油层出砂预测模型研究

分析了裸眼完成井和射孔完成井的油层出砂机理 ,以线弹性理论为基础 ,同时考虑垂直井眼围岩应力场对射孔孔道稳定性的影响 ,建立了一种新的射孔完井临界出砂模型 ,并编制了出砂预测系统的设计软件。在辽河油田现场应用的实例表明 ,该模型的预测结果与现场工程实践中已有的油井出砂经验预测模型相吻合。     

高含水期射孔井出砂预测模型的建立及应用

对取心井测井数据和岩心三轴试验岩石强度数据进行了分析，得到了油层砂岩强度与声波时差和井深的回归关系式，这一关系式可用于胜坨油田及其周边油区岩石强度的计算。以岩石破坏准则为基础，运用岩石力学理论和分析方法，考虑到射孔孔眼周围岩石应力场对孔道稳定性的影响，建立了射孔完井临界出砂预测模型。预测结果表明，油层砂岩岩石强度是影响油井出砂的重要因素；弱胶结岩石在较低的流速下会有出砂现象，而胶结强度高的砂岩在较高的流速下也不容易出砂。胜坨油田高含水期出砂与含水量上升有密切关系，这主要是因为含水量上升破坏了产层胶结结构，降低了岩石强度。利用孔道出砂预测模型进行计算，得到了预防出砂的临界生产压差和临界产量。该模型预测的结果可用于：①判断新井投产、老井补孔等新投产层位的出砂，并根据预测结果确定合理的防砂措施，优化生产参数；②判断目前生产层位出砂状况，确定多层生产井的出砂层位，调整生产参数及控制地层出砂程度。对胜坨油田3个不同区块的生产井进行了计算，其计算结果对该油田高含水期开发方案的设计有指导作用。目前该方法已在胜坨油田现场应用122井次，出砂预测的准确率大于82％。     

“胜坨油田特高含水期地层出砂规律及防砂治砂技术研究”通过鉴定

由石油大学(华东 )博士生导师李兆敏教授主持完成的“胜坨油田特高含水期地层出砂规律及防砂治砂技术研究”近日通过了由山东省科技厅组织的专家鉴定。鉴定委员会一致认为该项研究成果达到了国际先进水平。科研人员针对弱胶结砂岩高含水开发期储层易出砂并且严重影响生产的实际情况 ,对胜坨油田特高含水期地层出砂规律预测进行了研究 ,建立了球形、圆柱形两种方式的射孔孔道模型 ;应用岩石破坏准则研究了井眼围岩应力场对射孔孔道稳定性的影响 ,确定了射孔完井方式下油井出砂的临界生产压差和临界产量 ;对胜坨油田 1 9块岩样试验 ,得到了岩…     

出砂井射孔套管变形分析及射孔参数优化

针对出砂井因上覆地层沉降与射孔段地层空洞而导致的射孔套管变形问题,采用有限元分析软件,建立考虑上覆地层位移与出砂空洞的射孔套管变形分析模型,采用经典Lame公式验证模型的正确性,分析射孔孔眼密度、孔径和射孔相位角对射孔套管变形的影响.结果表明:出砂井射孔套管在轴向载荷作用下的变形不同于在径向挤压作用下的变形,微小的上覆...     

高含水期射孔井出砂预测模型的建立及应用

对取心井测井数据和岩心三轴试验岩石强度数据进行了分析 ,得到了油层砂岩强度与声波时差和井深的回归关系式 ,这一关系式可用于胜坨油田及其周边油区岩石强度的计算。以岩石破坏准则为基础 ,运用岩石力学理论和分析方法 ,考虑到射孔孔眼周围岩石应力场对孔道稳定性的影响 ,建立了射孔完井临界出砂预测模型。预测结果表明 ,油层砂岩岩石强度是影响油井出砂的重要因素 ;弱胶结岩石在较低的流速下会有出砂现象 ,而胶结强度高的砂岩在较高的流速下也不容易出砂。胜坨油田高含水期出砂与含水量上升有密切关系 ,这主要是因为含水量上升破坏了产层胶结结构 ,降低了岩石强度。利用孔道出砂预测模型进行计算 ,得到了预防出砂的临界生产压差和临界产量。该模型预测的结果可用于 :①判断新井投产、老井补孔等新投产层位的出砂 ,并根据预测结果确定合理的防砂措施 ,优化生产参数 ;②判断目前生产层位出砂状况 ,确定多层生产井的出砂层位 ,调整生产参数及控制地层出砂程度。对胜坨油田 3个不同区块的生产井进行了计算 ,其计算结果对该油田高含水期开发方案的设计有指导作用。目前该方法已在胜坨油田现场应用 12 2井次 ,出砂预测的准确率大于 82 %。     

防砂井的合理完井方式

防砂工艺和效果与完井方式有密切的关系，提出并分析了四种完井方式．在条件允许的情况下，采用裸眼砾石充填进行先期防砂完井，可以获得较好的油、气流通能力和较厚的砾石层，可下入大直径的滤砂管，这种完井方法有利于防砂．对于用射孔方式完成的井，如果预测有出砂倾向，则应采用大直径套管作为生产套管，以高密度射出大直径的孔．对于胶结差的疏松产层则建议采用渗透性人工井壁完井．     

垂直井砾石充填防砂最小排量的确定方法

将水平管中清水及低粘液体携砂时的临界流速公式用于计算垂直井砾石充填防砂的最小排量，研究了垂直井低粘液体及清水携砂液临界流速计算公式的特点及应用条件，分析了射孔孔眼临界流速及防砂井最小排量的影响因素，并利用现场数据计算了防砂井最小排量。结果表明，射孔孔眼直径及携砂比增加时，临界流速增加；射孔密度、射开厚度、孔眼直径及临界流速增加时，砾石充填最小排量也增加。提出的临界．流速计算方弦可用于现场施工排量的设计，携砂液初始排量接近或高于临界排量是保证防砂成功并获得较长有效期的根本条件。     

防砂井的合理完井方式

防砂工艺和效果与完井方式有密切的关系。提出并分析了四种完井方式。在条件允许的情况下，采用裸眼砾石充填进行先期防砂完井，可以获得较好的油、气流通能力和较厚的砾石层，可下入大直径的滤砂管，这种完井方法有利于防砂，对于用射孔方式完成的井，如果预测有出砂倾向，则应采用大直径套管作为生产套管，以高密度射出大直径的孔。对于胶结差的疏松产层则建议采用渗透生人工井壁完井。     

裸眼完井出砂预测模型研究

油田开采到中后期，疏松砂岩油藏的出砂问题已成为影响油井产能和损害设备的严重问题。为了研究裸眼完井的出砂机理，根据岩石力学及弹塑性力学理论，对直井井壁围岩应力分布进行了分析计算，采用Mohr—Coulom准则及复变函数方法建立了非均匀地应力作用下油井出砂的解析模型。利用该模型和已知的出砂判别准则即可确定油井的出砂现状。在中原油田现场的应用实例表明，该模型预测结果与现场工程实践中已有的油井出砂经验预测模型相吻合。     

套损井防砂工艺技术

针对吐哈油田套损井出砂严重、常规防砂方法无法解决套损井防砂难题,开展了套损出砂高强度筛管防砂技术、裸眼地层深部防砂技术、复合射孔防砂技术研究,形成了比较完整的套损井修复防砂工艺技术,并在现场进行了推广应用,有效地解决了套损井防砂难题。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。