共查询到20条相似文献，搜索用时 46 毫秒
1.
I. Lerche 《Mathematical Geology》1991,23(6):817-832
Present-day observed downhole quantities, which a dynamical model of basin evolution should account for, include: total depth drilled, formation thicknesses, variations of porosity, permeability and total fluid pressure with depth, and depths of unconformities. Following a line of logic previously employed with multiple thermal indicators, it is shown how the observed quantities can be used in a nonlinear inverse sense to determine, or at least constrain, parameters and functions entering quantitative models of dyanmical sedimentary evolution. A procedure is given so that the inverse methods can be used: (a) with single well data; (b) with multiple well data; and (c) simultaneously with thermal indicator data, which have already been previously successfully inverted using a tomographic procedure. Parameters that can be evaluated using the dynamical indicator inversion (dynamical tomography) include, but are not limited to, values dealing with geological events (such as unconformity timing and amount of material eroded, the openness or shutness of faults; critical fracture pressure, etc.), as well as values dealing with intrinsic, or assumed, lithologic equations of state (such as power law values in connections between permeability and void ratio, or between frame pressure and void ratio). The dynamical tomography procedure can be used with or without weighting the data and/or the dynamical indicators; is guaranteed to produce a closer correspondence between predicted and observed behaviors at each nonlinear iteration; and is guaranteed to keep all parameters within any chosen domain. When used in a multiple well setting, the dynamical tomography method enables an assessment to be made of the assumed invariance to spatial location of parameters in equations of state, as well as allowing geologic process parameters to vary with well location. The procedure also automatically incorporates the ability to determine precision, resolution, sensitivity, and uniqueness of any or all parameters, both associated with equations of state and associated with geological processes. Thus, a sharper understanding is achieved of the trustworthiness and uncertainty of quantitative basin analysis models in respect of: (i) intrinsic assumptions of a model; (ii) implicit or explicit parameter dependences for both geological events and imposed functional dependences of variables; (iii) resolution with respect to finite sampling and measurement error or uncertainty in the quality and quantity of observed data. 相似文献
2.
The dynamical evolution of sediments in basins, and their compaction, is the underpinning keystone on which rests the ability to model thermal history of the basin and hydrocarbon generation, migration, and accumulation histories. A presentation is given of the dynamical tomography method, which inverts dynamical indicators to evaluate the parameters in a 1-D fluid-flow/compaction model, including values dealing with geological events as well as values dealing with intrinsic, or assumed, lithologic equations of state. Synthetic tests illustrate the operation of the system. Using observed downhole quantities: total depth, formation thicknesses, variation of porosity, permeability, and total fluid pressure with depth from the Navarin Basin COST No. 1 well, Bering Sea, Alaska, the numerical algorithm was tested and found to be effective in a nonlinear inverse sense to determine and/or constrain the parameters entering quantitative models of dynamical sedimentary evolution. The predictions of present day total depth, formation thicknesses, porosity, permeability, and fluid pressure with depth are close to the measured data. The minimization provides the uncertainty in each parameter and so the geohistory of a well can be defined better. 相似文献
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利用时间分裂的错格伪谱法模拟地震波在基于改进BISQ模型的双相介质中的传播 总被引：1，自引：0，他引：1
改进的BISQ(Biot-Squirt)模型中各参数具有明确的物理意义和可实现性,在不引入特征喷流长度的情况下可将Biot流动和喷射流动两种力学机制有机地结合起来;而高精度的地震波场数值模拟技术是研究双相介质地震波传播规律的重要手段。本文从本构方程、动力学方程和动力学达西定律出发,推导了基于改进BISQ模型的双相各向同性介质的一阶速度--应力方程组;采用时间分裂错格伪谱法求该方程组的数值解,模拟半空间及层状双相介质中的地震波场。数值模拟结果表明:①与传统方法相比,时间分裂错格伪谱法波场数值模拟的精度更高,压制网格频散效果更好;②在非黏滞相界情况下,慢纵波呈传播性,而在黏滞相界情况下,慢纵波呈扩散性,以静态模式出现在震源位置;③双相介质分界面处,各类波型复杂的反射透射规律可由数值模拟结果清晰展现。 相似文献
4.
