中俄原油管道漠大线运营后面临一些冻害问题及防治措施建议

Frost hazards and mitigative measures following operation of Mohe-Daqing line of China-Russia crude oil pipeline

基于世界上几条多年冻土区修建输油气管道的经验,结合我国境内的中俄原油管道漠河-大庆段(漠大线)现场调查、油温监测和探地雷达等勘察结果,研究漠大线运营后可能面临的主要冻害问题、形成过程、影响因素、成灾机制、管道影响,提出预防和防治措施建议及进一步需要研究的主要问题。研究发现,目前漠大线面临的主要冻害问题包括融沉、冻胀丘、冰椎、冻土斜坡、冰刨蚀和潜在冻胀等,在管道持续运行和环境条件改变下,这些冻融灾害可能对管道造成一定的不利影响甚至破坏。现场油温监测显示,在2011年和2012年最低和最高油温分别为0.42℃和16.2℃,全年的正油温运行是造成目前管道周围冻土融沉的主要原因。冬季部分地段出现的冻胀丘、冰椎以及浮冰对管道形成一定的潜在威胁。研究成果为中俄原油管道漠大线以及规划建设的中俄原油管道二线、中俄输气管道、格尔木-拉萨输油管道改造工程以及其他多年冻土区输油气管道设计、施工、运营和维护提供参考和依据。

On the basis of the experiences from some pipelines transporting oil and gas in permafrost regions, this paper investigates the formation process, influential factors, causing mechanisms of frost hazards and their impacts on the pipeline according to the results from the field surveys and ground penetrating radar （GPR） detections along the Mohe-Daqing line of China-Russia crude oil pipeline （CRCOP）. In addition, some mitigative measures and research needs are proposed. Investigations show that the CRCOP has being encountered with some frost hazards including thaw settlement, frost mounds, icings, permafrost slopes, ice gouging and frost heave, which may cause damages to pipeline in the future. The monitored oil temperatures at three pumping stations show the lowest and highest oil temperatures are 0.42 ℃ and 16.2 ℃, respectively, during the period from 2011 to 2012. This year-round positive oil temperature becomes the predominant factor causing the current thaw settlement of permafrost surrounding the CRCOP in some sections. In the winter, the frost mounds, icings and floating ices potentially threaten the pipeline in some sections. The results can provide important references and bases for construction, design, operation and maintenance of the second CRCOP, the China-Russia gas pipeline, the Golmud-Lhasa and other pipelines in permafrost regions.