长输管道严密性漏失检测新方法  

New Method to Detect Leakage in Long-distance Pipelines

作　　者：田园[1] 欧剑[2] 贺三[3] 谢英[3] 江茂泽[3] 袁忠明[3] 胡安鑫[4] 

机构地区：[1]重庆科技学院石油工程学院油气储运教研室 [2]西南油气田分公司输气管理处 [3]西南石油大学石油工程学院 [4]四川科宏石油天然气工程有限公司重庆项目部

出　　处：《油气储运》2010年第8期609-612,共4页Oil & Gas Storage and Transportation

摘　　要：运用连续性方程、动量方程和状态方程转化而成的非线性偏微分方程组描述了天然气长输管道的试压漏失流动情况。采用线性化方法,将非线性偏微分方程组简化成线性热传导方程。根据试压阶段气体运行的特点,建立了描述天然气长输管道试压阶段单点泄漏的线性偏微分方程模型。将漏失位置和漏失强度的辨识转化为关于微分方程边界条件反演的偏微分方程反问题,并根据严密性试压特点,给出了确定泄漏位置、泄漏强度系数与泄漏衰减系数的2个补充条件。采用Laplace积分变换导出了计算泄漏位置、泄漏强度系数和泄漏衰减系数的数学表达式。在此基础上应用"压缩映像原理"构造数值计算格式并编制了计算机程序。实际算例的计算值与实际情况吻合较好,可基本满足输配气管网试压阶段泄漏检测的需求。Adopting nonlinear integral-differential equations converted from equation of continuity,momentum equation and state equation describe leakage situation in pressure testing of long-distance gas pipeline.Based on linearization technique,nonlinear integral-differential equations are simplified into linear heat conduction equation.According to the characteristics of gas running during pressure testing stage,linear integral-differential equation model that describes individual point leakage of long-distance gas pipeline during pressure testing stage is established.Identification on leakage level at leakage location Is transformed to the inverse problems of partial differential equation on boundary condition inversion of differential equation,and two supplementary conditions to determine leaking location,leaking level coefficient and leakage attenuation coefficient are given according to the characteristics of leakage pressure testing.A mathematical expression to calculate leaking location,leaking level coefficient and leakage attenuation coefficient is derived by means of Laplace integrate transformation.On that base,numerical calculation form is set up with 'contraction mapping theory',and a code procedure is formulated.Calculation results from an actual case show that calculation values are perfectly fitted to actual situation,which can meet the needs of leakage detection for gas transmission and distribution networks during pressure testing stage.

关 键 词：长输管道 试压 泄漏检测 强度系数 衰减系数 Laplace积分变换 反问题 

分 类 号：TE973.1[石油与天然气工程—石油机械设备]