地下水封式液化石油气储藏洞库修建技术

结合汕头地下水封式LPG储库的修建,研究储气库的水压密封原理及LPG洞储的气密条件,并通过渗流场的三维数值模拟,得出储气库周围的压力水头及水力梯度的分布规律,验证气密性条件和设置人工水幕的必要性。由于洞库是裸洞储气,且埋深大、跨度大,因此进行了洞室稳定性的三维数值分析,同时优化施工方案,确保施工及运营过程洞室的稳定性。介绍注浆和水幕钻孔技术,这是地下水封式LPG储库修建的两项关键技术,良好的注浆效果可以减少开挖期间的渗漏水、有利于保持必要的水位线、有利于封闭裂隙而减少气体逃逸,水幕钻孔是运营期间水幕保持良好工作状态的保证。汕头地下水封式LPG储库的修建技术对今后我国地下水封式储气库的设计、施工都有一定的参考价值。     

考虑流固耦合的地下储油洞库稳定性研究

应力场与渗流场耦合是影响水封式地下储油洞库群稳定性的重要因素之一。洞库群的开挖导致形成区域地下水降落漏斗,因此储库水封系统必须保证稳定的地下水位。以“黄岛地下水封洞库工程”的设计方案为模型,基于流固耦合分析理论,采用有限差分软件Flac3D进行数值模拟,主要分析了饱和水状态下,渗流场对洞库周围围岩应力、位移变形和孔隙水压力的影响,并确定合理的水封方案和最优的水封巷道高度。文中所得结论对实际地下洞库群的设计施工具有一定的参考价值。     

水封式地下储气洞库的应用及研究

通过对水封式地下储气洞库应用及发展的描述 ,指出利用地下洞室储存石油液化气LPG(LiquefiedPetroleumGas)是当前乃至将来的大趋势。并对水封式地下储库的基本原理及设计作了较为详细的论述。对我国地下储气工程的修建及理论研究有一定的参考价值。     

地下水封石油洞库渗流场-应力场耦合作用研究综述

石油和天然气储备已经被许多国家提到了战略的高度上,地下水封石油洞库作为原油储备的方式之一在中国已经进入实施阶段。本文通过综述国内外地下水封石油洞库渗流场-应力场耦合作用机理研究的现状、研究实际工程中遇到的问题、主要的研究手段、分析研究可能出现的新的技术趋势、并结合国内外地下水封石油洞库研究的成果,简要提出地下水封石油洞库渗流场-应力场耦合作用机理研究的主要方向是渗流场和应力场耦合情况下的洞库稳定性、围岩岩石力学行为特征和岩石的流变损伤。     

地下水封石油储备库初始渗流场数值反演分析

渗流场分析是地下水封石油储备库设计的重要内容,而合理可靠的渗透系数是准确分析裂隙岩体渗流场的前提。以黄岛地下水封石油储备库工程为背景,对库区初始渗流场进行反演分析。首先,采用离散元3DEC软件直接生成尺寸分别为5 m×5 m,10 m×10 m,15 m×15 m,20 m×20 m,25 m×25 m,30 m×30 m的三维节理离散网络模型,并给出判别模型与节理相交的条件;基于裂隙介质的渗透张量理论,利用 MATLAB计算不同尺寸的裂隙岩体渗透张量,并确定了库区裂隙岩体表征体单元(REV)的大小,并结合库区现场试验实测数据,对节理裂隙岩体的渗透张量进行校核;最后,采用COMSOL Multiphysics软件,在裂隙岩体渗透系数各向异性条件下,反演库区的初始渗流场。研究成果为地下水封石油储备库水封性评价及稳定性分析提供较合理的初始渗流场条件。     

大连地下石油储备库初始渗流场数值反演

 初始渗流场分析是水封式地下石油储备库设计中的重要内容和先决条件,现场压水试验只能提供较准确的各向同性渗透系数,而不能反映各向异性的渗透特征。结合大连地下石油储备库工程,提出一种基于随机节理网络模拟技术反演岩体各向异性渗透特征的方法。首先,采用三维离散元程序3DEC内置的Fish语言,直接生成不同尺寸的三维节理网络模型,通过推导的判别式来统计模型中各组节理的个数及产状信息。其次,利用裂隙介质的渗透张量理论计算不同尺寸的岩体渗透张量,进而确定节理岩体的表征体元(REV)。根据现场压水试验实测资料,修正节理岩体的渗透张量,再利用Matlab软件计算渗透主值及渗透特征向量。最后,考虑渗透系数的空间正交各向异性,采用FLAC3D的Fl_anisotropic的渗流模型反演库区的初始渗流场,为水封式地下石油储备库水幕设计及稳定性分析提供较合理的初始渗流场条件。     