福建镇海一带玄武岩柱状节理的动力学研究：兼论柱状节理的成因 总被引：5，自引：1，他引：5
根据流体动力学和自组织理论,研究了玄武岩柱状节理形成的动力学特征,并应用福建镇海一带玄武岩平均化学成分,估算出动力学方程中所涉及的参数,求出了断面直径与节理柱体长度之间的函数关系,并用数值计算方法,求出了R_a,d和L的值,其结果与该地区的地质实际基本吻合,最后探讨了柱状节理的成因机理,并把柱状节理的形成过程划分为两个阶段:(1)热耗散-对流阶段,(2)冷却-收缩阶段。 相似文献
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伊犁盆地南缘中新生代构造样式与铀成矿关系 总被引：4，自引：0，他引：4
伊犁盆地是我国最早发现砂岩型铀矿的地区,近十几年来一直保持砂岩型铀矿找矿的不断突破,盆地南缘自西向东查明了一系列砂岩型铀矿床,这些铀矿床的分布与盆地南缘构造关系密切。本文总结了伊犁盆地南缘构造样式类型,分析了不同构造样式下氧化流体补给、运移规律,并结合铀矿体的空间分布,指出构造样式差异是造成砂岩型铀矿体空间分布的关键因素;从氧化流体补给窗的开启、流体的汇聚和还原性气体聚集的控制等方面讨论了构造样式对铀矿体空间定位的机制,指出单斜稳定地层中纵弯背斜是控制铀空间分布的主要构造,要注意不同构造样式约束下成矿区域的稳定型和地下水补给的多样性,在此基础上讨论了伊犁盆地南缘铀矿的找矿方向及主要矿物类型。 相似文献
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成矿流体输运物理机制研究的关键难题与方法体系 总被引：9，自引：0，他引：9
流体的物质来源，流体活化→迁移→聚集→沉淀过程的化学机理，流体输运与定位过程的物理机制，可视为构造-流体-成矿系统这一课题研究中的主要问题。相对于前两个基本方面的研究进展而言，流体的输运与定位过程的物理机制仍然是矿床学研究中一个重要难题。流体输运物理规律的研究方法主要包括定性分析、定量模拟和相似物理实验等。定性分析主要是对大量地质现象的高度概括和科学升华，分析结果表明成矿流体，尤其是多相热流体在给定三维动态形变场中的运移趋势及定位规律是成矿流体输运物理机制研究的关键问题；但由于逻辑推理和经验判断在定性研究中扮演了重要角色，定性研究的结果显得抽象和过于概略，不能详尽地阐明流体输运的物理过程。而定量模拟难以把握成矿期介质渗透率及成矿应力场的动态变化，使其与实际地质对象在物理性质上具有一定差距。物理实验虽能处理二维动态构造形变场中流体输运问题，但由于实验条件的限制，难以处理三维空间内流体运移问题。因而，上述 3种研究手段优势互补，它们的交错应用及结论间的相互对比与验证，将有望解决流体输运与定位过程物理机制研究中的重要问题。 相似文献
9.
John C. Tipper 《Mathematical Geology》1994,26(7):843-855
The Exxon global cycle chart is now widely used as a stratigraphic correlation tool, although it remains a controversial one. It requires continual testing against new data, but tests are difficult at present because the assumptions behind the chart have not so far been precisely specified. Some reasonable assumptions are made here, and a few simple tests are then proposed on the basis of these. Some of these tests are appropriate to specific situations in which the lest data are estimated sequence boundary ages: others are for situations in which sets of undated sequence boundaries are available that are only known to lie within particular parts of the Exxon chart. No general test for the Exxon chart has yet been developed, and the specifications for such a test are discussed. 相似文献
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以位于浙江省三门县蛇蟠岛清风洞古代凝灰岩采石场中的某组结构面（编号分别为J1～J4）为研究对象,利用反分析方法得到了结构面的长期抗剪强度参数：凝聚力c =0.078 MPa,内摩擦角? =15.76°。反分析的具体步骤如下：①假设结构面J1～J4符合摩尔-库仑准则,且岩石为均质弹性和各向同性的;②根据结构面处于极限平衡状态（即稳定性系数k =1）,列出以参数c、? 为未知数的极限平衡方程;③利用FLAC3D进行三维数值计算,并从计算结果中提取求解极限平衡方程所需的数据,并将数据代入上述方程便可得到4个二元一次方程;④求解此矛盾方程组即可得结构面的长期抗剪强度参数c、? 值 相似文献
11.
