Detecting System Of Hydrate Blockage In Gas Pipeline With Pressure Wave Propagation Method

After oil and gas extraction,pipelines are usually transported from the gas field to the storage area and then distributed to various locations.During the operation of the oil and gas pipeline system,there may be some blockages such as paraffin,hydrate and asphalt in the process of low temperature or pressure fluctuation.The problem of hydrate plugging is more common in gas pipeline.When the blockage reaches a certain extent,it will affect the normal operation of the pipeline and even cause the pipe damage and other accidents due to the increase of local pressure of the pipe.It is an important guarantee to ensure efficient and safe operation of oil and gas pipeline.In actual engineering,on the other hand,realize the real-time monitoring on the performance of the pipeline can know when and where the clogging is generated,and the causes of pipe blockage.Then we can effectively prevent the hydrate plugging according to the pipeline operation conditions.Pressure wave method can supervise the jam in gas pipeline remotely,non-intervention in testing.It is able to detect the important parameters of the blockage,such as locate the congestion location,the length of the blockage,and the degree of blockage(area).In this paper,according to the challenge of hydrate blockage detection in gas transmission pipeline engineering,designed and developed a system of detecting hydrate plugging in pipe with pressure wave method.By simulating pipeline building,sensor type selection,test precision calibration works,then implementing the accuracy of the blockage detection,such as the position detection,block length and the blockage area for gas pipeline jam.The system can provide effective test of the actual gas pipeline transportation engineering.According to testing date to develop the monitoring and detecting theoretical model,which to provide theoretical support for prediction and prevention of hydrate blockage in gas pipeline.Firstly,the pipeline in the experimental system is designed by combining engineering,and the sensor and valve are selected.It can be used to simulate the blockage of the pipeline by using different internal diameter pipe sections,which can realize the adjustment of the blocking position and the length of the blockage.The gas transmission module can stabilize the gas and maintain the inlet pressure stability by using the gas cylinder group and the buffer tank.Measurement and data acquisition system composed by industrial control computer and date acquisition board,then using the Labview software programming,which has realized the dynamic pressure,static pressure date acquisition and parameter setting.The pressure test information can real-time display on the screen.Secondly,the experiment system of this paper is tested.In the experiment,the pressure wave is generated in the pipe by means of quick-acting value,and the position and degree of the plugging are calculated by detecting the reflection time and amplitude of the pressure wave.In this study,the accuracy of the plugging front location is higher,the location accuracy of the blocking distance is higher,and the detection error is larger.The frequency acquisition time parameter distortion of the dynamic pressure sensor should be selected at the frequency of 50 kHz,otherwise the time parameter will distortion.In the system test,it is found that the pressure wave generated by quick-acting valve will have the generation of oscillating shock wave,which will cause the pressure wave strength attenuation,and the detection accuracy of the degree of blockage will be affected.It is suggested that the amplitude cannot be used as the only element in the follow-up study,the attenuation of the pressure wave in the process of tube propagation should be fully considered,and the detection accuracy of the blockage area in the tube should be improved.