加油加气站地下储罐泄漏事故模拟及影响因素分析

利用多相混合数值模拟模型对加油加气站常用石油燃料(汽油、液化石油气)地下储罐不同位置发生泄漏事故在罐池中渗流扩散过程进行模拟,得到汽油、液化石油气(LPG)气相和液相饱和度、危险浓度区域、流速等空间分布规律以及流动趋势变化,并对影响汽油、LPG流动的主要因素进行分析,对比讨论其泄漏渗流扩散的特点。模拟结果表明:在泄漏口周围地下环境条件相同情况下,地下储罐泄漏时汽油渗流扩散比液化石油气渗流扩散缓慢;汽油地下储罐泄漏主要对地下环境造成污染,液化石油气对地下环境造成污染而且给外界环境带来火灾爆炸危险;汽油渗流速度低,整个流场只存在层流,渗流扩散方向主要受重力影响。LPG液相泄漏受重力影响尤为明显;LPG气体渗流扩散方向受出口位置、泄漏速度方向、重力、储罐罐壁形状影响;出口位置是控制气体渗流方向关键因素。     

水封式地下储气洞库的应用及研究

本文通过对水封式地下储气洞库应用及发展的描述 ,指出利用地下洞室储存石油液化气 L PG(Liquefied Petroleum Gas)是当前乃至将来的大趋势。并对水封式地下储库的基本原理及设计作了较为详细的论述。对我国地下储气工程的修建及理论研究有一定的参考价值     

惠州地下水封油库三维非恒定渗流场研究

水封地下油库渗流场的分布是油库区地下水管理和油库运行方案的基本依据之一。为了解惠州水封地下油库区地下水在施工期和运行期的变化情况,应用三维非恒定流数值方法对复杂水文条件下的洞库区渗流场进行模拟,分析了不同初始地下水位条件对洞库区围岩渗流场的影响,探讨了施工期水幕系统不注水条件对油库运行的影响。研究表明:储油主洞开挖期间,水幕系统不注水将导致洞库围岩出现大范围的非饱和区,从而影响洞库多品种油品的储存。运行期水幕注水时的水封效果良好,洞库区围岩在进行灌浆处理后的涌水量较小。     

水封式地下储气洞库的应用及研究

本文通过对水封式地下储气洞库应用发展的描述,指出利用地下洞室储存石油液化气ＬＰＧ（Ｌｉｑｕｅｆｉｅｄ Ｐｅｔｒｏｌｅｕｍ Ｇａｓ）是当前乃至将来的大趋势,并对水封式地下储库的基本原理及设计作了较为详细的论述,对我国地下储气工程的修建及理论研究有一定的参考价值。     

地下水封储气洞库原理及数值模拟分析

 结合我国第一座地下水封储气洞库工程, 对水封式地下储气洞库的原理及设计作了简单的论述。通过数值模拟方法对地下水封储气洞库从理论上进行了分析探讨。为我国地下储气洞库工程的发展、设计和施工提供了理论依据。     

Design and operation problems related to water curtain system for underground water-sealed oil storage caverns

The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China.Although several small underground water-sealed oil storage caverns have been built in China since the 1970 s,there is still a lack of experience for large-volume underground storage in complicated geological conditions.The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns,as well as the long-term stability.Although several large-scale underground oil storage projects are under construction at present in China,the design concepts and construction methods,especially for the water curtain system,are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas.The storage projects currently constructed in China have the specific features such as huge scale,large depth,multiple-level arrangement,high seepage pressure,complicated geological conditions,and high in situ stresses,which are the challenging issues for the stability of the storage caverns.Based on years' experiences obtained from the first large-scale(millions of cubic meters) underground water-sealed oil storage project in China,some design and operation problems related to water curtain system during project construction are discussed.The drawbacks and merits of the water curtain system are also presented.As an example,the conventional concept of "filling joints with water" is widely used in many cases,as a basic concept for the design of the water curtain system,but it is immature.In this paper,the advantages and disadvantages of the conventional concept are pointed out,with respect to the long-term stability as well as the safety of construction of storage caverns.Finally,new concepts and principles for design and construction of the underground water-sealed oil storage caverns are proposed.     

