Study on the Technology of Supplying Water Safely by Long-Distance Pipeline

The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline. The monitoring, calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable; the hydraulic state transition is smooth when operating conditions change or water supply accidents occur, avoiding the damage of water hammer. This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps of building a mathematics model for the analysis of dynamic hydraulic status.

Criterions and Measures of Route Selection of Shallowly Embedded Long-Distance Oil and Gas Pipeline in Mountain Areas

According to the engineering investigation of long-distance oil and gas pipelines, the criterions and measures of route selection are drawn as follows： the flat landform is the first choice in route alignment. The foot of mountain is the first choice when the route passes by the valley. The route should pass by but the shady and deposited slope and not in sunny and erosive slope as possible as it can. The pipeline should be vertical to contour climbing and descending the mountain except steep slope. Tunnel can be used in crossing foothill. Perpendicularly traversing the river is better than beveling; the worst choice is to put the pipeline along the river. Bypass is the best choice in karsts area. The order of route selection should be pre-choosing, investigation, optimization and adjustment.

THE RISK ASSESSMENT OF THE LONG-DISTANCE OILPIPELINE ENGINEERING

The oilfield construction and long-distance oil pipeline engineering has been developed extensively in China. The risk assessment of oil industry will, however, be an important objective to cope with the development of oil industry , The risk assessment of oil industry has many subjects worthy to be studied.The major purpose of the paper is to research the risk cases of long-distance oil pipeline engineering in Ganshu and Shaanxi provinces.

Water hammer protection for diversion systems in front of pumps in long-distance water supply projects

For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention. In this study, a water hammer protection scheme combined with an overflow surge tank and a regulating valve was developed. A mathematical model of the overflow surge tank was developed, and an analytical formula for the height of the overflow surge tank was derived. Furthermore, a practical water supply project was used to evaluate the feasibility of the combined protection scheme and analyze the sensitivity of valve regulation rules. The results showed that the combined protection scheme effectively reduced the height of the surge tank, lessened the difficulties related to construction, and reduced the necessary financial investment for the project. The two-stage closing rule articulated as fast first and then slow could minimize the overflow volume of the surge tank when the power failure occurred, while the two-stage opening rule articulated as slow first and then fast could be more conducive to the safety of the water supply system when the pump started up.

Cost Minimization of Wireless Sensor Networks with Unlimited-lifetime Energy for Monitoring Oil Pipelines

Cyber-physical-system (CPS) has been widely used in both civil and military applications. Wireless sensor network (WSN) as the part and parcel of CPS faces energy problem because sensors are battery powered, which results in limited lifetime of the network. To address this energy problem, we take advantage of energy harvesting device (EHD) and study how to indefinitely prolong oil pipeline monitoring network lifetime by reasonable selecting EHD. Firstly, we propose a general strategy worst case-energy balance strategy (WC-EBS), which defines worst case energy consumption (WCEC) as the maximum energy sensor node could expend for oil pipeline monitoring WSN. When the energy collected by EHD is equal or greater than WCEC, network can have an unlimited lifetime. However, energy harvesting rate is proportional to the price of EHD, WC-EBS will cause high network cost. To reduce network cost, we present two optimization strategies, optimization workloadenergy balance strategy (OW-EBS ) and optimization first nodeenergy balance strategy (OF-EBS). The main idea of OW-EBS is to cut down WCEC by reducing critical node transmission workload; OF-EBS confirms critical node by optimizing each sensor node transmission range, then we get the optimal energy harvesting rate in OF-EBS. The experimental results demonstrate that OF-EBS can indefinitely extend network lifetime with lower cost than WC-EBS and OW-EBS, and energy harvesting rate P in each strategy satisfies POF-EBS ≤POW-EBS ≤PWC-EBS. © 2014 Chinese Association of Automation.

