长宁页岩气宁纳线大落差管段清管冲击应力与位移分析  

Analysis of pigging impact stress and displacement in the hilly section of Changning-Naxi pipeline of Changning shale gas transmission

作　　者：彭阳 安建川 罗敏 余进[2] 马学峰 杨红 别沁 刘颖 梁力 PENG Yang;AN Jianchuan;LUO Min;YU Jin;MA Xuefeng;YANG Hong;BIE Qin;LIU Ying;LIANG Li(Gas Transmission Division,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610215,China;PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610056,China)

机构地区：[1]中国石油西南油气田公司输气管理处,四川省成都市610213 [2]中国石油西南油气田公司

出　　处：《天然气工业》2021年第9期142-151,共10页Natural Gas Industry

基　　金：国家自然科学基金青年基金项目“天然气管道跨越结构在两相流突变激振力作用下的清管动力响应研究”(编号:51604233)、国家自然科学基金项目“天然气管道跨越结构清管动力响应实验及理论研究”(编号:51174172)。

摘　　要：长宁—威远国家级页岩气示范区页岩气外输干线宁纳线管道全长约110 km,因管线先后翻越多处短距离垂直落差较大的地段,给清管作业带来了较大的风险。为了确保后期清管作业的安全,并为清管方案制订、清管器选型以及清管过程监控等提供依据,首先研究了清管速度、管道内压、敷设坡度、摩擦系数、清管质量和土壤类型对大落差管段清管冲击应力与位移的影响规律;其次针对宁纳线某大落差管段清管过程,采用OLGA软件计算了清管器运行速度;进而通过综合考虑不同影响因素,利用ANSYS/LS-DYNA软件模块建立了清管动力学有限元模型,对管道底部弯头所受最大冲击应力与位移进行了计算;最后分析得出了已建成及处于设计阶段的大落差管道的安全清管条件。研究结果表明:①随着清管器运行速度、管道内压和敷设坡度的增加,清管器对大落差管段底部的冲击应力值增大趋势明显,但位移值涨幅不大;②增加清管器—管壁摩擦系数,冲击应力值呈现先减小后增加的特殊趋势;③土壤弹性模量越大,对管道的嵌固能力越强,因而冲击应力与位移也就越小;④宁纳线大落差管段在目前清管工况条件下能够进行安全清管作业;⑤基于极限清管速度计算,得到了以管道输量和高程差为表征的安全清管条件。Changning-Naxi pipeline,which is the shale gas transmission trunk of Changning-Weiyuan national shale gas demonstration area,is totally about 110 km long.It runs through many sections with larger vertical drop in a short distance,which brings greater risks to the pigging operation.In order to ensure the safety of later pigging operation and provide basis for pigging scheme preparation,pig type selection and pigging process monitoring,this paper firstly investigates the influence laws of pigging velocity,internal pipeline pressure,laying slope,friction coefficient,pigging quality and soil type on the pigging impact stress and displacement of hilly pipeline sections.Then,by taking the pigging process in one certain hilly section of Changning-Naxi pipeline as an example,the running speed of pig is calculated by using the OLGA software.Based on this,considering different influence factors comprehensively,the finite element model of pigging dynamics is established by using the ANSYS/LS-DYNA software module.And it is used to calculate the maximum impact stress and displacement of the elbow joint at the bottom of the pipeline.Finally,the safe pigging conditions for the hilly pipelines that have been built or are in the design stage are analyzed and clarified.And the following research results are obtained.First,with the increase of pig running speed,internal pipeline pressure and laying slope,the impact stress of the pig to the bottom of hilly pipeline section presents an obvious increasing trend,but the displacement doesn't increase greatly.Second,with the increase of pig-pipe wall friction coefficient,the impact stress presents a special trend of decreasing first and then increasing.Third,the larger the elastic modulus of soil is,the stronger its pipeline fixing ability is and correspondingly the smaller the impact stress and displacement are.Fourth,under the current pigging conditions,safe pigging operation in the hilly sections of Changning-Naxi pipeline can be ensured.Fifth,the safe pigging conditions characterized

关 键 词：页岩气 大落差管道 清管过程 冲击应力 冲击位移 有限元计算 安全清管条件 极限 清管速度 

分 类 号：TE973[石油与天然气工程—石油机械设备]