Solving Problems of Freezing and Blocking of Tail Gas Pipelines While Developing Oil Fields by Fire Flooding

In the process of oil field development by fire flooding, some sections of the tail gas gathering pipelines may get frozen and blocked due to high content in the gas of moisture, methane, ethane, carbon dioxide, and hydrogen sulfide. To solve this problem, investigations were conducted to determine the effect of tail gas components, flow rate, pipeline length, and surrounding temperature on the process of reduction of transmission capacity of the gas pipelines due to freezing and blocking. It was found that the methane content in the gas is mainly responsible for gas hydrate formation and wall freezing, which occur predominantly in the back parts of straight pipes and pipe elbows and junctions. According to calculations, 70% methanol concentration is the best hydrate inhibitor.