低渗低阻产水气藏气水层识别:以广安气田须家河组为例

广安气田上三叠统须四段和须六段气藏发育了构造气藏、构造-岩性气藏和岩性气藏.储层具有低孔、低渗、低阻和高束缚水饱和度特征.空间上,储层孔渗相关关系变化大,气水分布复杂,气水层识别困难.根据岩心对测井的标定,研究了须四段和须六段四性关系,认识到储层为细砂岩、中砂岩和粗砂岩,具有低自然伽马、低补偿密度、低电阻率和高声波时差特征,而物性与含气性无明显相关性.采取了分层、分区块建立储层孔隙度、渗透率模型,提高了物性解释精度.不同气藏类型具有不同的气水分布,应用阵列感应、核磁共振和综合判识3种方法进行了气水层识别,提高了广安气田气水层识别精度.这些方法在广安气田的应用表明可以准确识别构造气藏和构造-岩性气藏的气、水层,但对构造幅度低的岩性气藏识别精度不高,因为在这些岩性气藏中气水分异不彻底,气层与气水同层、水层含水饱和度是渐变的.      

我国典型海洋型冰川区高海拔区输出水量变化对气候变暖的响应

通过丽江盆地气象水文观测资料研究发现: 冰雪消融加剧、融水增加, 漾弓江流域径流量明显上升; 高海拔冰雪区消融期提前, 春季径流增加明显; 高海拔冰雪区的径流输出对漾弓江流域水量平衡的贡献量逐年增加, 体现了全球气候变暖背景下高海拔冰雪区对整个流域水循环的重要性.对海螺沟流域实测气象水文资料的分析也表明, 气候变暖背景下, 该流域冰雪区水量输出也逐年上升.两流域高海拔区输出水量的剧烈增加, 明显响应了气候变暖, 表明了流域水循环的加速, 这必然将对区域的发展和资源开发产生重要影响.      

SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau

Metabasites consisting of metamorphic ultra-mafic rocks, cumulate gabbro, gabbro (diabase), basalt, and plagiogranite are exposed at the Taoxinghu area in central Qiangtang, northern Tibetan Plateau. Zircon SHRIMP U-Pb dating for the cumulate gabbro yields a weighted mean age of 467±4 Ma, which is the oldest and most reliable magmatic age in this area. Zircon 176Hf/177Hf ratios range from 0.282615 to 0.282657, with εHf(t) values of 5.02±0.28, indicating that the cumulate gabbro was mainly derived from the depleted mantle. In addition, geochemical data of metabasites suggest that they have similar characteristics to those in the mid-ocean ridge basalts (MORB). The Taoxinghu metabasites may represent the fragment of Early Paleozoic ophiolite in the "Central Uplift" of the Qiangtang, northern Tibetan Plateau.     

地上下一体化的三维空间数据库模型设计与应用

大规模地上、地下三维实体建模与空间分析应用中,由于三维模型的多样性和对象空间分布的不均衡性,如何高效地一体化组织和管理海量三维空间数据成为当前三维GIS的核心问题之一.提出了一种兼顾空间关系与语义关系的三维空间数据库模型,给出了相应的概念模型、逻辑模型和物理模型.特别针对地质体的复杂性,给出了顾及语义的多尺度地下空间目标概念模型和多层次三维空间索引机制.用武汉市和南京市三维数字城市示范区模型数据进行了应用试验分析,验证了该模型的有效性.      

MML-EM方法及其在化探数据混合分布中的应用

概率图法在筛分混合分布的问题上,只能对混合分布的各项参数作出粗略的估计.为了解决这一问题,引入了MML-EM法.模拟研究表明,在混合分布参数估计上,该方法比概率图法有更高的精度.以江西大吉山钨矿石英脉原生晕数据为例,经过该方法的筛分,得到钨、钽和铌的含量服从由2个子分布组成的混合对数正态分布,即双峰分布.结合前人的地质研究,可以初步得出结论:钨的高值总体代表了岩浆期后热液成矿期的热液充填石英脉型矿化,低值总体可能代表其他成矿期的事件,其中高值部分可能构成岩浆晚期浸染型的弱钨矿化.钽和铌的高值总体代表岩浆晚期的浸染型富矿化,低值总体代表其他成矿期的叠加矿化.该方法为化探数据中混合分布的筛分以及解释多地质成因总体提供了一种良好的定量化工具.      

Characteristics of Coal Accumulation of Transform-Extensional Basins in Linear Fracture Zones: A Case Study of the Meihekou Basin

This paper discusses the characteristics of coal accumulation of transfor-extensional basins in linearfracture zones on the basis of an analysis of tectonic evolution and sequence stratigraphy in the Meihekou basin.Coal accumulation of the basin occurred mainly in the accelerated rifting period of the transtentional regime and inthe late period of tectonic transformation of the transpressional regime. In the former period, swamps developed inshallow lakes. The thickness of coal seams was controlled by the activity of fault block. Thick coal was formed in adownfaulted trough. In the latter period, swamps developed in a braided fan delta plain. The coal seams are thin andhave poor lateral continuity. The thickness of coal seams was controlled by the migration of water channels in thebraided plain.     

Isotopic Geochronology of the Xianghongdian Alkaline Complex, Northern Margin of the Dabie Mountains, China

To the north of the Qinling-Dabie orogen there exists a Mesozoic (K1) granite-syenite belt called the Beihuaiyang granite-syenite belt, in which the Xianghongdian alkaline complex outcrops in the Devonian Foziling schist and also intruded into the slightly earlier volcanic rocks. This alkaline complex is composed of syenite, alkaline syenite and nepheline syenite, but the nepheline syenite occurs inside the alkaline syenite in the pod-like, irregular, lenticular or layered shape. Researches on the petrogenesis of the alkaline complex and the relationship between the alkaline syenite and the nepheline syenite must rely on precise isotopic ages. Previous researches have reported iso-topic dating results merely by the 40Ar/39Ar method on hornblende and biotite separated from the alkaline syenite and nepheline syenite. In view of this, the authors have made fairly detailed isotopic geochronological studies of the alkaline syenite and nepheline syenite by using Rb-Sr isochron for the whole rock and minerals,     

Sources of Cretaceous Bimodal Volcanic Rocks in the Coastal Region of Southeastern China -- Constrains of the Sr content and its isotopes

Cretaceous volcanism in the coastal region of southeastern China was characteristized by occurrenceof bimodal volcanics consisting of basalts and rhyolites, the geneses of which are still controversial. Based on the factthat their isotopic compositions are similar but the Sr content of the former is much higher than that of the latter, thispaper discusses the respective sources of the two end-member rocks, and concludes that basalts were derived fromthe subduction-related enriched upper mantle wedge and their isotopic compositions had not been affected by crustalassimilation, whereas rhyolites were formed by remelting of the old metamorphic basement, but they were mixed upwith the underplating basaltic magmas to various degrees so that their Sr isotopic compositions varied significantlyfrom the sources and tended to be homogeneous to the latter.     

海泡石活性土对食用菜油的脱色作用

海泡石粘以活化后,对食用菜油精制脱色效果良好,其活化工艺条件为：活化酸量８％,烘干温度１５０℃,活化温度１００℃,活化时间〉５ｈ液固比３：１。     

深层搅拌法在湘北地区的应用前景

本文扼要介绍了深层搅拌法的工艺技术及适用范围,对湘北地区的工程环境条件进行了分析讨论,认为在湘北地区推广这一施工技术不仅具备工程地质条件,而且有关十分广阔的应用前景。