Effectiveness analysis of water-sealing for underground LPG storage

With the developed transient UPNM, numerical simulations are carried out to analyse the seepage field of the underground petroleum storage project in Jingzhou, China. The 3D discrete fracture pipe network model is adopted to systematically analyse the effects of the water curtain system (different water curtain states, water curtain pressure, length and spacing and the angles of the horizontal water curtain system) on the water-sealing effectiveness of the rock caverns in the fractured rock mass in both construction phase and storage phase. Water-sealing performances of different water curtain system schemes with various fracture networks are also discussed. It is found that the effect of the horizontal water curtain is more important than the vertical water curtain. The reducing of the pressure of the water curtain, the length of the water curtain boreholes and the increase of the spacing of the water curtain borehole can deteriorate the seal effect of the water curtain, increase of angles of horizontal water curtain can’t improve water seal. And effective connectivity of fractures is found to be dominant factor to determine water-sealing results. In addition, it is worth mentioning that the fracture network is highly irregular in the flow domain, which greatly influence the seepage field, and the failure of the water seal effect can occur locally. The locally connected unsaturated flow paths have been observed in the study, which cannot be found by using the continuous simulation model. Finally, optimal water curtain system design is recommended. Furthermore, one connectivity evaluation criteria is developed to determine the effectiveness of water-sealing system in the field, according to Lugeon, effectiveness and TEM site test.     

金佛山沥青混凝土心墙坝二维渗流计算分析

渗透水流将会对土石坝的坝体以及坝基渗透破坏产生巨大的危害性。本文依托金佛山水电站工程,根据沥青混凝土心墙堆石坝方案的地质条件及渗流控制特点,建立了平面有限元计算分析模型,模拟了坝体和坝基在不同水位组合条件下的渗流场,重点研究了其渗透破坏的可能性,并且对防渗帷幕和坝基渗透系数的敏感性进行了分析。计算分析结果表明:各种水位组合下,沥青混凝土心墙及防渗帷幕起主要的阻水作用,防渗帷幕的水力比降较大,其安全稳定性需要重视。渗流场分布对防渗帷幕及坝基渗透系数不敏感,而渗流流量相对敏感。     

水布垭地下厂房围岩渗控效应数值模拟与评价

 为减小水布垭地下厂房厂区渗漏并改善厂房围岩的渗透稳定性,工程设计采取防渗帷幕、排水孔幕和排水洞等防渗排水措施。为确保数值计算的稳定性和收敛性,采用Signorini型变分不等式和自适应罚函数相结合的稳定渗流分析方法,对厂房围岩的长期渗控效应进行计算分析;同时,采用基于等效模拟的整体模型分析和基于精细模拟的子模型分析相结合的方法,以减小有限元建模难度并协调计算量和计算精度之间的矛盾。建立评判渗流计算成果合理性的直观准则,即稳定渗流自由面在任意均匀介质内部必连续光滑且不产生回弯,除非自由面穿过渗透性相差悬殊的2种介质之间的界面。结合厂房围岩渗压监测数据,阐明运用上述方法求解含排水孔幕渗流问题的可行性和有效性,论证渗控设计的合理性和进一步优化的可能性。研究成果对类似工程渗控措施的优化设计具有指导意义。     

The anisotropic seepage analysis of water-sealed underground oil storage caverns

The analysis of the seepage field in fractured rock mass is very important to the design of an underground oil storage project and must be done in the primary stage. A novel analytical method to calculate the anisotropic permeability tensor of an initial seepage field is presented in this paper. Fracture network simulation and results of water-pressing injection tests are used for the development of analytical method. As an example, the proposed method is used to model initial and subsequent seepage fields of Dalian water-sealed underground oil storage caverns project. The changes in the seepage field during the construction and operation periods are investigated adequately. The results indicate that this design meets the requirements for the groundwater level and the vertical hydraulic gradient, although their distributions in the two periods are different, the proposed method is acceptable for the anisotropic seepage analysis.