级配砂石地基条件下核安全级廊道结构地震响应分析

级配砂石处理核安全级廊道结构的软弱地基有良好的发展前景,发展级配砂石地基条件下的廊道地震响应分析模型是评价其抗震安全性的关键问题。以某核电厂废液输送机排放廊道为研究对象,通过引入等价线性法描述近场级配砂石地基的非线性特征,在分析模型底部施加黏性边界模拟半无限空间,在截断边界的两侧施加黏性边界考虑波动的逸散效果,通过无厚度Goodman单元模拟廊道结构与周围地基的摩擦效应,并利用基于有限元法的自由场响应分析实现地震动输入,从而建立了级配砂石地基条件核安全级廊道结构地震响应分析计算模型。最后,通过开展级配砂石与回填素混凝土两种地基处理条件的廊道地震响应对比分析,该模型表现出良好的规律性及工程应用效果。研究成果可为在建项目、后续核电项目此类问题的地基处理提供借鉴与参考。     

Stable carbon and hydrogen isotopes of gases from the large tight gas fields in China

By the end of the year 2010,a total of 15 large tight gas fields have been found in China,located in the Ordos,Sichuan,and Tarim basins.The annual production and total reserves of these fields in 2010 were 222.5×108and 28657×108m3,respectively,accounting for 23.5%and 37.3%,respectively,of the total annual production and reserves of natural gases in China.They took a major part of all natural gas production and reserves in China.According to the analyses of 81 gas samples,the stable carbon and hydrogen isotopic compositions of tight gases in China have following characteristics:(1)Plots of 13C1-13C2-13C3,13C1-C1/C2+3and 13C1-13C2demonstrate the coal-derived origin of tight gases in China;(2)For the primary alkane gases,both carbon and hydrogen isotopic values increase with increasing molecular mass,i.e.,13C113C213C313C4and2H12H22H3;(3)The isotopic differences of 13C2-13C1,13C3-13C1,2H2-2H1and 2H3-2H1decrease with increasing Ro(%)and C1/C1–4;(4)There are seven causes for the carbon and hydrogen isotopic reversal,however,the carbon and hydrogen isotopic reversal of tight gases in China is caused mainly by multiple stages of gas charge and accumulation.     

航空能谱测量数据在砂岩型铀矿找矿预测中的应用

以澳大利亚弗罗姆湖地区砂岩型铀矿为例,利用航空能谱测量铀、钍、钾元素之间的地球化学特征差异,建立并计算古铀量、活性铀、地球化学活动性指数等特征参数,综合研究区盆地构造、古河道展布及地层岩性等特征,识别研究区的铀源区、铀元素迁入区、氧化-还原地球化学障等成矿预测要素,在ARCGIS 10平台上融合这些要素,最后圈定出研究区砂岩型铀矿找矿的有利远景区.研究表明航空能谱测量可以作为一种预测砂岩型铀矿有利远景区的有效方法.     

基于Kelvin-Voigt黏弹性骨架的含非饱和流体孔隙介质BISQ模型(英文)

本文综合考虑了在波传播过程中孔隙介质的三种重要力学机制——"Biot流动机制一squirt流动机制-固体骨架黏弹性机制",借鉴等效介质思想,将含水饱和度引入波动力学控制方程,并考虑了不同波频率下孔隙流体分布模式对其等效体积模量的影响,给出了能处理含粘滞性非饱和流体孔隙介质中波传播问题的黏弹性Biot/squirt(BISQ)模型。推导了时间-空间域的波动力学方程组,由一组平面谐波解假设,给出频率-波数域黏弹性BISQ模型的相速度和衰减系数表达式。基于数值算例分析了含水饱和度、渗透率与频率对纵波速度和衰减的影响,并结合致密砂岩和碳酸盐岩的实测数据,对非饱和情况下的储层纵波速度进行了外推,碳酸盐岩储层中纵波速度对含气饱和度的敏感性明显低于砂岩储层。     

