Characterizing heterogeneous permeable media with spatial statistics and tracer data using sequential simulated annealing

Characterizing heterogeneous permeable media using flow and transport data typically requires solution of an inverse problem. Such inverse problems are intensive computationally and may involve iterative procedures requiring many forward simulations of the flow and transport problem. Previous attempts have been limited mostly to flow data such as pressure transient (interference) tests using multiple observation wells. This paper discusses an approach to generating stochastic permeability fields conditioned to geologic data in the form of a vertical variogram derived from cores and logs as well as fluid flow and transport data, such as tracer concentration history, by sequential application of simulated annealing (SA). Thus, the method incorporates elements of geostatistics within the framework of inverse modeling. For tracer-transport calculations, we have used a semianalytic transit-time algorithm which is fast, accurate, and free of numerical dispersion. For steady velocity fields, we introduce a transit-time function which demonstrates the relative importance of data from different sources. The approach is illustrated by application to a set of spatial permeability measurements and tracer data from an experiment in the Antolini Sandstone, an eolian outcrop from northern Arizona. The results clearly reveal the importance of tracer data in reproducing the correlated features (channels) of the permeability field and the scale effects of heterogeneity.     

Design of geological data systems for developing nations

For analytical, inventory, and a variety of other basic types of geological data the main functions of an information management system can adequately be accommodated by simple systems in which comprehensiveness is compromised in favor of practicality and ease of implementation. Albeit possessing some shortcomings, such a strategy is likely to prove profitable particularly to geologists in developing nations who are confronted with the task of self-developing much needed geological data systems in the face of limited electronic data processing resources. Based on the experience of the Geological Survey of Israel, several considerations and practical guidelines for the design and implementation of such systems can be outlined. Data bases should be limited in their scope to specific subjects or projects, be designed to serve existing and only the more realistic foreseeable needs, and include provisions for merger and intelligent communication with related files. Such data bases typically contain logically simple-structured information and are small in size. Revision, deletion, and update transactions are infrequent; the search criteria for retrieval are for the most part predictable and a fast response time is not essential. These attributes prescribe a preference for simple fixed- or semi-free-format sequential files which, in turn, simplify appreciably the programming of the supporting software. Input forms should be meticulously planned with due consideration given to aspects of software compatibility, user convenience and acceptance, and efficiency in data gathering. The use of standard forms should be integrated into the institution's routine to facilitate direct data entry by each contributor, thereby improving and economizing the data collection process, and to secure data capture at its acquisition level (field, laboratory). The user's more immediate retrieval needs are adequately satisfied by a master list, documenting the entire data base and a number of external inverted index directories cross-referencing the master list according to the attributes by which the file is most likely to be searched. Further development of output capabilities should be directed to provide for flexible retrieval by multikey query functions and base map posting. For data files storing raw chemical analyses of rocks and water samples, the incorporation of processing capabilities to compute interpretative geochemical parameters as an integral part of the system's output is particularly useful. Paper presented at the 25th International Geological Congress, Section 16A, Sydney, Australia, August 1976.     

电磁式多参数钻孔测漏仪的应用研究

介绍了电磁式多参数钻孔测漏仪的构成、数据计算过程及处理原理、仪器的机械结构、测漏工艺流程和野外试验情况。     

Reduction of lithologic-log data to numbers for use in the digital computer

The development of a standardized system for conveniently coding lithologic-log data for use in the digital computer has long been needed. The technique suggested involves a reduction of the original written alphanumeric log to a numeric log by use of computer programs. This numeric log can then be retrieved as a written log, interrogated for pertinent information, or analyzed statistically.publication authorized by Director, U.S. Geological Survey.     

B-splines for smoothing and differentiating data sequences

Sequence convolution formulae, based on the B-splines of I. J. Schoenberg provide simple and effective methods for smoothing and differentiating data sequences. Their time and frequency domain properties allow calculation of the degree of smoothing and noise rejection, and their z-transforms lead to the rapid calculation of formulae from a simple sequence of polynomials. As an example of their use, numerical differentiation is used to produce smooth velocity—depth profiles and to delineate major velocity discontinuities from time—depth data logged at a well.     

