Effect of Shale Reservoir Characteristics on Shale Oil Movability in the Lower Third Member of the Shahejie Formation,Zhanhua Sag     

NING Chuanxiang  MA Zhongliang  JIANG Zhenxue  SU Siyuan  LI Tingwei  ZHENG Lunju  WANG Guozhen  LI Fengxun 《《地质学报》英文版》2020,94(2):352-363

To reveal the effect of shale reservoir characteristics on the movability of shale oil and its action mechanism in the lower third member of the Shahejie Formation(Es3l), samples with different features were selected and analyzed using N2 adsorption, high-pressure mercury injection capillary pressure(MICP), nuclear magnetic resonance(NMR), high-speed centrifugation, and displacement image techniques. The results show that shale pore structure characteristics control shale oil movability directly. Movable oil saturation has a positive relationship with pore volume for radius > 2 μm, as larger pores often have higher movable oil saturation, indicating that movable oil is present in relatively larger pores. The main reasons for this are as follows. The relatively smaller pores often have oil-wetting properties because of organic matter, which has an unfavorable effect on the flow of oil, while the relatively larger pores are often wetted by water, which is helpful to shale oil movability. The rich surface provided by the relatively smaller pores is beneficial to the adsorption of immovable oil. Meanwhile, the relatively larger pores create significant pore volume for movable oil. Moreover, the larger pores often have good pore connectivity. Pores and fractures are interconnected to form a complex fracture network, which provides a good permeability channel for shale oil flow. The smaller pores are mostly distributed separately;thus, they are not conducive to the flow of shale oil. The mineral composition and fabric macroscopically affect the movability of shale oil. Calcite plays an active role in shale oil movability by increasing the brittleness of shale and is more likely to form micro-cracks under the same stress background. Clay does not utilize shale oil flow because of its large specific surface area and its block effect. The bedding structure increases the large-scale storage space and improves the connectivity of pores at different scales, which is conducive to the movability of shale oil.  相似文献   

基于金矿规格单元数据的机器学习方法在成矿建模分析中的应用     

张野  李明超  韩帅  任秋兵  朱月琴 《大地构造与成矿学》2020,(2):183-191

现代金矿勘察主要是通过综合地球化学和地质测量等数字化方法对深部矿床进行研究,所需要的人力物力成本较高。而通过分析积累的金矿规格单元数据,可以建立金矿成矿情况与相关成矿元素含量之间的非线性关系,从已有的勘查数据中寻找金矿成矿的一般规律。本文基于与金矿相关的成矿元素含量数据,分别采用逻辑斯蒂回归、随机森林和决策树方法对原始数据和重采样数据进行训练,综合运用召回率、精确率和准确率对模型进行评价。通过对比发现,在训练和测试原始数据过程中,由于每组之间数据量的巨大差距,导致成矿数据被淹没;而在训练重采样数据过程中,随机森林在召回率和准确率方面均有较好的表现,分别达到了90.63%和70.78%;并最终分析了随机森林模型中不同分类边界对于金矿成矿情况预测结果的影响。利用不同的测量指标对模型进行评价分析,使模型更适用于金矿成矿预测,可有效地提高金矿勘察的效率。  相似文献   

内蒙古沙麦钨矿区高分异花岗岩独居石U-Pb定年及成矿意义     

宓奎峰  杨艳  颜廷杰  吕志成  柳振江 《现代地质》2020,34(3):504-513

兴蒙造山带是中国北方重要的多金属成矿带,产出有一系列的钨多金属矿床。沙麦钨矿位于内蒙古二连浩特—东乌旗成矿带东侧,是兴蒙造山带发育的典型石英脉型钨矿床之一。通过对沙麦矿区出露的花岗岩开展独居石U-Pb测年,总结区域钨矿化的成矿年龄与矿化特征,探讨区域钨矿成矿时序及构造动力学背景。测年结果显示,沙麦矿区中细粒黑云母二长花岗岩、似斑状黑云母二长花岗岩LA-ICP-MS独居石U-Pb谐和年龄分别为(141.6±1.1) Ma 和(141.4±0.3) Ma,进一步确认沙麦钨矿形成于早白垩世。而二连浩特—东乌旗成矿带及其邻区钨矿化存在晚石炭世—早二叠世、早白垩世两期,成矿时代分别发生于约300 Ma和140~130 Ma。300 Ma成矿期钨成矿作用受古亚洲洋的影响;140~130 Ma成矿期为区域钨矿成矿作用高峰期,成矿作用受到古太平洋和蒙古—鄂霍次克洋构造体系叠加作用的影响。  相似文献   

