油气成藏流体动力系统分析原理及应用

阐述了油气成藏流体动力系统分析的基本原理,把油气成藏流体动力系统分为重力驱动型、压实驱动型、滞流型和封存型四种类型。结合国内外的研究实例,分析了不同类型流体动力系统油气藏形成和分布的规律,强调在不同类型的流体动力系统中,油气藏形成的机理不同,在成藏动力学研究中有不同的侧重点。加强重力驱动型和封存型流体动力系统动力系统油气成藏条件研究对我国南方海相盆地和其它勘探程度较高的盆地深部的油气勘探具有重要意义。     

超压盆地中泥岩的流体压裂与幕式排烃作用

流体压裂是在异常高流体压力体系的低渗泥岩中流体活动的主要输导通道。流体压裂不仅导致低渗泥岩的幕式压实作用,而且为油气运移,储集的研究提供了新的理论模式。超压盆地泥岩的压实演化可划分为两个阶段,即连续压实和幕式压实阶段,其中幕式压实阶段又可根据导致流体压裂的主控因素进一步划分为两个亚阶段,即水力压裂和生烃压裂,前者主要由于泥岩欠压实和新生流体源的增压所致,后者则主要由于泥岩中有机质生烃及烃类裂解后增     

京西矿震活动特征及其与天然地震关系初探

该文介绍了门头沟矿震的概况;对门头沟矿震与天然地震进行了相关分析,认为门头沟煤矿矿震活动可作为一种较好的监视首都圈中西部强震的中尺度监测手段;论证了门头沟煤矿矿震活动作为首都圈地应力变化监测哨的地质依据,并初步建立了矿震作为地震前兆的力学模型;提供了矿震预测天然地震的地质依据。     

Multiscale approach to geo‐composite cellular structures subjected to rock impacts

Geo‐composite cellular structures are an efficient technological solution for various applications in civil engineering. This type of structure is particularly well adapted to resisting rockfalls and can act as a defensive structure. However, the design of such structures is for the most part empirically based; this lack of research‐based design stagnates optimization and advanced development. In this paper, the mechanical behaviour of a geo‐composite cellular structure is investigated using a multi‐scale approach, from the individual cell made up of an assembly of rocky particles contained in a wire netting cage to the entire structure composed of a regular array of cells. Based on discrete modelling of both the cell and structure scales, a computational tool has been developed for design purposes. Copyright © 2007 John Wiley & Sons, Ltd.     

Accelerating the convergence of coupled geomechanical‐reservoir simulations

The pressure variations during the production of petroleum reservoir induce stress changes in and around the reservoir. Such changes of the stress state can induce marked deformation of geological structures for stress sensitive reservoirs as chalk or unconsolidated sand reservoirs. The compaction of those reservoirs during depletion affects the pressure field and so the reservoir productivity. Therefore, the evaluation of the geomechanical effects requires to solve in a coupling way the geomechanical problem and the reservoir multiphase fluid flow problem. In this paper, we formulate the coupled geomechanical‐reservoir problem as a non‐linear fixed point problem and improve the resolution of the coupling problem by comparing in terms of robustness and convergence different algorithms. We study two accelerated algorithms which are much more robust and faster than the conventional staggered algorithm and we conclude that they should be used for the iterative resolution of coupled reservoir‐geomechanical problem. Copyright © 2006 John Wiley & Sons, Ltd.     

An elastoplastic strainhardening model for soil allowing for hydraulic bonding–debonding effects

The paper presents a strainhardening constitutive model for unsaturated soil behaviour based on energy conjugated stress variables in the framework of superposed continua. The proposed constitutive law deals with hydro‐mechanical coupling phenomena. The main purpose is to develop within a consistent framework a model that can deal with possible mechanical instabilities occurring in partially saturated materials. The loss of capillary effects during wetting processes can, in fact, play a central role in unstable processes. Therefore, it will be shown that the bonding effects due to surface tensions can be described in a mathematical framework similar to that employed for bonded geomaterials to model weathering or diagenesis effects, either mechanically or chemically induced. The results of several simulations of common laboratory tests on partially saturated soil specimens are shown. The calculated behaviour appears to be in good qualitative agreement with that observed in the laboratory. In particular it is shown that volumetric collapse phenomena due to hydraulic debonding effects can be successfully described by the model. Finally, it will be highlighted the ability of the model to naturally capture the transition to a fully saturated condition and to deal with possible mechanical instabilities in the unsaturated regime. Copyright © 2008 John Wiley & Sons, Ltd.     

基于地层信息插值的FLAC3D简易建模方法

为建立一种简易的FLAC3D建模方法,降低FLAC3D前处理时的建模难度,本文基于Python编程语言开发了建模文件生成程序。该程序以岩体各层位的高程信息为基础,采用Kriging插值生成离散网格点数据;并采用离散网格点自动生成建模所需要的网格数据文件;将该文件导入FLAC3D软件中,即可生成与真实钻孔数据和地层信息吻合的三维模型。程序提供了3种FLAC3D内置单元模型可供选择。该方法采用Kriging插值算法,可生成精确的三维地层模型数据。与FLAC3D软件自身的脚本建模语言相比,该方法简单快速。本文使用3类应用数据进行建模,验证提出的插值建模方法可以针对复杂的地形和地质信息生成精确的三维模型。研究成果为采用FLAC3D进行复杂地质区域数值模拟计算提供了一种简单、高效、准确的建模工具。     

强夯碎石土地基土体结构的试验研究

通过现场容重试验和注水试验研究了碎石土地基的密度和渗透性在强夯处理前后的变化,探讨了强夯对土体结构的影响.试验结果表明：强夯能有效改善碎石土的结构,且浅部明显,随深度增加表现出逐渐不明显的趋势;强夯作用下,土体结构的改变在3m以上区域为颗粒填充所致,3m以下则为土体孔隙压缩.     

Advances in studies on concrete durability and countermeasures against freezing-thawing effects

This paper is a meta-analysis of recent domestic and foreign research on freezing-thawing effects on concrete durability. The main theories on the mechanisms of freeze-thaw damage to concrete are introduced： the hydrostatic pressure theory, the osmotic pressure theory, the critical water saturation degree theory, the dual mechanism theory, and the micro-ice-crystal lens model theory. The influence laws of freezing-thawing on the mechanical properties of concrete are summarized, and countermeasures to improve concrete durability in freezing-thawing circumstances are presented. This work provides valuable references for future engineering constructions in cold regions.