Pengchao Chen

Study on a Method Monitoring Oil and Gas Pipelines in Permafrost Regions

Based on conditions of oil and gas pipelines in permafrost regions, this paper demonstrates a method for monitoring pipeline stress and displacement as well as permafrost temperature field. To measure pipeline displacement, Total Station measuring technique which calculates displacement by measuring the change of pipeline sign post was adopted; and to monitor pipeline stress and temperature field of permafrost, Fiber Grating Sensing technique was used. This method has been applied to Pipeline No. A for a year, according to the test results, during the year, displacements of different degrees have been occurred to the pipeline; this pipeline was not influenced by frost heave in winter but was influenced by thaw collapse in summer. Due to this monitoring method for oil and gas pipelines in permafrost regions, the condition of permafrost and the change of pipeline under the impact of permafrost were successfully monitored; therefore, this method is effective and feasible.Copyright

A Fiber Bragg Grating Sensing System and Its Application to Monitoring Landslides and Associated Pipelines

The integrity of oil and gas pipelines is seriously threatened by landslides and other geohazards in tough terrain in western China. Monitoring the landslides with slow, continual movements and the strain build up in pipelines due to landslides is an effective way to maintain the serviceability of pipelines. In this paper, a monitoring system based on Fiber Bragg Grating (FBG) sensors is developed and applied. The system is made up of four related parts: the pipeline strain measurement of the with FBG strain sensors, the soil-pipeline contact pressure detecting with FBG soil pressure cells, the landslide inner deformation monitoring with pipe strain gages and the landslide surface monitoring with a special buried concrete beam with FBG sensors. The system is used to monitor a huge, slow moving landslide and the pipeline affected by it. The monitoring results are analyzed and the pipeline integrity is assessed basing the monitoring results. The FBG system has been proved to be suitable to monitor landslides and pipelines automatically and real-timely.Copyright