甘肃北山老金厂金矿床载金矿物特征、原位硫同位素组成及其对成矿的指示意义     

黄式庭  于晓飞  吕志成  刘家军  李永胜  杜泽忠  吕鑫  孙海瑞  杜轶伦 《吉林大学学报(地球科学版)》2020,50(5):1387-1403

老金厂金矿床是北山成矿南带最具代表性的中低温岩浆热液型金矿床之一,其规模为中型。依据脉体穿插、矿物共生组合和矿石结构构造等特征,将矿床矿化作用过程划分为石英-黄铁矿阶段（Ⅰ）、石英-含砷黄铁矿-毒砂阶段（Ⅱ）、石英-黄铁矿-多金属硫化物阶段（Ⅲ）和石英-方解石阶段（Ⅳ）。利用电子探针研究了不同成矿阶段载金矿物的元素组成及其分布规律。Ⅰ阶段：黄铁矿以粗粒自形立方体为主,粒度为0.50~1.50 mm,贫As、Au;毒砂含量极少,呈细粒他形。Ⅱ阶段：含砷黄铁矿周围常有大量毒砂产出,含砷黄铁矿多为立方体、五角十二面体,粒度为0.30~1.00 mm,富As、Au;该阶段矿化最为强烈,毒砂主要形成于此时期,多呈棱柱状、柱状、放射状集合体,显示富S亏As特征。Ⅲ阶段：多以黄铁矿-黄铜矿-闪锌矿共生组合脉的形式产出,黄铁矿多呈长条状,以富S、Cu、Zn、Au和贫Fe、As为特征。Ⅳ阶段：矿化作用极弱,毒砂、黄铁矿含量极少,为细粒他形。原位硫同位素组成显示：Ⅰ阶段黄铁矿δ³⁴S_V-CDT值为-3.8‰~-2.9‰,均值为-3.3‰;Ⅱ阶段黄铁矿和毒砂δ³⁴S_V-CDT值为-4.7‰~2.6‰,均值为-3.3‰;Ⅲ阶段黄铁矿和闪锌矿δ³⁴S_V-CDT值主要分布于-1.9‰~1.0‰之间,均值为0.1‰。此3个阶段硫同位素组成反映了成矿期硫主要来源于幔源岩浆,混入了部分地层硫。综合前人研究成果,认为成矿早期至晚期,成矿流体总体上由富S贫As向富As贫S演化。Ⅰ阶段体系处于中性稳定的环境,硫源充足;Ⅱ阶段为贫S富As的高氧逸度环境,由于大气降水对地层的淋滤渗透,混入富As流体,Au可能与As结合形成Au-As络合物,在成矿有利部位富集沉淀;Ⅲ阶段成矿元素种类丰富,体系为富S贫As的弱还原环境,Au很可能与HS^-、S^-形成络合物进入黄铁矿晶格。  相似文献   

甘肃柳园地区早二叠世正长花岗斑岩脉锆石U-Pb年代学、岩石地球化学特征——对北山造山带晚古生代构造背景的指示     

孙海瑞  吕志成  于晓飞  李永胜  杜泽忠  吕鑫  公凡影 《吉林大学学报(地球科学版)》2020,50(5):1433-1449

甘肃北山地区位于中亚造山带中段,是诠释中亚造山带构造演化的关键区域之一,长期以来受到地质学界的广泛关注。柳园地区位于甘肃北山南带,区内脉岩发育,这些岩脉的研究可以为阐释北山造山带晚古生代构造背景提供更多证据。基于此,本文选取位于甘肃柳园地区的正长花岗斑岩脉开展了系统的锆石U-Pb-Hf同位素和全岩主量、微量元素分析。LA-ICP-MS锆石U-Pb分析显示,岩脉侵位于早二叠世（（288.5±1.4）Ma）。全岩地球化学分析显示,正长花岗斑岩脉的SiO₂和全碱质量分数较高,Fe、Mg、Ca、Al和P质量分数较低,Rb、Th、U和Pb相对富集,Ba、Nb、La、Ce、Sr和Ti等元素相对亏损,Eu负异常显著,具有较高的Rb/Sr值和较低的K/Rb值及锆石饱和温度（730~844℃,集中于740℃左右）,显示该岩脉为高钾钙碱性高分异I型花岗岩,并具有俯冲带岩浆活动的地球化学特征。正长花岗斑岩脉具有较低的Zr/Hf值（18.42~28.01,平均值为22.37）和Th/U值（3.82~7.99,平均值为5.34）,与平均地壳组分接近,锆石ε_Hf（t）值为2.94~9.66,平均值为5.72,T_DM2值为955~611 Ma,指示源区主体为新元古代地壳的部分熔融,并存在幔源物质加入。根据构造判别图解并结合前人关于二叠纪区域构造变形、盆地沉积物源、岩浆演化等方面的研究结果,笔者认为该正长花岗斑岩脉形成于俯冲作用过程中的局部伸展环境,并认为北山地区增生造山事件至少持续到早二叠世。  相似文献   

