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1.
引入层次分析法,解决大口径油气管道河流穿越的方案选择问题。介绍了层次分析法的基本原理,详细论述了用层次分析法进行大口径油气管道河流穿越方案选择的步骤,以施工周期、河床适应性、施工工艺复杂性、对其它行业的影响、投资为评价因素,构建了最佳河流穿越方案选择的层次结构模型,并应用层次分析法对输气管道唐河穿越方案进行了分析,得出了多个穿越方案对于最佳河流穿越方案的相对权重,最后确定水平定向钻穿越为唐河最佳穿越方案。  相似文献   

2.
该文从河流穿越岩土工程勘察中遇到的问题入手,引入地质雷达技术,并通过工程实例介绍了雷达技术在河流穿越中的应用,通过雷达成果剖面与工程地质钻探剖面的对比分析,体现了雷达技术的应用优势,有效的填补了钻孔间的盲区,弥补了常规岩土勘察技术中的不足,为输油气管道河流穿越勘察增加了一种新方法。  相似文献   

3.
油气管道施工中,沿线多处经过公(铁)路、河流、峡谷、大山等穿(跨)越点,都需要采取特殊的穿(跨)越施工方法。本文就复杂地质条件下定向钻穿越技术在油气管道施工中的应用进行了深入的探讨,提出了自己的建议和看法,具有一定的参考价值。  相似文献   

4.
长输管道是现代油、气资源开发利用的重要基础,其对提高油、气资源的运输安全有着重要的意义。在长输管道设计、建设中,长输管道的河流穿越是设计建设中所面临的重要问题。如何科学利用长输管道河流穿越技术进行长输管道建设是管道设计施工的首要工作。本文从长输管道河流穿越需求分析入手,对长输管道河流穿越技术应用进行了简要论述。  相似文献   

5.
在油气管道工程的施工过程中,油气管道定向钻穿越工程技术要求高、施工风险大,结合我国地域辽阔,地理情况复杂多样的特点,给管道定向钻穿越增加了难度,增大了其定向钻穿越的风险。针对油气管道定向钻穿越过程中存在的施工风险因素,特对定向钻穿越施工前、施工中风险预测、质量控制、穿越质量监管重点、防范等方面作一探讨,为定向钻穿越工程提供宝贵的资料和可借鉴的经验,从而有助于定向钻穿越的顺利完成。  相似文献   

6.
机坪输油管道荷载附加应力分析   总被引:1,自引:1,他引:0  
应用ABAQUS有限元软件,考虑管土相互作用,建立并验证了管道结构有限元分析模型.应用该模型,分析了管周附加应力的分布特征,计算了飞机、施工重型车辆和压路机荷载作用下,管道附加应力及其引起的管道结构应力和变形随管道埋深的变化规律.结果表明:不同管道埋深对应的管周附加应力在管顶至管两侧60°的范围内有显著差异,且该范围内附加应力近似呈抛物线分布.即使管道埋深小至1倍管径时,飞机荷载和施工重型车辆荷载引起的管道结构应力和变形仍远小于容许值,而压路机高振幅振动压应力引起的管道结构应力达到管道强度失效的临界标准,是管道承受的最不利外荷载类型,对管道埋深有重要影响.  相似文献   

7.
人类进入21世纪,能源的全球供求矛盾呈现日益突出的趋势。如何保障我国石油安全有效地供给,已经成为我们面临的巨大挑战。该文针对油气输送管道所受的各种应力的分析,展开了基于应变的油气输送管道的设计讨论。若想对抗各种应力对油气输送管道的损害,需要加强油气输送管道强度和韧性。  相似文献   

8.
目的研究火电厂空冷系统排汽管道应力分布情况,确定用于设计的最不利应力分布模式.方法以火电厂空冷岛为例,采用《钢制压力容器分析设计标准》(JB4732-1995)中计算薄膜应力的方法,考虑将基本载荷、地震荷载及风荷载进行组合,形成各种组合工况,应用ANSYS对某300 MW火电厂空冷岛系统的排汽管道进行大量的仿真分析,并对计算结果进行整理.结果各工况结果中管道应力最大的区域发生在三通,该处一次局部薄膜应力最大值为236 MPa,小于应力限值SⅡ=259 M Pa;除三通外其他区域在各种荷载工况下的最大薄膜应力均较小.其中与-X方向风荷载组合的各计算工况中,管道应力水平比之没有风荷载作用的相对较高,说明风荷载对管道应力影响较大,原因是管道属于高耸结构,且上部结构迎风面积较大.薄膜应力与弯曲应力求和后最大值为280 MPa,该应力为一次应力加二次应力,远小于限值SⅣ=518 M Pa.结论管道应力最大的区域为三通,三通区域的应力水平远高于其他区域,最终得出危险荷载工况作用下管道支座、三通、下部三通、折角以及盖板的应力分布,为300 MW直接空冷排汽管道提供设计依据.  相似文献   

9.
穿越道路管道在长距离输气管道中占有较大比例,而埋设在路面下的管道所承受的主要荷载之一就是车辆荷载,随着经济与交通运输业的迅猛发展,由车辆荷载引起的埋地管道的失效与破坏问题越来越严重.鉴于此,通过选取适当的材料本构关系、接触参数及车辆荷载模型,建立起车辆荷载作用下埋地输气管道的有限元模型并利用数值模拟和算例验证等方法,对车辆荷载作用下埋地输气管道的力学性状进行了分析和模拟.  相似文献   

10.
王振玉  侯红霞 《科技信息》2012,(17):1+14-1,14
本文结合江西天然气管道工程撩河定向钻穿越工程的设计及施工情况,对穿越地段曲线设计、管道壁厚选取、进场道路、卵石层处理、管线回拖等方面的技术难点进行了研究分析,并提出了最优的解决方案,其中定向钻穿越入土角度一般控制在5~20°,出土角度一般控制在4~26°为宜;定向钻穿越河流的曲率半径不小于l500D;计算管道的最小壁厚时,必须考虑管道壁厚计算是在最小屈服极限条件下,管道能够承受同拖力作用的最小壁厚;根据已有的道路合理选择穿越位置时,必须考虑钻机进场的道路;水平定向钻穿越两岸砂卵石层的河流时,建议采用套管隔离卵石层的做法来穿越卵石层,并根据回拖场地情况提出回拖方式。  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

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