Development of pipeline steel at Baosteel over the last 20 years

This study reviews the development of Baosteel＇ s pipeline steel over the last 20 years. Energy demand accelerates the development of high-grade pipeline steel as well as modem petroleum and natural gas pipeline construction. Pipeline steel is a kind of typical modem microalloyed steel produced via thermo-mechanical controlled processing. The development process of pipeline steel at Baosteel represents the course of the technological progress of pipeline steel in China. In the last two decades, Baosteel＇ s pipeline steel has been developed from a single product of hot- rolled strips to a variety of products including hot-rolled strips, heavy plates, high-frequency electric resistance welded （HFW） pipes and U-ing-O-ing-Expanding （UOE） welded pipes. Moreover, the proportion of the HFW and the UOE welded pipes has been increasing year by year. UOE longitudinal submerged arc welding （SAW） pipes have become the leading product of strategic significance in Baosteel＇ s pipeline steel family. Over the last 20 years, Baosteel＇ s pipeline steel products have shifted from ＂ferrite ＋ pearlite＂ X52 to ＂acicular ferrite＂ XT0 and X80, and Baosteel has developed hydrogen-induced cracking （HIC） resistant pipeline steel. Baosteel＇ s pipeline steel products have been applied in variety of geographical areas,including deserts, Gobi, mountains,plains as well as the ocean. And both the X100 and the X120 ultra high strength pipeline steels have been produced on a trial basis. Baosteel has accumulatively produced 6.5 Mt of pipeline steel for both domestic and overseas projects. Baosteel will continue strengthening its strategic cooperation with oil companies, and conducting research on ultra high strength pipeline steel, pipeline steel for strain-based design and submarine pipeline steel,etc. , so as to meet the need of construction in the future.

Use of Corrosion Inhibitor in Solid Form to Prevent Internal Corrosion of Pipelines and Acidification Process

Use of corrosion inhibitors in solid form promotes the development of a new technique for internal corrosion protection of oil & gas pipelines and operations of oil wells acidification, because the controlled dissolution of the corrosion inhibitor forms a surface on metallic parts, a protective film that prevents or minimizes undesirable reactions to corrosion. In addition, this technique has important social and environmental benefits, ensures the operator has a lower risk of contamination when handling the product, changes the type of industrial packing, facilitates transportation, reduces solvent use and consequently reduces the waste that normally results from the use of inhibitors. The purpose of this article is to present a class of solid corrosion inhibitor tested in the laboratory and offer proposals for its application in industrial pipes such as gas and oil pipelines.

The CMEKF Method for Sub-Sea Pipeline Monitoring and Leak Detection

A practical approach is discussed for sub-sea pipeline monitoring and leak detection based on the real time transient model . The characteristic method of transient simulation is coupled with the Extended Kalman Filter to estimate the system state where the only observed data are inlet and outlet flow rate and pressure. Because EKF has a time variant track under the non-stationary stochastic process with additive Gaussian noise, the high sensitivity of RTTM to non-stationary operating condition is reduced. A leak location recursion estimation formula is presented based on the real time observed data. The results of 27 groups of test data indicate that the procedure presented is sensitive to a wide range of detectable leak sizes and has a low average relative error of leak location .

潮汐冲刷下悬空管道极限悬空长度的数值模拟研究

滩海地区的输油管道在常年潮汐冲刷作用下,部分管段周围土体被潮汐搬运形成悬空状态,悬空管段在潮汐的周期性冲刷下极易产生变形断裂,对管道运行安全和维护造成了严重影响。针对上述情况,首先对悬空管道进行应力分析,建立悬空管道静力学分析物理模型,进而根据现场调研选取2种不同管材,4种不同管径的悬空管道为实验对象,共8组,运用Comsol软件对8组悬空管道进行不同悬空长度下的应力应变数值模拟研究,通过与2种不同管材的屈服极限对比,最终得到了8组悬空管道的极限悬空长度,并用Origin Lab软件对悬空长度和应力关系进行了拟合,证实了悬空长度与应力呈线性正相关。实验结论可对类似的现场工况提供理论依据,对悬空管道的检查和维护起到一定的指导作用。

