM)进行分类,然后用RBF网络预测了未知样品元素Ti的百分含量.结果表明:对所预测样本的Ti的百分含量与化学分析相比的误差均小于0.5%.由此可见,用RBF方法可以有效地对地质样品进行非线性基体效应校正,能够达到工矿生产的要求.  相似文献   

天山公路地质灾害决策支持地理信息系统的设计研究   总被引：1，自引：0，他引：1  

尹江涛  何政伟  杨斌  张东辉  张俊峰  张峰  袁明 《物探化探计算技术》2008,30(6)

天山公路由于其特殊复杂地形、地质条件及受降雨、地下水等因素,严重影响其正常通行,同时天山公路还经常受到泥石流、滑坡、崩塌、溜砂坡等地质灾害的危害,这对该公路稳定性和沿线居民的安全性都具有一定的威胁。因此,运用先进的技术手段,建立一套适应于天山公路的地质灾害决策支持信息系统就显得尤其重要。该系统的建立,对天山公路的建设改造和管理提供了强有力的支持。天山公路地质灾害决策支持地理信息系统利用强大的ArcEngine开发组件,针对新疆天山公路实际,引入RS、GIS的相关理论、方法和技术分析手段,采用相应的数学分析评价模型,对提高天山公路地质灾害防治管理水平和地质灾害的有效防治,以及评价决策等方面,都具有重要的意义。  相似文献   

沿空掘巷合理煤柱宽度综合分析与确定   总被引：3，自引：0，他引：3  

奚家米  毛久海  杨更社  王进锋 《煤田地质与勘探》2008,36(4)

在总结分析经验法、理论计算法、数值模拟法、现场实测等确定煤柱宽度方法优缺点的基础上,提出了采用现场实测和数值模拟相结合的方法来确定保留煤柱宽度。根据石炭井二矿生产实际,分别对巷道开挖前后,不同煤柱宽度下围岩应力、变形进行了模拟,同时利用21053工作面异型煤柱的有利条件,对不同煤柱宽度下巷道围岩变形、支护结构受力等进行了实测。经过对监测数据的分析,得出了巷道围岩变形、支护结构受力与煤柱宽度之间的关系,结合数值模拟结果,确定了石炭井二矿煤柱宽度。  相似文献   

遥感蚀变信息检测中背景与干扰问题研究   总被引：3，自引：0，他引：3  

张远飞  吴德文  朱谷昌  杨自安 《国土资源遥感》2008,(2):22-27

在不同自然景观区的遥感蚀变信息检测中,背景与干扰是2个复杂而又容易混淆的研究对象。本文结合光谱混合模型理论与随机变量概率分布相关理论,深入分析了遥感数据的光谱空间几何结构特征(重点剖析二维散点图),系统研究了背景与干扰的关系、复杂度以及干扰地物类型的划分等问题。这些问题的探讨为遥感蚀变信息检测的最佳方案设计和蚀变信息潜在性评价与准确提取提供了技术思路。  相似文献