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电磁频率测深法与地电化学法是当前世界上发展迅速的2种探测深度很大的物化探方法。电磁频率测深法按所用的场源不同又分为天然场源及人工场源法。由于该类方法具有频率范围宽、探测深度大、测量参数多以及分辨率高等特点，现已广泛用于金属与非金属矿产探查、工程及水文地质调查及上地幔的研究中。地电化学法的常用方法有5种：电提取法（CHIM）、接触极化曲线法（KSPK）、非接触极化曲线法（BSPK）、有机络合物法（MPF）及热磁法（TMGM）。这些方法通常在常规化探方法不能取得明显效果的地区用于探查金属矿，其中KSPK法及BSPK法用于探查金属矿体的规模及矿物种类，其他方法用于探查深部金属盲矿体。 相似文献
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时间谱电阻率法中的剩余电磁效应研究 总被引：2，自引：0，他引：2
根据频谱激电（SIP）法或复电阻率（CR）法中研究剩余电磁（REM）效应的思想，通过分析时间谱电阻率（TSR）法中场的基本特征，在TSR法中建立了与SIP（或CR）法中参数Φmax/Φ0max相类似的参数－Emax/E0，用来描述了TSR法中的REM效应。通过对一维可极化大地模型的REM效应的理论计算，验证了用Emax/E0表示的REM异常可用来形象地反映地电断面电阻率的高低。 相似文献
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简要阐述了航测解析法获取地理信息系统空间数据（ 数字地形图） 的过程, 以及此方法在国民经济其他领域的应用。实践表明, 利用航片（ 卫片） , 采用航测解析法可以实时、准确地提取地表地形信息和各类专题信息。 相似文献
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这里引入在工程电磁场（EEF）中使用的新型等效源法（NESM）,并给出了新型等效源法模拟感应测井响应的理论推导及处理过程,模拟了感应测井在不同地质条件下的响应。新型等效源法是在广义多级技术（GMT）的基础上发展起来的,具有理论推导简单,计算速度快,计算精度高等优点。新型等效源法是半解析解法,占用计算机内存少。另外,解的可导性和光滑性比有限元法更胜一筹。采用新型等效源法对感应测井的响应进行数值模拟,并把数值模拟的结果和数值模式匹配法（NMM）进行对比,验证了新型等效源法可行性,并且精度可以随着等效源和级数项的增加而提高。新型等效源法形成的矩阵条件数比较大,应用双精度求解可以增加稳定性。 相似文献
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基于滑移线场理论,按边坡坡面变形量评价其稳定性,提出均质边坡极限曲线法。该法是求有重边坡极限荷载的逆过程,也是强度折减法的对偶过程。以特征线法差分方程组（SCM）和试验方程近似公式（CCM）求得的极限坡面曲线与坡面线相交为变形破坏准则,定义了安全度（DOS）和破坏度（DOF）2个评价指标。该方法不必假设和搜索临界滑动面。经典考题和典型算例的验算表明,随着节点的增加SCM法计算精度增加,边界步长不变时,3次样条插值求得的变形破坏准则判断值不变,说明SCM算法稳定。典型算例的计算数据和图例表明,边坡角变大时边坡稳定性降低,极限坡面曲线与坡面由无交点变为有交点,证明了变形破坏准则的正确性。由2个例题计算结果对比可知,安全系数较大时,SCM法、CCM法计算结果与其具有可比性,相对于原边界条件增加了外荷载;安全系数变小时,SCM法、CCM法偏于保守。34个样本计算正确率为安全系数法67.7%,应力状态法73.5%,CCM法79.4%,SCM法70.6%,表明SCM法和CCM法正确率较高,计算结果可靠,SCM法、CCM法因素敏感性分析结论与安全系数法完全一致。在露天矿边坡稳定性和最终边坡角的分析与计算中,SCM法、CCM法结论与原报告相同,当参数变小时CCM法更有利于实践,具有一定的工程应用价值。 相似文献
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选取威远海相页岩（1#）、焦石坝海相页岩（2#）、瑶曲凝灰岩（4#）及瑶曲陆相页岩（5#和6#）,采用场发射扫描电镜（FE-SEM）与低场核磁共振（NMR）,研究中国海相页岩和陆相页岩之间的孔隙结构特征的差异化特征。核磁共振冻融法（NMRC）可以精细探测页岩的纳米范围的孔隙结构。该方法可以拓展到结合核磁共振弛豫分析进行微观测量,详细探测不同孔径尺度下页岩的孔隙结构。测试温度梯度变化越小,孔隙分布测量的结果越精细。测试结果表明,从样品5#,2#,6#,1#至样品4#的孔隙率逐个减小。NMRC,LFNMR,压汞法（MIP）,气体吸附法（GA）在它们各自的有效测量范围内,孔径分布表现出良好的一致性。因此,将NMRC,LFNMR与GA和MIP等方法组合,可以更准确地评估储层页岩的孔隙结构。研究结果表明,陆相页岩（5#瑶曲页岩）的纳米孔隙更发育,与海相页岩相比也许具有更高的商业开发价值。 相似文献
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本文介绍了林西矿采用无线电波透视法提高小断层探测的准确性与可靠性的四个方面的实验研究：（１）提高数据采集的准确性；（２）提高观测数据量；（３）坑道透视环境与透视工作方法；（４）坑道透视与地质相结合。 相似文献
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详细介绍了无网格伽辽金法（EFGM）基本原理,并将其应用于非均质多孔介质中的稳定地下水流问题,用具体算例将无网格伽辽金法计算结果与传统有限元法（LFEM）计算结果作比较,计算表明无网格伽辽金法具有较高的精度。 相似文献
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瞬变电磁法、时间域激电法在勐兴铅锌矿的应用 总被引：2，自引：0，他引：2
勐兴铅锌矿矿石品位低，埋深大，且面临资源匮竭。采用瞬变电磁法（TEM）和激电法（IP），合理布线展网，反复印证，得到多个物探组合异常。异常源位于下志留统下仁和桥组。经钻孔验证，获得相当于原保有储量3倍的新储量，找矿效果突出。 相似文献
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G. M. van Essen S. Kahrobaei H. van Oeveren P. M. J. Van den Hof J. D. Jansen 《Computational Geosciences》2016,20(5):1061-1073
We present a method to determine lower and upper bounds to the predicted production or any other economic objective from history-matched reservoir models. The method consists of two steps: 1) performing a traditional computer-assisted history match of a reservoir model with the objective to minimize the mismatch between predicted and observed production data through adjusting the grid block permeability values of the model. 