石油对杀菌剂THPS耐受条件下微生物腐蚀的影响

杀菌剂是海洋油气开采行业防治微生物腐蚀(Microbiologically influenced corrosion,MIC)的常用方法。然而,杀菌剂可能导致微生物腐蚀行为发生改变,同时石油的存在也会对杀菌剂的使用效果造成一定的影响。通过细胞计数、腐蚀失重、表面分析和电化学分析等方法,研究了石油存在下杀菌剂四羟甲基硫酸磷(Tetrakis(hydroxymethyl)phosphonium sulfate,THPS)对硫酸盐还原菌Desulfobaculum bizertense(简称D.bizertensis)腐蚀行为的影响。结果表明,THPS虽然可以抑制D.bizertensis的生长,但会加剧D.bizertensis对X70管线钢的腐蚀。同时石油的加入,使腐蚀电位进一步升高,表明即便添加了杀菌剂,石油仍会促进D.bizertensis对X70的腐蚀。该结果为海洋含油环境中杀菌剂的合理使用提供了参考。

穿坡油气管道的框架桩防护结构分析方法

针对沿山坡走向铺设的埋地油气管道存在的抗震防护问题,提出了一种新型的框架型抗滑桩式管道防护结构。在采用拟静力法确定作用于结构地震滑坡推力的基础上,将位于滑面以上的结构受荷段作为底端固定的平面框架结构,采用超静定平面刚架结构模型分析;而位于滑面以下的嵌固段则为埋置于稳定地层的两单桩结构,采用侧向受荷的弹性地基梁模型分析,由此建立了框架型抗滑桩的内力及位移计算方法。实例分析表明:框架桩前、后桩及上、下横梁弯矩与剪力的理论计算值与数值模拟结果误差均在±20%以内,理论结果偏于保守;水平地震影响系数对结构内力影响显著,结构内力最大值随水平地震影响系数增加近似呈线性增大,而竖向地震影响系数影响较弱;结构最大内力与土体重度呈线性正相关性,与黏聚力和内摩擦角呈非线性负相关性,且随着土体抗剪强度参数的增大,前、后桩以及上、下横梁的内力分别趋于接近;前、后排桩与上、下横梁的最大内力分别与桩体抗弯刚度呈非线性正相关性与负相关性,而分别与桩体嵌固深度近似呈线性正相关性与负相关性;框架桩间距对结构内力影响显著,而前后桩排间距则对结构内力影响较小。

考虑结构面蠕变特征的隧道围岩长期变形研究

在断层破碎带发育地区,岩石结构面蠕变变形影响着隧道运营安全。首先推导了岩石结构面西原蠕变模型有限差分格式;然后基于FLAC3D的Interface单元,采用自定义本构模型的接口,编写西原蠕变模型的动态链接库,实现了隧道围岩结构面蠕变变形数值模拟;接着开展了岩石单节理面蠕变变形验证模拟;最后结合宜昌成品油管道翻坝项目七里村1号隧道工程,利用新开发模型模拟了运营1、5、10、20 a后的隧道围岩长期变形行为。结果表明:(1)新开发模型预测的隧道围岩蠕变变形与解析解是一致的,最大误差小于2%;(2)隧道围岩蠕变变形数值计算结果与现场监测值之间的偏差较小,证明了蠕变模型的可靠性;(3)隧道开挖后,围岩变形较大,随着时间的推移逐渐减小,1 a后位移趋于稳定;(4)隧道运营1~10 a内无明显破坏,运营20 a后出现了集中于拱脚部位的破坏区,且拱脚处应力集中,因此应加强对拱脚的初期支护;(5)低强度和弱膨胀性特征的泥钙质砾岩使得隧道开挖变形较大,在上方断层长期蠕变作用下,隧道拱顶持续向下变形,造成隧道变形较大。