同步提取三参数小波变换及其在储层含气性检测中的应用

随着我国石油勘探程度的不断加深,非常规油气藏逐步成为了油气勘探的重点.由于致密砂岩具有低孔、低渗、非均质性强等特性,因此迫切需要高精度时频分析后处理方法对该类气藏进行有效表征.本文提出了一种同步提取三参数小波变换（Synchroextracting Three-Parameter Wavelet Transform,SETPWT）新方法,该方法具有小波变换多尺度多分辨率的特性,通过改变三个参数来调节小波基的主频、带宽及相位,灵活匹配多种类型的合成信号以及地震子波;与传统时频分析方法相比,同步提取三参数小波变换在三参数小波变换结果的基础上引入同步提取算子（Synchronous Extraction Operator,SEO）,通过SEO提取与信号理想时频谱高度相关的时频信息,去除多余能量,从而实现非平稳信号的高精度时频表征.合成信号算例表明,同步提取三参数小波变换的分辨率不但明显高于常用时频变换,同时具有优于同步提取变换（Synchroextracting Transform,SET）的抗噪性能;将同步提取三参数小波变换应用到地震资料含气性检测中,进一步验证了该时频算法在致密砂岩含气性检测中的潜力.

     

Conditional Indicator Simulation: Application to a Saskatchewan uranium deposit

Mineral deposits frequently exhibit a mixture of rock types in which each type can be identified by a characteristic metal concentration. Such a mixture can be correctly simulated by first reproducing the spatial and geometric configuration of the various rock types in the deposit. Then the grades for each rock type can be jointly simulated and filled in according to their specific coregionalization characteristics. The method of Conditional Indicator Simulation and an uranium—arsenic joint simulation are presented with a detailed, step-by-step application to the Midwest deposit, a high grade uranium deposit in northern Saskatchewan.     

古新世特提斯喜马拉雅南亚带石英砂岩成因及其构造意义:以藏南岗巴地区古新统基堵拉组为例

特提斯喜马拉雅南亚带作为印度被动大陆北缘的主要构造单元,相较于其他类似构造单元发育着多套特殊的石英砂岩,意味着被动大陆边缘物源区陆源碎屑供应能力的多次变化,而引起印度被动大陆北缘石英砂岩沉积的构造背景和构造意义尚不明确。以特提斯喜马拉雅南亚带的岗巴地区古新统基堵拉组石英砂岩为例,通过砂岩碎屑成分分析、古流向恢复、重矿物分析和碎屑锆石年代学方法,对基堵拉组石英砂岩的沉积学及物源区特征,以及蕴含的成因和构造意义进行探讨。从沉积相分析结果来看,在早古新世岗巴地区所属的板块为印度被动大陆边缘,处于新特提斯洋的海岸线附近,以滨岸相为主,显示了一种浅海陆棚到陆相的变化。从砂岩岩相学的结果分析,基堵拉组的陆源碎屑物主要是成熟度极高的石英砂岩,同时古水流近NNE方向。从碎屑锆石年代学数据分析结果可知,基堵拉组的碎屑锆石年龄特征与早白垩世德干高原地区相吻合。故认为基堵拉组石英砂岩的形成是由于印度北缘的陆源碎屑供应量突然增多与被动大陆边缘物源区构造抬升导致,而引起被动大陆边缘物源区构造抬升的原因主要与德干大火成岩省形成相关。最终认为石英砂岩的发育成因与印度大陆北缘德干大火成岩省形成时构造隆升所导致的稳定克拉通再活化有关。     

Sedimentological–ichnological model for tide‐dominated shelf sandbodies: Lower Cambrian Gog Group of western Canada

