共查询到19条相似文献,搜索用时 79 毫秒
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这里提出以代表质量守恒的反应对流扩散方程作为主控方程的烃类垂向微渗漏方程组的差分格式,即双向一维分裂校正差分格式,并建立地层积木块模型对该格式的边界进行讨论。差分格式是预估~校正差分格式的一种改进形式,它融合了Crank-Nicolson格式、交替方向隐格式、预估~校正差分格式的特点,具有二阶差分精度,且无条件稳定。由于差分格式将每一步都归结为求解三对角线方程组,因此适合并行运算。数值实验表明,应用差分格式的数值模拟结果符合烃类垂向微渗漏过程的理论模型,可作为烃类垂向微渗漏过程分析的计算方法。 相似文献
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烃类垂向微渗漏及其地表异常显示 总被引:8,自引:3,他引:8
烃类以微泡、水动力、扩散和渗透方式向地表迁移过程中,其效能、方式与油气藏的盖层、断裂与裂隙系统、储层的流体性质、地层压力等地质因素密切相关.通过对塔里木盆地雅克拉凝析气田上的地表、井中化探资料与地质资料的综合分析,认为该气田的井中垂向地球化学特征、控制烃类垂向微渗漏地质因素、地表化探异常显示之间呈现出很好的内在联系. 相似文献
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克拉通盆地内油气垂向微渗漏的烃类地球化学──以鄂尔多斯盆地城川1井为例 总被引:1,自引:0,他引:1
通过对鄂尔多斯盆地腹部城川1井(0─4500m)酸解烃、热解烃及部分层段抽提烃的系统研究,结合剖面上有机质含量的变化及产油气层的分布,讨论了油气垂向微渗漏在浅层沉积层中留下的可识别的地球化学痕迹。该井浅层0─1020m井段,有机碳含量低,在0.06%─0.3%之间,平均为0.11%,t(max)值小于400℃,有机质处于未成熟热演化阶段,岩性发育以红色、砖红色粉砂岩和浅灰色砂质泥岩和粉砂岩为主,这样一套沉积组合显然不利于有机质转化成烃。但与其下伏相邻成熟层段相比,S1/TOC,S1/(S1十S2)和C(2+)/TOC均异常偏大,饱和烃的OEP值为1.11─1.13,饱/芳值为5.2─6.4,显示了不具有奇偶优势的成熟烃的特征;经丙烯均一化之后,浅层甲烷和重烃异常并未消失,表明有深部热成因气态烃的加入。盆地内断裂不发育,则通过岩石中微裂隙和孔隙系统的油气微渗漏是深部油气运移的主要方式。由此可见,油气垂向微渗漏在浅层沉积层中留下了可识别的地球化学痕迹。 相似文献
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试论地球化学场的研究方法 总被引:5,自引:0,他引:5
地球化学场的分析与研究是目前勘查地球化学面临的主要问题和关键科学技术之一,在以往研究工作基础上提出了地球化学场的研究指导思想、研究方法,包括有基础地质地球化学研究、区域地质-地球物理-地球化学编图、地球化学场空间结构研究、地球化学区划。 相似文献
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基于“元素含量-面积”模型方法的地球化学场的多重分形模式分析 总被引:1,自引:0,他引:1
从多重分形理论出发,在赤峰地区的2个区域应用“元素含量-面积(C—A)”模型方法。对“元素含量-面积”双对数图的形态进行分析,将地球化学异常多重分形特征模式分为3种类型:模式Ⅰ为可拟合为2条直线段的简单多重分形模式,具有该模式的元素在研究区内没有成矿富集的趋势,不存在实质性的致矿异常;模式Ⅱ为可以拟合为3条直线段的高富集多重分形模式,它在模式Ⅰ的基础上叠加有高含量的异常场,具有该模式的元素在研究区内存在较强的局部富集,成矿的可能性很大:模式Ⅲ为可拟合成3条直线段的低富集多重分形模式,它在模式Ⅰ的基础上叠加的是较弱的异常场,具有该模式的元素在研究区内有较弱的矿化作用。在此基础上,分析了元素的成矿富集规律和空间分布特征,确定了区域异常和局部异常的异常下限,划分了地球化学背景、区域异常和局部异常。 相似文献
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从多重分形理论出发,在赤峰地区的2个区域应用"元素含量-面积(C-A)"模型方法.对"元素含量-面积"双对数图的形态进行分析,将地球化学异常多重分形特征模式分为3种类型:模式Ⅰ为可拟合为2条直线段的简单多重分形模式,具有该模式的元素在研究区内没有成矿富集的趋势,不存在实质性的致矿异常;模式Ⅱ为可以拟合为3条直线段的高富集多重分形模式,它在模式Ⅰ的基础上叠加有高含量的异常场,具有该模式的元素在研究区内存在较强的局部富集,成矿的可能性很大;模式Ⅲ为可拟合成3条直线段的低富集多重分形模式,它在模式Ⅰ的基础上叠加的是较弱的异常场,具有该模式的元素在研究区内有较弱的矿化作用.在此基础上,分析了元素的成矿富集规律和空间分布特征,确定了区域异常和局部异常的异常下限,划分了地球化学背景、区域异常和局部异常. 相似文献
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秦岭造山带古热水场地球化学类型及流体动力学模型探讨——热水沉积成矿盆地分析与研究方法之二 总被引:3,自引:2,他引:3
采用地质类比方法, 结合秦岭造山带热水沉积岩相研究, 提出热水沉积体系概念。通过现代陆相及海相热泉和秦岭热水沉积岩相对比, 按化学成分可将古热水场划分为强酸性硫酸盐型、弱酸强碱碳酸盐型、以SiO2 为酸酐型、碱性富Mg 重卤水型、热卤水型及强酸性硼硅酸盐型等6 种类型古热水场。并对典型热水场的地球化学类型特征及成岩成矿作用进行了讨论。在前人研究的基础上, 探讨了热水系统的流体地球化学动力学。提出了热水沉积成矿盆地中热水系统的两类地球化学流体动力学模型, 热水层流体系模型和不同成分、性状的热水混合体系模型。从热水系统的边界协同学约束条件、空间拓朴结构、流体通量动量方程及矿质大规模沉淀的地球化学动力学等方面对这两类流体动力学模型进行了讨论。 相似文献
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Ji Kejian Wang Liben Lu Fengxiang Wang Wuyi Zhang Jianhua Institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing 《《地质学报》英文版》1993,67(2)
Primary haloes of hydrothermal deposits were previously considered as positive haloes. Although it has been recently suggested that primary haloes incude positive and negative ones, almost all the research work on primary haloes has still focused on positive haloes for various reasons. In order to understand the source of ore substances a number of large hydrothermal deposits related to magmatism including porphyry, skarn and vein type deposits have been studied. It has been found that negative haloes exist on the peripheries of positive haloes of a mineral deposit. On the basis of the study the authors propose the concept of the geochemical field system of ore-forming elements of hydrotherreal deposits, i. e., with the orebody as the centre outwards there occur the mineralized field, positive halo field, depleted field and background field successively. 相似文献
