管道运行温度和埋深对北极输气管道周围温度场的影响  

Influence of Pipeline Operating Temperature on the Nearby Temperature Field in the Arctic Gas Pipeline

作　　者：李欣泽 吴青柏[1,2] 金会军 LI Xinze;WU Qingbai;JIN Huijun(State Key Laboratory of Frozen Soils Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences;College of Resources and Environment,University of Chinese Academy of Sciences;Sinopec Petroleum Engineering Co.;Northeast-China Observatory and Research-Station of Permafrost Geo-Environment(Ministry of Education),Institute of Cold-Regions Science and Engineering,School of Civil Engineering,Northeast Forestry University)

机构地区：[1]中国科学院西北生态环境资源研究院,中国科学院冻土工程国家重点实验室 [2]中国科学院大学资源与环境学院 [3]中石化石油工程设计有限公司 [4]东北林业大学土木工程学院,东北林业大学寒区科学与工程研究院,东北林业大学东北多年冻土区地质环境系统教育部野外科学观测研究站

出　　处：《油气与新能源》2022年第4期58-67,共10页Petroleum and new energy

基　　金：中国科学院战略先导课题(XDA20100103)。

摘　　要：北极地区特殊的地质和岩土条件决定了常规的管道设计将面临巨大挑战,如,管道埋设深度和管道运行温度就没有标准规范可遵循。依托规划中的阿拉斯加天然气管道工程实际,利用管道与冻土热传导数值计算模型对不同埋深、不同运行温度下输气管道周围土体的温度场变化进行了研究。计算结果表明:5℃正温管道加剧了冻土退化,管底下方融化深度主要受管道运行温度的影响,在浅埋、中埋、深埋3种方式下30年最大融化深度分别达到4.2 m、5.5 m和6.5 m,其中管道深埋方式对融化圈的发展具有促进作用;-1℃冷输管道可以保护冻土,有效抬升人为多年冻土上限,维持管基土处于冻结状态,3种埋深方式下人为多年冻土上限分别抬升至0.38 m、1.09 m和1.55 m,其中管道浅埋方式影响最大。建议在不连续多年冻土区管道可以采取浅埋的敷设方式,同时,通过调控管道运行温度接近-1℃,既保证了管道结构安全、保护了冻土环境,同时还能减少施工作业、降低工程投资。The special geological and geotechnical conditions in the Arctic determine that conventional pipeline design will be confronted with great challenges. For example, there remains no standard guiding the buried depth and pipeline operating temperature. Based on the practice of the planned Alaska natural gas pipeline project, the numerical calculation model of heat conduction between pipeline and frozen soil has been used to study the temperature field variation of soil around the gas pipeline under different buried depths and various operating temperatures. The result shows that the 5 ℃ positive temperature pipeline aggravates the degradation of frozen soil while the thawing depth beneath the pipe is mainly affected by the operating temperature of the pipe. The 30-year maximum thaw depths of shallow, middle and deep burial are 4.2 m, 5.5 m and 6.5 m respectively. The way of pipeline burial depth can promote the development of thawing circle;-1 ℃ cold transmission pipeline can protect the frozen soil, effectively raise the upper limit of man-made permafrost, and maintain the pipe foundation soil in the frozen state. The upper limit of the man-made permafrost can be elevated to 0.38 m, 1.09 m and 1.55 m under three different burial depths, among which the shallow burial exerts the biggest influence. It is suggested that in the discontinuous permafrost region, the pipeline should be laid in the way of shallow burial. Mean while, by regulating the pipeline operating temperature close to-1 ℃,the pipeline structure safety is ensured, the frozen soil environment is protected, and the construction operation and project investment are decreased.

关 键 词：多年冻土 输气管道 土壤温度场 管道运行温度 埋深 数值评估 

分 类 号：TE973[石油与天然气工程—石油机械设备]