Geological Hazard Assessment of Long-Distance Gas Pipelines

Now, all over the world, geologic hazards have became primary threatens to the natural gas pipelines. Almost all the long-distance gas pipelines pass though diversiform geologic circumstances and encounter many sorts of geologic hazards such as sink, slope movement, mud/landslide and seismic threat etc. Because of the greatly sudden and destructive characters, the consequences of gas pipeline failure resulted from the geologic hazards are always grievous. Thus, it is an important task to predict and decrease the loss of the failure. Risk assessment can offer effective methods to managers to make preferable decisions to decrease the pipelines' risk level due to geologic hazards. The mechanisms of threatens of geologic hazards to the gas pipeline are analyzed. Based on this, risk factors of natural gas pipeline due to geologic hazards are recognized, including the failure likelihood and failure consequences, and the five-grade factor system is set up. Further more, the geologic hazard risk assessment model is developed. The likelihood model is developed to account for factors that cause each threat. The consequence model is developed based on statistical analysis, industry practice, and engineering judgment (input from subject matter experts (SME's)).