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Abstract Primary haloes of hydrothermal deposits were previously considered as positive haloes. Although it has been recently suggested that primary haloes incude positive and negative ones, almost all the research work on primary haloes has still focused on positive haloes for various reasons. In order to understand the source of ore substances a number of large hydrothermal deposits related to magmatism including porphyry, skarn and vein type deposits have been studied. It has been found that negative haloes exist on the peripheries of positive haloes of a mineral deposit. On the basis of the study the authors propose the concept of the geochemical field system of ore-forming elements of hydrothermal deposits, i. e., with the orebody as the centre outwards there occur the mineralized field, positive halo field, depleted field and background field successively. 相似文献
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The formation mechanisms and processes of geochemical anomalies used as proxies in surface geochemistry exploration (SGE) have not been well understood. Previous studies cannot realize 3D measurement of microseeping hydrocarbons from reservoirs to the surface, which made it difficult to understand the features and pathways of deep hydrocarbon microseepages. Understanding the processes of hydrocarbon microseepages will contribute to the acceptance and effectiveness of surface geochemistry. Based on a simplified geological model of hydrocarbon microseepages, including hydrocarbon reservoir, direct caprock, overlying strata and Quaternary sediments, this work established a 3D experimental system to simulate the mechanisms and processes of deep hydrocarbon microseepes extending to the surface. The dispersive halos of microseeping hydrocarbons in the subsurface were adequately described by using this 3D experimental system. Results indicate that different migration patterns of hydrocarbons above the point gas source within the simulated caprock and overlying strata can be reflected by the ratio of i-butane to n-butane (i-C4/n-C4), which follow diffusion and infiltration (buoyancy) mechanisms. This is not the case for vertical measurement lines far from the point gas source. A vertical gas flow in the form of a plume was found during hydrocarbon microseepage. For sampling methods, the high-density grid sampling is favorable for delineating prospecting targets. Hydrocarbon infiltration or buoyancy flow occurs in the zones of infiltration clusters, coupling with a diffusion mechanism at the top of the water table and forming surface geochemical anomalies. These results are significant in understanding hydrocarbon microseepage and interpreting SGE data. 相似文献
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Based on a conceptual model of hydrocarbon microseepage, a macro-sized experimental equipment used the matched mixtures of cement and quartz sand as simulated caprock and its overlying strata is first set up to simulate the processes of hydrocarbon microseepage and its near-surface expressions. The results of the simulation experiments suggest that simulated caprock and its overlying strata have a certain sealed capability; hydrocarbon microseepage is dominated by the pressure of point gas source, and temperature plays only a subordinate role; on the path of hydrocarbon microseepage, the distribution of hydrocarbon concentration is fan-shaped; differential adsorption of alkanes by the simulated caprock and its overlying strata results in the occurrence of a chromatographic effect. Different migrating patterns within simulated caprock are shown by the ratio of i-butane to n-butane. The concentration of hydrocarbon in the surface soil has good correspondence with the pressure of point gas source. These simulation results are significant to further study of the mechanism of anomalies recovered in surface geochemistry exploration. 相似文献