Based on the Biot theory, the exact solutions for one‐dimensional transient response of single layer of fluid‐saturated porous media and semi‐infinite media are developed, in which the fluid and solid particles are assumed to be compressible and the inertial, viscous and mechanical couplings are taken into account. First, the control equations in terms of the solid displacement u and a relative displacement w are expressed in matrix form. For problems of single layer under homogeneous boundary conditions, the eigen‐values and the eigen‐functions are obtained by means of the variable separation method, and the displacement vector u is put forward using the searching method. In the case of nonhomogeneous boundary conditions, the boundary conditions are first homogenized, and the displacement field is constructed basing upon the eigen‐functions. Making use of the orthogonality of eigen‐functions, a series of ordinary differential equations with respect to dimensionless time and their corresponding initial conditions are obtained. Those differential equations are solved by the state‐space method, and the series solutions for three typical nonhomogeneous boundary conditions are developed. For semi‐infinite media, the exact solutions in integral form for two kinds of nonhomogeneous boundary conditions are presented by applying the cosine and sine transforms to the basic equations. Finally, three examples are studied to illustrate the validity of the solutions, and to assess the influence of the dynamic permeability coefficient and the fluid inertia to the transient response of porous media. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
12.
洪海沟矿床是近年来伊犁盆地南缘发现的大型铀矿床,既有砂岩型工业铀矿体也有煤岩型工业铀矿体。本文从洪海沟矿床地质特征研究入手,分析该地区铀成矿的主控因素,从构造和沉积的角度探讨其对氧化带发育和铀空间定位的约束。研究认为,构造斜坡带中次级隆起为成矿体提供流体的补给与氧化流体运移的动力,构造坡度的变异部位是成矿物质卸载的有利部位。主砂体是氧化流体运移的通道,制约并引导氧化流体的运移方向,砂体变异造成氧化带尖灭并控制着铀矿体的空间定位。氧化流体分带的多样性造成矿体类型和形态的多样,层间氧化带的平面分带性控制着砂岩型铀矿体的产出,氧化流体的垂向分带性控制煤岩型铀矿体的空间产出。 相似文献
13.
地震层析成像方法及其在岩体结构研究中的应用 总被引：13，自引：0，他引：13
根据岩体结构理论 ,软弱结构面对岩体变形与破坏具有优先控制作用 ,它与围岩在地震波传播性质 (波速与衰减特性 )上的差别 ,可以利用地震层析成像技术 ,对它进行空间定位 ,进而研究岩体的内部结构特征。针对岩体结构研究的特点 ,本文提出将地震波走时成像方法与地震波衰减成像方法 (振幅与脉冲宽度 )集成到一个处理流程中 ,实现了岩体结构的综合成像方法。 相似文献
14.
The results of detailed studies and interpretations are presented for composition variations, structural properties and the phase state of hydrocarbon fluids from subsalt pools of the Pre-Caspian depression. These data serve as a basis for substantiating the existence of several types of condensate, and identifying the locations of the main centres of fluid generation. The basic geological-geochemical conditions controlling the composition of condensate and free gases have been determined as well as their present phase state. A set of basic criteria is proposed as well as prognostic maps for the condensate and free gas composition, and the pool phase states. 相似文献
15.
