Study On Controlling Of Online Pigging Operation During The Long Distance Pipeline Transportation Of Nature Gas

Transport efficiency and working life of gas pipeline depends largely on the cleaning condition of the pipeline,therefore it is necessary to carry out pigging operation before and after putting into production.Due to the high velocity of medium in the pipeline and the larger throughput and asymmetry of medium,especially it is very difficult to carry out pigging operations and control of the running-speed in the non-stop operation condition.Improper control of velocity of the pig will lead to blocking or damage of reclaim equipment,so it is not easy to control the running speed of the pipe go-devil.The Ji-Zi pipeline puts into use officially in June 2002 and the design pressure of Ji-Zi pipeline is 6.4MPa.The starting of Ji-Zi pipeline is Ji Nan gas transmission station,which located in the LiCheng district;The ending of Ji-Zi pipeline is Linzi gas transmission station,which located in the Linzi district,gas transmitting volume is 5×10~6 m~3/d.Because of pigging operation and inner inspection are not being achieved after the ten years of being put into production,therefore no one grasps the through capacity of pipeline and the loading capacity and degree of cleanliness,and so on and so forth.On the one hand,this paper studies the controlling of the running-speed with the online pigging practice in Ji-Zi pipeline section in the non-stop operation condition.According to the velocity model calculation analysis and Newton's second law and the law of conservation of energy,the running state is timely mastered and predicted.The running speed of the pipe go-devil is controlled in the safe and reliable range by adjusting the process parameters,which carries out the normal running of the pigging operation;On the other hand,kinds of possible risk factors and reasons for pigging are discussed and investigated further by our company combing with extensive experience in this paper.Otherwise,some targeted risk factors and control measures are proposed in this paper to ensure pigging safety in the future during the long distance pipeline transportation.At last,contrast analysis of the intelligent pigging operation efficiency and throughput of the pipeline before and after the change,the intelligent pigging operation economic benefit is obtained the related conclusion.