裘布依地下水井流计算公式有关问题讨论

在长期的实际工作中发现,抽水井口径对抽水试验成果存在较大影响、传统的裘布依井流公式对井涌水量和水文地质参数计算结果与实际情况偏差较大。本文以不同水文地质条件下岩溶含水层中井抽水试验成果资料为依据,通过统计分析,揭示了井径与井涌水量以及含水层水文参数计算成果之间的相关关系,探讨了裘布依井流计算公式在理论和实践上存在的问题...     

裘布依公式与泰斯公式中渗透系数间的关系

抽水试验分析理论可分为稳定流理论和非稳定流理论两大类,而这两大类理论又分别以裘布依公式和泰斯公式为代表。裘布依公式以简单易懂,使用方便     

流量测井理论基础及其在水文地质工作中的应用

文章概略地讨论了流量测井的物理基础,提出了流量测井唯一性定理,及利用一次混合抽水求取孔内各含水层水文地质参数的水文地质理论,并以实例为基础,讨论了流量测井的技术优势和经济潜力。自法国著名水动力学专家裘布依提出裘布依假设和裘布依公式以后,单层抽注水试验成为各国水文地质工作者评价含水层水动力学参数的主要方法。近百年来的实践证明,这种方法不仅费工、费财、耗费大量能源,而且所获资料并不准确。1978年以来,我们对流量测井理论、仪器及方法技术的研究,正是针对上述问题进行的。六年来的研究工作及大量野外试验证明,流量测并具有较大的技术优势。     

稳定流裘布依公式对误差的传递作用雏议

地下水稳定流是地下水运动的主要形式之一。作者以稳定流理论的裘布依公式为代表，将带有误差的水位降代入裘氏模型求解，公式本身对误差的传递，本文作了一些初步的探讨，这对在实际工作中提高救布依求解水文地质参数，进行水位预报等的精确度，是大有益处的。     

水化学指标表示裘布依公式的应用

从多矿物溶解化学动力学方程出发,推演并建立了由水化学指标表示的承压二维井流裘布依公式。结合水文地质、水文地球化学特征,列举了水文地质单元内不同区带、各种代表性矿物及相应组分化学指标的基本表达式。以山西省太原西峪煤矿所需解决的水文地质问题为例进行了定量研究与评价,其结果与已有的抽水试验资料接近,为矿井涌水量的评价开辟了一条新的道路。从事实上进一步论证了水化学指标表示裘布依公式的理论概括是正确的。     

基岩裂隙区单孔抽水试验渗透系数对比分析

渗透系数的求取量化是水文地质和工程地质工作广为利用的一种方法。本文针对巢湖市地质疗养院一带基岩裂隙分布区的单孔抽水试验资料,分别使用裘布依公式和水位恢复法对渗透系数进行了计算,结果显示：用裘布依公式得到的平均渗透系数为0.144538 m/d,用水位恢复法测得渗透系数为0.142659 m/d。通过实验对比分析,得出水位恢复阶段求取渗透系数比稳定流水位恒定阶段精度高。     

用稳定流方法计算含水层渗透系数中几个问题的讨论

含水层渗透系数是评价地下水资源,拟定开采方案的主要参数之一。用裘布依涌水量方程求得的渗透系数一般偏小,实际是抽水井孔壁附近水位和井内水位之间存在着一个差值,即所谓的水跃值。裘布依在推导“方程”时没考虑水跃值。本文希望通过阐述水跃值的产生及其计算方法来证实水跃值对参数的影响,从而确定准确求参数的方法。     

基于不同孔径钻孔抽水试验求参对比分析

抽水试验是确定含水层水文地质参数,了解水文地质条件的主要方法。水文地质参数计算的精度直接关系到地下水资源评价精度和对区域水文地质条件的认识程度。基于野外抽水试验数据,通过裘布依稳定井流公式法和含水层试验软件Aquifer test计算水文地质参数,将计算结果作比较,以期得到更加精确的水文地质参数。虽然裘布依稳定井流法计算简便,但对水文地质条件概化处理,使得参数计算结果与实际值相差较大;而Aquifer test软件基于严谨的非稳定流理论数学模型,求参准确性相对较高,操作方法简捷。     