河北省崇礼幅1∶50 000矿产地质图数据库          下载免费PDF全文

甄世民  庞振山  薛建玲  程志中  白海军  左群超  缪建普  贾儒雅  姚磊  陈辉  张志辉  陶文 《中国地质》2020,47(S2):57-69

根据《固体矿产地质调查技术要求(1∶50 000)》(DD 2019-02)和行业其他规范要求,完成河北省崇礼幅1∶50 000专项地质填图379.93 km²、矿点检查11处,采集水系沉积物样品1622件、重力测量物理点1623个,测试锆石U-Pb年龄样3组、流体包裹体样80余件,系统编制了河北省崇礼幅1∶50 000矿产地质图,并建立了数据库。突出了对燕山期岩浆岩和相关脉岩、碱性杂岩体和谷嘴子岩组、矿化蚀变等相关成矿信息的表达,厘定了崇礼幅中太古代、新太古代的变质深成侵入体,划分了海西期、印支期、燕山期的岩浆岩建造类型,划分了张家口组火山岩的7个建造类型、谷嘴子岩组变质岩的3个建造类型,系统总结了该区金矿的成矿地质体、成矿构造及成矿结构面、成矿作用特征标志。该数据库为该区金矿的找矿工作提供了基础数据支撑,对金矿目标层地质信息和构造建造信息的提取提供了便利条件,对今后矿产勘查部署具有一定的参考价值。  相似文献   

青海共和盆地中三叠世花岗岩组合岩石成因:地球化学、锆石U-Pb年代学及Hf同位素约束   总被引：1，自引：1，他引：0  

陈希节  贠晓瑞  雷敏  蔡志慧  张盛生  刘若涵  李毅兵  何碧竹 《岩石学报》2020,36(10):3152-3170

青海共和盆地位于青藏高原东北缘,以往有关共和盆地及邻区早-中三叠世岩浆岩成因机制的认识分歧较大,且研究主要集中在露头岩石方面。本文以共和盆地干热岩GR1井深部花岗岩岩芯样品作为研究对象,对其进行岩石学、长石电子探针、主微量元素地球化学、锆石U-Pb年代学及Lu-Hf同位素研究。矿物组成及长石电子探针测试结果显示花岗岩主要为奥长花岗岩、英云闪长岩及花岗闪长岩。锆石U-Pb测年结果表明,奥长花岗岩的结晶年龄为236.5±1.7Ma,英云闪长岩的岩浆结晶年龄为241.6±3.0Ma。主、微量元素地球化学显示这些花岗岩主要为准铝质,属于高钾钙碱性系列。全岩Ta-Nb-Hf等不相容元素图解及锆石Hf同位素数据表明共和盆地的236.5~241.6Ma花岗岩显示火山弧及同碰撞花岗岩成分特征,说明中三叠世共和地区发生俯冲-碰撞转换。结合本文数据与区域背景资料,作者认为：共和盆地早-中三叠世花岗岩组合的形成与印支期宗务隆洋的南向俯冲作用密切相关,此时,在宗务隆-青海南山-西秦岭北缘存在统一的大陆边缘弧环境;在236~241Ma时发生俯冲-碰撞转换;晚三叠世时宗务隆-青海南山-西秦岭北缘已处于碰撞期和后碰撞期。  相似文献   

A natural gas hydrate-oil-gas system in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau     

