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.