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WangChaoyong XiaWenchen 《中国地质大学学报(英文版)》2002,13(1):48-52
The qualities of petrology and paleobiology in Wuzhishan Section are studied.Several geo-chemical anomalies are recognized,such as:high rare earth element content ,high pyrite content and Ni anomalies.It could be correlated with Nandong Section in Xiangzhou County and the F/F boundary could be determined according to Ni anomalies.The results of the study indicate indicate that the geochemical anomaly plays an important role in stratigraphic correlation in non-fossil stratum. 相似文献
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SHI Changyi ZHANG Jinhua China University of Geosciences Beijing Institute of Geophysical Geochemical Exploration Langfang Hebei 《《地质学报》英文版》2003,77(1):72-80
Regional stream sediment surveys at a 1:200,000 scale reveal positive and negative regional multi-element geochemical anomalies over medium to large copper-polymetallic orefields of different genetic types in China. Regional geochemical anomalies of orefield refer to those geochemical anomalies that are related to metallogenesis of an orefield in a certain area. The anomaly area is typically 10 to 100 km2. The regional multi-element anomalies related to mineralization can be divided into three groups, that is, the ore-element anomaly association, indicator element anomaly association, and metallogenic environmental element anomaly association. Their common spatial distributions over ore deposits or orefields possess unique structures.The model of spatial structure of regional multi-element geochemical anomalies (RAGSS) of an orefield delineates structural feature possessed by orderly spatial distributions of different groups of multi-element anomaly associations related to orefield metallogenesis. It is 相似文献
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Application of Wavelet Analysis to Interference Elimination for Geochemical Hydrocarbon Exploration 总被引:3,自引:0,他引:3
Zhang Liuping Ruan Tianjian Faculty of Earth Resources China University of Geosciences Wuhan 《中国地质大学学报(英文版)》2000,11(1)
INTRODUCTIONElimination of interferences (e.g. background variation)is the base of anomaly recognition in geochemical exploration.The interference elimination was performed by using thevariables that could indicate interference factors (L iu andZhao,1992 ) . As some variables such as carbonates and p Hcontain information on both interference and hydrocarbons,some information on hydrocarbons may be lost while theinterference is eliminated. Besides,this approach is not cost-effective becau… 相似文献
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远洋沉积物是多金属结核赖以生长的场所,本文系统地研究了沉积物中主要成矿元素水成组分在不同地球化学场和不同沉积阶段的地球化学特征,以及水成组分的含量比与成矿作用的相互关系。研究表明,Mn、Fe、Co、Ni、Cu都是一些比较活泼的元素,它们共处于多金属结核、沉积物和大洋水的统一体系中,当结核形成时,Mn、Fe、Ni、Cu在结核与沉积物中的含量呈负相关,而Co含量呈正相关。研究区东部结核以富含Mn、Ni、Cu贫Fe、Co为特征,其伴生沉积物相对贫Mn、Ni、Cu、Co,而富Fe,可称之为贫化的地球化学场。研究区西部结核富含Fe、Co而贫Mn、Ni、Cu,其伴生沉积物则相应贫Fe,而富Mn、Ni、Cu、和Co,可称之为富化的地球化学场。可以看出,贫化的沉积物地球化学场,恰恰是寻找富矿结核的最佳场所。早中新世以来的沉积物,根据水成组分的含量或含量比,也可相应于结核的形成分为三大沉积阶段,其中的第Ⅱ阶段具有贫化的地球化学特征,是多金属结核形成的最有利时期 相似文献