2) performing two optimization exercises to minimize and maximize an economic objective over the remaining field life, for a fixed production strategy, by manipulating the same grid block permeabilities, however without significantly changing the mismatch obtained under step 1. This is accomplished through a hierarchical optimization procedure that limits the solution space of a secondary optimization problem to the (approximate) null space of the primary optimization problem. We applied this procedure to two different reservoir models. We performed a history match based on synthetic data, starting from a uniform prior and using a gradient-based minimization procedure. After history matching, minimization and maximization of the net present value (NPV), using a fixed control strategy, were executed as secondary optimization problems by changing the model parameters while staying close to the null space of the primary optimization problem. In other words, we optimized the secondary objective functions, while requiring that optimality of the primary objective (a good history match) was preserved. This method therefore provides a way to quantify the economic consequences of the well-known problem that history matching is a strongly ill-posed problem. We also investigated how this method can be used as a means to assess the cost-effectiveness of acquiring different data types to reduce the uncertainty in the expected NPV. 相似文献
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Size and stress gradient effects on fracture around cavities 总被引：1，自引：2，他引：1
B. J. Carter 《Rock Mechanics and Rock Engineering》1992,25(3):167-186
Summary The effect of hole size on fracture initiation around cavities in rock is examined through physical model tests on Tyndall limestone. Twenty five models, employing nine different hole sizes, ranging from 3.2 to 62 mm in diameter were tested in uniaxial compression. Strain gauges placed both on the face of the model block and inside the cylindrical cavity were used to record the state of fracture.Fracture initiation data for primary, remote and sidewall fractures were determined using the stress-strain curves from the respective strain gauge locations. For all three fracture types, the initiation stress decreases with increasing hole size and appears to approach a horizontal asymptote for large cavity sizes. The fracture mechanics formulations and the stress averaging method give the best fit to the primary fracture initiation except for very small cavity sizes. The stress averaging method also provides a very good fit to the sidewall fracture initiation data. 相似文献
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锚索桩的主动支护作用及桩身初始内力分析 总被引：1，自引：0，他引：1
预应力锚索桩在桩身施工完毕且锚索施加了初始预应力时,因滑坡推力未及作用于桩上,初始预应力即刻对受荷段桩背的岩土体产生迎滑动方向反推的一种主动支护效应,同时使桩身产生初始内力。基于受荷段桩背岩土水平反力模数为常数的单向Winkler弹性地基梁模型,以及嵌入段桩周岩土水平反力双参数模式的Winkler弹性地基梁模型,以受荷段桩身挠曲线的有限差分式与嵌入段挠曲线的解析通解改进式在滑面处的协调条件联立,推导了锚索初始预应力所产生主动支护效果的半解析定量计算和桩身初始内力求解方法,该方法有助于建立应急抢险或施工期,锚索桩工程对滑坡稳定性及时作用的评估。 相似文献
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区域次生地球化学负异常模型及其意义 总被引：7，自引：0，他引：7
原生地球化学负异常的研究已经引起重视,特别是前苏联的化探工作者还总结出利用地球化学原生负异常对热液矿床进行普查和评价的准则.但是,由于缺乏可供对比的划分负异常的适当方法,使得对负异常的研究不能系统化,研究结果也不能互相对比,尤其是对于区域水系沉积物测量中发现的负异常研究很少.本文通过对几个地区衬值负异常的分析,系统地探讨了区域性负异常的分布特征、负异常与正异常的关系、负异常的地质意义和找矿信息等.总结出单元素和多元素区域负异常的分布模型.建立了AU和Cu矿床的区域正负、异常模型.提出了地球化学异常是由正异常和负异常组成的. 相似文献
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The integration of geological and geometallurgical data can significantly improve decision-making and optimize mining production due to a better understanding of the resources and their metallurgical performances. The primary-response rock property framework is an approach to the modelling of geometallurgy in which quantitative and qualitative primary properties are used as proxies of metallurgical responses. Within this framework, primary variables are used to fit regression models to predict metallurgical responses. Whilst primary rock property data are relatively abundant, metallurgical response property data are not, which makes it difficult to establish predictive response relationships. Relationships between primary input variables and geometallurgical responses are, in general, complex, and the response variables are often non-additive which further complicates the prediction process. Consequently, in many cases, the traditional multivariate linear