灰色关联法的输油管道泄漏河流污染影响评价方法研究

为提高输油管道泄露河流污染影响评估的准确性,提出灰色关联法的输油管道泄露河流污染影响评价方法。该方法采用GMS中的MODFLOW模拟河流中溢油扩散情况,引入灰色关联法,结合溢油扩散情况,通过贴近度优化该算法后评价河流污染影响,获得河流水质等级,实现输油管道泄漏河流污染影响评价。应用结果表明,断面2和断面5的水质污染等级分别为III和IV,剩余断面的水质污染等级为II,该评价结果与实际结果一致,表明该方法可准确完成输油管道泄露河流污染的影响评价,具备了一定的评价准确性。

油田管道防腐层检测技术及管道维护探讨

石油企业施工建设过程中,石油管道是重要的传输途径,通常情况下石油管道都埋藏在地下,长时间的使用之后,会受到自然因素的影响,造成管道防腐层的损坏,引发石油资源泄露,给石油企业造成一定的经济损失,同时原油一旦流入土壤、湖泊等环境中,对生态环境也会产生影响,因此我们要高度重视油田管道的防腐检测技术,保障油田管道防腐层防腐性能良好,提高油田管道运输的安全性、稳定性。防腐层的维修和养护是油田管道管理工作中的重点,直接印象油田管道的使用寿命,因此我们一定定期对油田管道防腐层开展检测工作,及时发现油田管道防腐层可能存在的破损,并对破损位置及时修补。根据油田管道防腐层的实际情况,制定科学合理的油田管道维修措施,充分的发挥出油田管道防腐层的作用和价值,促进油田企业的可持续发展。

三维激光扫描应用在油气管道变形测量

油气管道变形测量是为了保障油气管道建设与运维全寿命周期中工程安全极其重要的一个技术环节。为了获取高精度、全方位、完整的油气管道三维数据,采用三维激光扫描技术,解决了常规测量未能全覆盖被测实体的问题。把油气管道物体表面的三维坐标数据进行分析和对比,真实反映所测物体的变形情况。本文依据油气管道变形测量项目,结合三维激光扫描技术的生产过程,分析该技术的全面性、可靠性和优势性。

原油管道泄漏检测与定位

本文设计了一套原油管道泄漏监测系统，首次提出了采用结构模式识别分析管道负压波检测管道泄漏的方法。

基于瞬态模型的油气管道泄漏检测

油气输送管道泄漏是妨碍管道安全运行的主要因素之一。为此,研究了一种新型的基于瞬态模型的管道泄漏检测方法,并对传统的特征线法差分格式进行了改进,将其应用于对管道瞬态模型的求解。该方法利用所采集到的管道前后两端的压力、温度、流量等参数,对管道实施由前到后和由后到前的两次仿真,进而对两次仿真的结果进行比较,从而判断管道是否发生了泄漏,并确定泄漏位置。求解结果表明:该方法不仅大大减少了仿真过程中由启动到稳定所经历的时间,提高了仿真系统的适应性,而且求解速度快,同时还能够满足实时仿真的要求,能够对管道的泄漏做出及时准确的报警,定位误差在被测管长的1%以内,可满足工程应用的要求。

油气储运理论与技术进展

经过60年的发展,中国石油大学油气储运工程学科形成了油气长距离管道输送、多相管流与油气集输、油气储运设施安全与施工等特色鲜明的优势研究方向。近10多年来,伴随着中国油气储运行业的空前大发展以及随之而来的一系列技术挑战,本学科在这些研究领域开展了较系统深入的研究,在易凝高黏原油流变性与管道输送、天然气及成品油管道输送、油气水多相流动、油气水分离、多相混输系统流动保障、流动减阻机制、油气管道与集输系统节能、管道强度设计与安全评价、油气储运设施完整性管理、油气管道与地下储库施工等方面取得了一大批重要成果。较系统地总结了这些成果。总结本学科60年发展的经验,面向本领域重大工程技术问题,持之以恒地开展系统且深入的基础研究,仍是学科今后发展必须坚持的基本战略方针。