对构件和结构损伤后的力学性能变化研究一直是世界各国学者十分关注的问题。从现有文献得知,大多研究者以损伤力学及断裂力学为基本理论,按照等效应变原理研究结构及构件的损伤。作者根据等效刚度原理定义损伤程度,对损伤采用损伤位置、损伤程度和损伤长度三个参数来描述,从材料力学平面弯曲理论出发,运用小变形的平面弯曲挠曲线近似微分方程,并引入损伤程度的定义,推导出恒载作用下损伤梁转角和挠度方程的隐含表达式。对悬臂损伤梁进行了各种损伤情况下转角和挠度数值计算结果的对比分析,总结出了其位移变化规律。本研究的目的是为了充分有效地认识损伤梁的性能变化,期望为结构的健康检测、损伤识别理论研究奠定基础。 相似文献
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为了研究结构性原状黄土在加载条件下的破坏特性,采用试验的方法对Q2原状黄土进行了非饱和土三轴剪切试验研究。基于试验成果,定义了可以考虑球应力、偏应力和基质吸力等因素的土的结构性变量参数m。利用通过试验提出的m的计算方法,找出抗剪强度参数c、 值与m之间的关系,推导出m与c、 值的曲线方程,分别将曲线方程代入到Drucker-Prager（D-P）准则方程中对其进行修正,建立了结构性Q2原状黄土的修正屈服准则,该准则可以考虑Q2原状黄土的结构性影响,符合黄土的结构性特性,绘制出可反应结构性参数影响的屈服面,并验证了其合理性。 相似文献
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水平井含水率上升影响因素 总被引：1，自引：1，他引：0
利用塔里木油田塔中4油田(TZ4)底水油藏相关的地质、流体数据建立数值模型。在所建模型的基础上,应用数值模拟计算的累积产油、产水和产液量回归俞启泰水驱特征曲线,以反映水平井见水特征的参数b。以参数b为研究对象,采用正交试验的方法研究不同因素对b值的影响,筛选影响水平井见水特征的主要因素,认为原油粘度、油层厚度、非均质性及水平井水平段在油藏中的位置是影响水平井含水上升趋势的主要指标。最后建立主要因素与b值的关系式,结合俞启泰曲线b值图版,提出预测水平井见水规律的公式——图版法(F-b法)。应用F-b法对塔里木水平井含水率进行预测,并与其他相关方法及实际生产数据对比,认为F-b法可作为预测塔里木油田水平井含水率、估算可采储量的一种有效方法。 相似文献
18.
饱水白云岩临界点、骨架和流体弹性参数的数值计算 总被引：2，自引：2，他引：0
基于临界孔隙度模型,提出了用岩石的整体弹性信息反演求取临界点、流体和骨架等局部弹性参数的数值计算方法和双向线性回归计算公式;结合饱水白云岩的样品测试数据,以孔隙度为自变量和因变量,对密度和密度与纵、横波速度平方的乘积分别进行了数值计算。以测试样品的整体信息求得其临界点、流体和骨架弹性参数值,并与实测数据做了相关性分析,其相关系数高达90%,充分表明数值计算公式的正确性和实现方法的有效性。岩石骨架、流体弹性参数的数值反演计算在油气勘探领域中具有巨大潜力,运用测井曲线和地震数据,可以反演求出岩石孔隙中流体弹性参数(密度、速度),对直接指示油层、气层起到重要作用。 相似文献
19.
Reconstruction of geological structures has the potential to provide additional insight into the effect of the depositional history on the current-day geomechanical and hydro-geologic state. Accurate modeling of the reconstruction process is, however, complex, necessitating advanced procedures for the prediction of fault formation and evolution within fully coupled geomechanical, fluid flow and temperature fields. In this paper, a 3-D computational approach is presented that is able to forward model complex structural evolution with multiple intersecting faults that exhibit large relative movement within a coupled geomechanical/flow environment. The approach adopts the Lagrangian method, complemented by robust and efficient automated adaptive meshing techniques, an elasto-plastic constitutive model based on critical state concepts, and global energy dissipation regularized by inclusion of fracture energy in the equations governing state variable evolution. The proposed model is validated by comparison of 2-D plane strain and 3-D thin-slice predictions of a bench-scale experiment, and then applied to two conceptual coupled geomechanical/fluid flow field-scale benchmarks. 相似文献
20.
侧限压缩条件下土体结构性参数的单变量模型 总被引：1，自引：0，他引：1
通过分析侧限压缩条件下基于应变考虑的土结构性参数和基于应力考虑的土结构性参数,给出了结构性参数的统一表达式,即采用割线模量表示的土体结构性参数。这种表示的积极意义在于避免了初始状态下基于应变考虑的土结构性参数和基于应力考虑的土结构性参数均无法求解的现象。构建了以主动作用为单变量描述的土体结构性参数模型,即基于相同应力方法的土结构性参数模型和基于相同应变方法的土结构性参数模型,并对杨凌黄土的原状样、重塑样和饱和样进行侧限压缩试验。通过试验值和计算值的比较,检验了模型的合理性。研究结果表明,试验值和计算值能够较好吻合。采用主动作用为单变量描述的土体结构性参数直观地反映主动作用对土体结构性的影响,同时简化结构性参数计算过程,实现数值计算。 相似文献