Pigging And Testing Technology In East Gas Transmission Pipeline Research And Application

The Sichuan to East Gas Transmission Pipeline has been put into commercial operation more than three years, which transmits natural gas nearly200×108m3. While providing users with a large number of clean energy, the Sichuan to East Gas Transmission Pipeline has created good economic and social benefits. But in the process of running, due to contamination (such as the presence of fluid), pipeline brought impact on some of the stations. In line with the principle of the responsible for users, providing qualified products and ensuring the safe and smooth operation, Sichuan to east gas pipeline branch carried on the pipeline pigging and sections of the inspection work. The branch also solved problems of the stations, such as ice block etc and also had the preliminary understanding of the pipeline. With the extension of pipeline running time, the periodic pigging detection is the important measure to master the changes of pipeline internal conditions and ensure the safe and smooth running. Because the Sichuan to East Gas Transmission Pipeline is a single operation pipeline, it’s important to ensure the normal, safe and smooth operation of the pipeline for users along the pipeline.This paper studied the type of pig, the selection of test methods, technical parameters of pigging detection equipment, pigging detection technology, factors of pigging in special areas, risk analysis and response of pigging detection operations, etc. Mainly focusing on speed control of pig under the low capacity, the choice of operating pressure, hydrate formation&the influence of slug flow in the pigging process, spontaneous combustion of FeS in the process of pig receiving and the blocked reason of pig, and put forward the feasible solving measures.Research shows that in the running state of pipeline pigging detection operation, choose the right pig and pig launching order is the key to ensure whether pigging runs smoothly. For the unknown pipe, foam pig which can broken down by itself is preferred; For requires detection in pipe, pipe cleaning degree and pipeline capacity needs to be verified, so bowl or straight plate pig which has better clean-up effect and higher through capacity should be choose; Pig speed should be according to the actual situation of pipeline and control the speed by adjusting the process or operation parameters; Choose suitable pigging operation time and putting hydrate inhibitor can effectively prevent hydrate formation in the pipe and avoid the hydrate blocked the pipe; When the Pig blocked, the plugging reason should be analyzed and corresponding measures should be taken; For spontaneous combustion of FeS and other risk in the pigging operation, risk analysis also should be carry on in advance and take corresponding measures, so as to ensure pigging inspection complete smoothly and achieve the goal of pigging detection.