裘布依公式的水文地质化学动力学形式

以水文地质化学动力学方程为基础,承压含水层稳定流为例,推演了由水化学指标表示的一维和二维稳定井流的裘布依公式。在讨论化学指标表示的裘布依公式与原公式关系的基础上,结合水文地质、水文地球化学综合模型,讨论和写出不同区带、各种矿物及相应组分化学指标表示的基本方程式。以山西晋城市新矿区抽水试验及相应的水化学指标,讨论了计算步骤和方法。最后讨论了这类公式可以扩展到潜水及非稳定流各种井、渠公式中,以及用水化学指标表示公式的某些实际意义。     

泰斯公式的50年

1935年,在美国地球物理联合会会报上刊登了一篇短文,标题是:“利用地下水贮存量的井引起的水压面下降与井的抽水流量及持续时间的关系”。当时很少有人会想到:正是这篇短文,成了水文地质发展史上一个重要的里程碑,文中提出的公式,被后人冠以论文作者——泰斯的名字,成了非稳定渗流理论开端的标志。 1856年达西定律发表后不久,裘布依等人即以达西定律为基础,推导出了一系列适用于地下水稳定流     

抽水井单位涌水量并不就是含水层导水系数——与兰太权先生商榷

兰太权先生发表3篇文章公布其多年探讨井抽水的单位涌水量和渗透系数或导水系数的关系,认为其提出了一个新的公式和论断“单位涌水量就是导水系数”,并认为传统径向稳定井流理论是错误的,在行业内应改用他提出的新理论、新公式。本文指出其文章中存在的若干问题,说明其公式或理论的不合理和不能用于实际的情形,并阐明抽水井单位涌水量不能等同于含水层导水系数。     

A 3D discrete FEM iterative algorithm for solving the water pipe cooling problems of massive concrete structures

Water pipe cooling has been widely used for the temperature control and crack prevention of massive concrete structures such as high dams. Because both under‐cooling and over‐cooling may reduce the efficiency of crack prevention, or even lead to great harm to structures, we need an accurate and robust numerical tool for the prediction of cooling effect. Here, a 3D discrete FEM Iterative Algorithm is introduced, which can simulate the concrete temperature gradient near the pipes, as well as the water temperature rising along the pipes. On the basis of the heat balance between water and concrete, the whole temperature field of the problem can be computed exactly within a few iteration steps. Providing the pipe meshing tool for building the FE model, this algorithm can take account of the water pipe distribution, the variation of water flow, water temperature, and other factors, while the traditional equivalent algorithm based on semi‐theoretical solutions can only solve problems with constant water flow and water temperature. The validation and convergence are proved by comparing the simulated results and analytical solutions of two standard second‐stage cooling problems. Then, a practical concrete block with different cooling schemes is analyzed and the influences of cooling factors are investigated. In the end, detailed guidance for pipe system optimization is provided. Copyright © 2015 John Wiley & Sons, Ltd.     

煤层气井下排采参数及其诊断仪研制要点思考

针对我国目前煤层气评价、勘探、开发中尚存在的理论和实践问题,探讨了影响煤层气评价的排采井内压力、密度、温度、水气混合液流量等重要参数和各参数在井筒中的曲线应有形态,以及获得各参数的煤层气井下诊断仪的研制思路．达到了解煤层气储层各部分的实际工作状态的目的,为煤层气排采井的产水和产气层位以及气、水单独流量和相应的压力的定性分析提供依据。     

Fracture void structure: implications for flow, transport and deformation

 This review focuses on studies of flow, transport and deformation processes at a scale of a single discontinuity. The paper provides an evaluation of: (1) various methods suggested for geometrical characterization of void structure; and (2) theoretical and practical problems arising from significant differences between the actual geometry of fracture void structure and its parallel plate representation. The use of an equivalent aperture concept is shown to be seriously misleading in: (a) evaluation of flow regime, and hence selection of appropriate flow laws; (b) correlating tracer and hydraulic tests, and assessment of solute transport properties; and (c) relating hydraulic and mechanical apertures, and predicting influence of stress perturbation and deformability. Received: 2 August 1999 · Accepted: 30 November 1999     

泡沫流变模型试验研究

泡沫流变模型是进行泡沫钻井流变和水力参数计算、指导实际作业的理论基础。通过室内精确测试泡沫流过模拟实钻循环管路压差和流速的变化对泡沫流变性进行研究，结果表明，泡沫流体可用幂律假塑性模型和宾汉塑性模型来表征，以幂律假塑性模型最接近实际流变性。     