regression models (MLR) of primary-response relationships perform poorly and a better alternative is required for prediction. Projection pursuit is a powerful exploratory statistical modelling technique in which data from a number of variables are projected onto a set of directions that optimize the fit of the model. The purpose of the projection is to reveal underlying relationships. Projection pursuit regression (PPR) fits standard regression models to the projected data vectors. In this paper, PPR is applied to the modelling of geometallurgical response variables. A case study with six geometallurgical variables is used to demonstrate the modelling approach. The results from the proposed PPR models show a significant improvement over those from MLR models. In addition, the models were bootstrapped to generate distributions of feasible scenarios for the response variables. Our results show that PPR is a robust technique for modelling geometallurgical response variables and for assessing the uncertainty associated with these variables. 相似文献
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砂岩储层中原生孔隙的破坏与保存机制研究进展 总被引：2，自引：1，他引：1
埋藏条件下原生孔隙的破坏与保存机制是含油气盆地砂岩储层质量研究的一个核心领域,其在油气地质学研究中的意义不言而喻。与次生孔隙的形成与保存机制相比,影响原生孔隙破坏与保存的因素有着其特殊的复杂性和多样性。在总结国内外研究进展的基础上,试图深入理解不同成岩机制在砂岩储层原生孔隙破坏与保存中的意义和作用,包括破坏机制（如机械压实、胶结作用等）和保存机制（如地层超压、颗粒包膜、盐体侵位和烃类占位等）。目前难以实现砂岩储层质量钻前准确预测的一个困难在于无法明确原生孔隙演化的动力和过程,将来成岩作用、流体作用、沉积过程和盆地演化的更紧密结合可能是解决砂岩储层原生孔隙破坏与保存机制研究中最有希望的发展方向之一。 相似文献
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陆上中基性基性熔岩流单元剖面结构相模式初探 总被引：1，自引：0，他引：1
熔岩是地层剖面中常见的岩石类型,在我国东部中新生代陆相断坳型含油气盆地中,通常形成良好的油气储层。本文在详细研究山东昌潍坳陷下第三系厚层中基性熔岩流复合体岩心基础上,认识到一个完整的陆上熔岩流单元在剖面上通常具备“五段式”结构,即由下向上依次由A、B、C、D、E岩相段组成。分别建立了原生、风化及沉降3种熔岩流单元相模式,并提出通过绘制气孔含量曲线识别熔岩流复合体中熔岩流单元及单元中各岩相带的方法。从而不仅与传统的“三带”、“四带”认识相比更加先进,而且对火山岩油气储层特征研究、垂向模式建立以及测井资料地质解释等具新的指导意义。 相似文献
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In situ ecosystem gas exchange measurements were taken monthly for a 15-month period during low tide forJuncus roemerianus Scheele and short, medium, and tall height forms ofSpartina alterniflora Loisel. in three salt marshes near Southport, North Carolina. Multiple regression analysis was used to obtain empirical relationships betwen gas exchange values and the physical and biotic variables measured. Preliminary models for net ecosystem photosynthesis, ecosystem respiration, and respiration of aboveground standing crop were developed. Validation of models was carried out in the following manner: (1) net primary productivity of aboveground standing crop was calculated from model data and compared with harvest estimates of net primary productivity for the same year; and (2) carbon exchange and energy efficiency values were compared with literature values. In general, theSpartina models, because of their larger data base, were more useful than theJuncus models. Annual primary productivity of aboveground standing crop calculated from gas exchange values was 1.8 to 3.6 times greater forSpartian than values calculated from harvest data by Smalley's method.Juncus values were approximately equal. Since values calculated from carbon data and harvest data are not entirely equivalent, required adjustments to the carbon values are discussed. Both species have two growth periods—one in ths pring and one in the fall—with the spring growth in excess of that in the fall. Net ecosystem productivity was highest in the spring and lowest in the summer. Ecosystem respiration amounted to 71% of gross annual photosynthesis. The aboveground standing crop contributed approximately 35% to this ecosystem respiration and the soil, the remaining 36%. Efficiency for gross photosynthesis per unit of solar radiation ranged from 0.22 to 1.11%. Efficiencies for net primary production of aboveground standing crop ranged from 0 to 0.82% and those of net ecosystem production from 0 to 0.56%. 相似文献