Dunes and bars are common elements in tide‐dominated shelf settings. However, there is no consensus on a unifying terminology or a systematic classification for thick sets of cross‐stratified sandstones. In addition, their ichnological attributes have hardly been explored. To address these issues, the properties, architecture and ichnology of compound cross‐stratified sandstone bodies contained in the Lower Cambrian Gog Group of the southern Canadian Rocky Mountains are described here. In these transgressive sandstones, five types of compound cross‐stratified sandstone are distinguished based on foreset geometry, sedimentary structures and internal heterogeneity. These represent four broad categories of subtidal sandbodies: (i) compound‐dune fields; (ii) sand sheets; (iii) sand ridges; and (iv) isolated dune patches; tidal bars comprise a fifth category but are not present in the Gog Group. Compound‐dune fields are characterized by sigmoidal and planar cross‐stratified sandstone in coarsening‐upward and thickening‐upward packages (Type 1); these are mostly unburrowed, or locally contain representatives of the Skolithos ichnofacies, but are intercalated with intensely bioturbated sandstone containing the archetypal Cruziana ichnofacies. Sand‐sheet complexes, also composed of compound dunes, cover more extensive subtidal areas, and comprise three adjacent subenvironments: core, front and margin. The core is characterized by thick‐bedded sets of cross‐stratified sandstone (Type 2). A decrease of bedform size at the front is recorded by wedges of thinner‐bedded, low‐angle and planar cross‐stratified sandstone (Type 3) exhibiting dense Skolithos pipe‐rock ichnofabric. The margin is characterized by interbedded sandstone and mudstone, and hummocky cross‐stratified sandstone. Sand‐sheet deposits exhibit clear trends in trace‐fossil distribution along the sediment transport path, from non‐bioturbated beds in the core to Skolithos ichnofacies at the front, and a depauperate Cruziana ichnofacies at the margin. Tidal sand ridges are large elongate sandbodies characterized by large sigmoid‐shaped reactivation surfaces (Type 4). Sand ridges display clear ichnological trends perpendicular to the axis of the ridge, with no bioturbation or a poorly developed Skolithos ichnofacies in the core, a depauperate Cruziana ichnofacies in lee‐side deposits, and Cruziana ichnofacies at the margin. While both tidal ridges and tidal bars migrate by means of lateral accretion, the latter occur in association with channels while the former do not. Because tidal bars tend to occur in brackish‐water marginal‐marine settings, their ichnofauna are typically of low diversity, representing a depauperate Cruziana ichnofacies. Isolated dune patches developed on sand‐starved areas of the shelf, and are represented by lenticular sandbodies with sigmoidal reactivation surfaces (Type 5); they typically lack trace fossils, but the interfingering muddy deposits are intensely bioturbated by a high‐diversity fauna recording the Cruziana ichnofacies. The variety of sandbody types in the Gog Group reflects varying sediment supply and location on the inner continental shelf. These, in turn, governed substrate mobility, grain size, turbidity, water‐column productivity and sediment organic matter which controlled trace fossil distribution.     

二连盆地砂岩型铀矿土壤氡异常模型及应用

二连盆地是我国北方重要的砂岩型铀矿产地之一。为提取地表弱矿化信息,建立直接找矿标志,在盆地内实施面积型土壤氡及其子体测量,通过剖面、平面叠合铀矿化信息分析,建立了砂岩型铀矿土壤氡异常模型:即土壤氡气异常往往位于铀矿体上游一侧,异常值高达15000 Bq/m3以上,矿体上方大多为氡气背景值,而矿体下游一侧多为氡的偏高晕。此模型揭示二连盆地具有较好的铀成矿潜力,指明了进一步铀矿找矿方向。     

新疆阿吾拉勒山地区晚石炭世地层化石的新资料

新疆阿吾拉勒山地区晚石炭世地层分布于阿布热勒山西端。介绍了新疆阿吾拉勒山地区巴喀勒萨依上石炭统伊什基里克组地层剖面、生物化石、含铜砂岩分布特征及乌鲁克得萨依科古琴山组生物化石资料,并讨论了其时代归属。