复杂区宽线地震资料处理技术及应用

宽线地震采集原始数据相比二维数据具有更丰富的信息。为充分挖掘宽线数据本身的优势和潜力,提升宽线数据处理效果,本文根据宽线数据和二维及三维数据的异同,借鉴了目前"两宽一高"三维地震数据处理流程,主要研究了宽线有源噪音压制及浅海拖缆宽线大羽角数据共中心点离散处理技术,提出了观测系统定义方式需要根据不同处理模块的要求进行实时变换的建议,总结完善了针对复杂区宽线处理技术策略,提升了宽线的处理成果剖面质量,为复杂区宽线地震资料处理总结了一些经验。     

区域重力调查资料整理及数据处理

区域重力调查资料整理及数据处理,主要是外业数据采集,按"五统一"计算布格异常值,通过数据处理,将布格异常进行网格化、异常圆滑、异常解析延拓、异常分量转换、异常导数计算,求取异常体埋深,最后实现成果图件。本文通过几年的工作总结,将各种整理计算公式编写出来,为今后工作提供参考。     

利用地震P波确定煤层瓦斯富集带的分布

查明煤层瓦斯富集区域,对可能的瓦斯突出点进行预报,是当前煤矿生产中亟待解决的重要课题。利用地震P波对裂缝性地层所表现出的方位各向异性特征,根据地震属性随方位角变化可以预测裂隙发育方向和密度的基本原理,应用多种地震P波方位属性预测裂隙发育带。通过对淮南张集煤矿西三采区三维地震P波资料的处理,获得6个方位地震数据体,从中提取多种与煤层和围岩裂隙相关的地震属性,并计算出裂隙的发育方向和密度,为确定瓦斯富集带的分布提供了一种新的途径。     

几种重排算法在地震信号处理中的实验分析

阐述了时频分析技术中重排算法的基本思想,给出了部分重排算法的局部能量重心表达式;设计了两个数值实验,利用几种重排算法对单道地震信号进行了计算和分析比较。结果表明：重排算法不仅能有效抑制交叉项,同时也能提高时频聚集性,从而获得更理想的局部信号特征。其中以重排Spectrogram分布的时频聚集能力最佳,尤其适合于突出主频信号;重排平滑伪Wigner-Ville分布同样也能够获得较理想的时频效果,但稍弱于前一种方法;重排伪MH分布的时频聚集性相对较差,没有对分散的能量进行有效的重新分配处理。重排算法因其突出的时频聚集能力,应用在地震剖面中可以得到更加细致的瞬时频率特征。     

地震资料的多准则速度分析方法

速度分析是地震数据处理中至关重要的一环,常规速度分析方法中,给定一系列相同间隔的速度进行扫描,以叠加能量或相似系数等作为速度分析的准则制作速度谱.速度谱的能量团通常在正确的动校正速度附近存在一定的发散,从而影响速度的拾取.通过对方差为准则的速度分析方法进行分析和研究,认为方差对同相轴的相干性比较敏感,因此,方差速度谱具有较高的精度.拾取方差速度谱中最小方差数值对应的扫描速度为动校正速度,然而实际资料处理时,由于精度太高,最小方差数值对应的区域太小,不利于速度的拾取.为此笔者提出了以方差倒数、叠加能量和相似系数三者的乘积为目标函数的多准则速度分析方法.噪声会对方差产生影响,然而噪声只是提高方差的整体数值,不会改变方差的相对大小关系,因此地震数据含有一定噪声时本文方法仍然适用.通过模型数据和实际资料的处理,验证了本方法的正确性和实用性.     

数据预处理技术在地学大数据中应用

大数据时代随着数据的爆发式增长,在带来可供研究的海量数据的同时,也带来巨量的噪声和冗余数据。在地学领域,由于研究方向和技术方法手段的多样化,产生了数据量巨大和类型众多的地学数据集合。在地学信息的研究过程中,经常碰到地学信息孤岛,分图幅地学数据边界系统误差和地学文档的非结构化问题。在对地学数据进行信息的提取和挖掘之前,必须根据研究目的对地学大数据进行预处理,使冗余、复杂的大数据转为结构化、准确、可用的数据。本文以地学大数据的预处理技术为切入点,从地学数据交互标准与语义、数据调平、地质图接边和文本结构化等四个研究方面,分析阐述目前地学大数据挖掘方面存在的问题及主要的解决手段,同时也对多元数据融合在大数据中的应用进行了阐述。希望通过本文对地学大数据预处理技术的探讨,能对地学大数据的挖掘有所帮助。     

大数据背景下地质云的构建与应用

地质学属于数据密集型科学,并与地球科学面临的问题息息相关。已经收集的和将要收集的大量数字国土相关数据,由于科学研究的需要,正在不断加以检验和扩充。大数据时代背景下,中国国土资源数字化、信息化的战略行动具有深远意义,大数据的相关技术应用为实现地质工作的现代化和信息化提供了有效的支撑。重点介绍大数据背景下的"地质云"构建理念与方法,以及大数据在地学领域的应用。大数据为非结构化、半结构化的地质数据带来了新的处理方法与理念。地质云的构建旨在探索以需求带动的地质核心数据的应用,挖掘非结构化数据的新数据信息,以支撑国土资源管理决策。     

A least-squares method for determining the best-fit point maximum, great circle, and small circle to nondirectional orientation data

Given a set of nondirectional orientation data (fold axes, lineations, dip and dip direction of bedding, universal stage readings of crystallographic axes, etc.),the best-fit line (point maximum),plane (great circle),or cone (small circle)can be determined by minimizing the sum of the squares of the angular residuals using a simplex convergence technique. Stereoplots of the angular deviation over the complete lower hemisphere for these distributions may also be generated when consideration of the constraint on the best-fit position is important; for example in comparing different data sets of the same structural element. The routines are available as a FORTRAN coded computer program.     