单井注水改变填埋场中垃圾土温度的模拟

为了加速填埋场降解的稳定化,渗滤液回灌常被应用在工程实践中。使用竖井进行回灌是较为有效的方式之一。伴随着液体的注入,由于对流的产生,垃圾土温度势必会发生改变。基于无锡填埋场注水试验,对该现场试验过程中垃圾土温度的改变进行模拟。为此,建立了考虑渗透系数和孔隙率随深度变化的渗流模型,以及考虑渗流影响的热对流-热传导模型,并利用数值计算方法进行求解。在对比计算值和试验值之后,发现所建立的模型能较好地模拟注水期间渗滤液水位和垃圾土温度的变化规律。结果表明：在离注水井超过6 m处的位置,显现的液位相对滞后,至少滞后0.15 d,而且距离越远滞后的时间越长;在液位以下,注水井周围的垃圾土温度均低于初始温度。但是在径向上远离注水井3.6 m之外的垃圾土温度并不是全低于初始温度,在新老垃圾土交界处之上2 m范围内,会出现温度高于初始温度的现象,温度差可达3 ℃;新填垃圾土的已降解时长对单井注水工况下温度分布的影响较为显著。     

The numerical modelling of advective transport in the presence of fluid pressure transients

Conventional modelling of transport problems for porous media usually assumes that the Darcy flow velocities are steady. In certain practical situations, the flow velocity can exhibit time‐dependency, either due to the transient character of the flow process or time dependency in the boundary conditions associated with potential flow. In this paper, we consider certain one‐ and three‐dimensional problems of the advective transport of a chemical species in a fluid‐saturated porous region. In particular, the advective flow velocity is governed by the piezo‐conduction equation that takes into account the compressibilities of the pore fluid and the porous skeleton. Time‐ and/or mesh‐refining adaptive schemes used in the computational modelling are developed on the basis of a Fourier analysis, which can lead to accurate and optimal solutions for the advective transport problem with time‐ and space‐dependent advective flow velocity distributions. Copyright © 2006 John Wiley & Sons, Ltd.     

Simultaneous optimization of the performance of flotation circuits and their simplification using the jumping gene adaptations of genetic algorithm-II: More complex problems

The binary-coded elitist non-dominated sorting genetic algorithm with the modified jumping gene operator (NSGA-II-mJG) is used to obtain global optimal solutions of flotation circuits. Several single-objective and multi-objective optimization problems are solved using the interconnecting cell linkage parameters (fraction flow rates) and the mean cell residence times as the decision variables. In the single-objective problem, the overall recovery of the concentrate stream is maximized for a desired grade of the concentrate. Two two-objective optimization problems are then solved. In one, the number of non-linking streams and the overall recovery of the concentrate are maximized simultaneously. This gives several simple circuits in a systematic manner with only marginally lower recoveries. In the other two-objective optimization problem, the overall recovery of the concentrate is maximized while the total cell volume is minimized. A three-objective problem (maximization of the overall recovery of the concentrate, maximization of the number of non-linking streams and minimization of the total cell volume) is then solved. All the problems constrain the grade of the product to lie at a fixed value. Finally, a complex and computationally intensive four-objective optimization problem is solved. The solution of several practical optimization problems in this study helps develop useful insights into the optimal solutions.     

Numerical modeling of Forchheimer flow to a pumping well in a confined aquifer using the strong-form mesh-free method

A numerical analysis of non-Darcian flow to a pumping well in a confined aquifer using the strong-form mesh-free (MFREE) method is described. This technique is targeted at problems that use advanced numerical approaches for modeling non-Darcian flow and it supports the assumption that the non-Darcian flow follows the Forchheimer equation. Interpolation functions including the multi-quadrics (MQ) basis function (containing shape factors q and α) and the Gaussian (EXP) basis function (with shape factor ω) were found to be important defining parameters which had significant influence on the numerical results. A series of numerical experiments revealed that when q?=?2 and α?=?0.1, the mesh-free method yielded good results and the range of 10^?6?–?10^?3 might be a good choice for the shape factor ω in the EXP basis function. A comparison between the strong-form MFREE method and the finite difference method was done; the results showed that the strong-form MFREE method was very effective for solving non-Darcian flow near a pumping well in a confined aquifer, and was favorable over the finite-difference method, which could undergo oscillation and converging problems at early times.