《China Geology》2020,3(4):511-523

Natural gas hydrate, oil and gas were all found together in the Qilian Mountain permafrost area, northeast of Qinghai-Tibet Plateau, China. They are closely associated with each other in space, but whether they are in any genetic relations are unknown yet. In this paper, a hydrocarbon gas-generation series, gas-fluid migration series and hydrocarbon gas-accumulation series are analyzed to probe the spatial, temporal and genetic relationships among natural natural gas hydrate, oil and gas. The subsequent results show that natural gas hydrate, oil and gas actually form a natural gas hydrate-oil-gas system. Based on the Middle Jurassic and the Upper Triassic hydrocarbon gas-generation series, it is divided into four major sub-systems in the study area: (1) A conventional Upper Triassic gas-bearing sub-system with peak hydrocarbon gas-generation in the late Middle Jurassic; (2) a conventional Middle Jurassic oil-bearing sub-system with low to mature hydrocarbon gas-generation in the late Middle Jurassic; (3) a natural gas hydrate sub-system with main gas source from the Upper Triassic gas-bearing sub-system and minor gas source from the Middle Jurassic oil-bearing sub-system as well as little gas source from the Middle Jurassic coal-bed gas and the microbial gas; (4) a shallower gas sub-system with microbial alteration of the main gas source from the Upper Triassic gas-bearing sub-system. This natural gas hydrate-oil-gas system and its sub-systems are not only theoretical but also practical, and thus they will play an important role in the further exploration of natural gas hydrate, oil and gas, even other energy resources in the study area.  相似文献   

Main progress and prospect for China's hydrogeological survey          下载免费PDF全文

WU Ai-min  HAO Ai-bing  GUO Hai-peng  LIU Jing-tao  ZHANG Er-yong  WANG Huang  WANG Xin-feng  WEN Xue-ru  ZHANG Cui-guang 《地下水科学与工程》2020,8(3):195-209

This paper reviewed the main achievements of hydrogeological survey in China, summarized the significant progress of hydrogeological survey over the past decade, and forecasted the key responsibilities for hydrogeological survey in the p14th Five-year Planq. The significant progress includes: China established the 1: 50 000 standard hydrogeological survey system with Chinese characteristics and produced the new generation of high-quality hydrogeological maps; the national groundwater monitoring project was completed and accepted, which marks China taking the leading position in groundwater monitoring internationally; fruitful results were achieved in the national groundwater quality survey, and groundwater quality background values were basically identified and checked; hydrogeological and environmental geological survey was continuously promoted in karst areas and the ecological restoration of rocky desertification achieved remarkable results; China strengthened layer exploration techniques for groundwater, integrating the key and practical techniques of layer exploration and monitoring; the exploration of groundwater in the poverty-stricken regions and old revolutionary base areas were effectively promoted to strongly guarantee the poverty alleviation and drinking water safety; the mystery of desert groundwater was uncovered, making up for the shortage of 1: 250 000 hydrogeological survey in the Badain Jaran Desert; and more efforts were made to conduct survey on the water resources in the basin, and to finish the unified measurement of national-scale groundwater level.  相似文献   

利用远震研究四川盆地及其周缘瑞利面波相速度和方位各向异性          下载免费PDF全文

王小龙  雷兴林  马胜利  张烨  郭志  闻学泽 《地球物理学报》2020,63(2):445-459

基于四川盆地及周边的245个宽频带台站2010年9月—2014年9月期间的远震记录,提取双台路径瑞利面波相速度频散资料,反演得到四川盆地20～120s的高分辨率瑞利面波相速度及各向异性空间分布.在丰富区域地球物理基础数据的同时,结合已有研究成果对地壳上地幔变形耦合进行探讨,结果表明短周期(20～30s)的相速度分布与四川盆地的地质构造特征相吻合,作为川滇地块、松潘—甘孜地块和四川盆地之间的边界——龙门山断裂带和鲜水河断裂带对上述三个地块上地壳的速度结构具有明显的控制作用;松潘—甘孜地块,特别是川滇地块中下地壳普遍表现为明显的低速异常,表明中下地壳相对软弱;而四川盆地的中下地壳整体呈现相对高速,表明四川盆地具有相对坚硬的中下地壳.研究区域东南角接近北扬子地块与南扬子地块的缝合部位,呈现高速异常.四川盆地南部和东南邻区不同周期均具有较强的各向异性,且快波方向较为一致,反映这些地区不同深度变形耦合较好.四川盆地西部、北部及东北部邻区,不同周期的各向异性快波方向变化较大,不同深度变形耦合较差.这些特征与绕喜马拉雅东构造结的物质流动被扬子地块的高速地壳阻挡的宏观认识基本一致.  相似文献