大数据背景下地质云的构建与应用

地质学属于数据密集型科学,并与地球科学面临的问题息息相关。已经收集的和将要收集的大量数字国土相关数据,由于科学研究的需要,正在不断加以检验和扩充。大数据时代背景下,中国国土资源数字化、信息化的战略行动具有深远意义,大数据的相关技术应用为实现地质工作的现代化和信息化提供了有效的支撑。重点介绍大数据背景下的“地质云”构建理念与方法,以及大数据在地学领域的应用。大数据为非结构化、半结构化的地质数据带来了新的处理方法与理念。地质云的构建旨在探索以需求带动的地质核心数据的应用,挖掘非结构化数据的新数据信息,以支撑国土资源管理决策。     

Inversion of GDS data of northwest Himalaya using EM2INV

This paper reviews the validity of earlier models obtained after quantitative interpretation of GDS data and presents a fresh model using the inversion scheme EM2INV. The 2-D inversion of data is more objective than the earlier interpretation performed by using trial and error method. The inversion results indicate that the present model differs from the earlier ones. The reason could be that available GDS data are sufficient only for deriving the horizontal variation of subsurface resistivity. In order to study the vertical resistivity variation additional MT sounding data would be required. It would therefore be desirable to carry out MT survey in the specified area. A more comprehensive/appropriate model could be derived from joint inversion of GDS and MT data.     

An enhanced ensemble Kalman filter scheme incorporating model error in sequential coupling between flow and geomechanics

In this work, we construct a new methodology for enhancing the predictive accuracy of sequential methods for coupling flow and geomechanics while preserving low computational cost. The new computational approach is developed within the framework of the fixed-stress split algorithm procedure in conjunction with data assimilation based on the ensemble Kalman filter (EnKF). In this context, we identify the high-fidelity model with the two-way formulation where additional source term appears in the flow equation containing the time derivative of total mean stress. The iterative scheme is then interlaced with data assimilation steps, which also incorporate the modeling error inherent to the EnKF framework. Such a procedure gives rise to an “enhanced one-way formulation,” exhibiting substantial improvement in accuracy compared with the classical one-way method. The governing equations are discretized by mixed finite elements, and numerical simulation of a 2D slab problem between injection and production wells illustrate the tremendous achievement of the method proposed herein.     

遥感数据及航放、航磁数据处理浅析

以某区遥感数据、航放数据和航磁数据处理为例,阐述了遥感数据处理的基本思路、波谱特征分析及采用的处理方法;探索了遥感数据与航放数据、航磁数据融合的处理方法;分析了其处理成果的地质意义。它不仅对研究区地质环境研究及铀矿找矿具有一定意义,而且对其他地区的应用也有参考价值。     

高精度静态GPS数据处理分析

随着GPS定位技术的广泛应用,GPS测量在工程测量中的地位日益重要。GPS数据处理技术与方法也在不断进步,因而高精度GPS数据处理方法研究也越来越受到关注。本文结合理论基础,从一定层面上,阐述了高精度GPS数据处理方法的重要性和可靠性,技术的革新和改进更是决定其主导地位的重要因素。也在关注相应技术发展趋势的同时,对该项技术在今后的研究和应用中所面临的趋势做了展望。     

地质数据处理中通用软件的应用

通用软件MicrosoftExcel具有公式输入计算、数据库排序、筛选、数据分析及图表制作等多种功能 ,将其用于地质数据计算、制表和统计分析 ,对提高区调工作效率和质量很有实效且易于推广。本文以实例简介其使用效果及方法。     

Petroleum resource data systems

Construction of a petroleum data file first requires answers to specific questions: Who are to be the users; for what purpose is the file to be used; what are to be the data sources; are proprietary data to be included; is graphic display of the data desired? After fixing these guidelines, attention may be directed to data acquisition and file building. Because many useful software systems are now readily available, this aspect of the file-building process should require little attention. In general, the software should include an open-ended format to permit addition of new data items and easy updating, with economy of space on the tape or lisc. With respect to the data, and unless the file has a narrow usage, all available data on the geological and engineering aspects of petroleum occurrence should be collected. Proprietary data should be avoided, if possible, or else clearly labeled, and the file should be planned for public use, for convenience, to provide a needed service, and to avoid the pitfalls of implied secrecy.This paper was presented at the International Geological Correlation Program (IGCP) Project 98 entitled Standards for Computer Applications in Resource Studies held at Loen, Norway, September 27–October 1, 1976.