Risk Prediction And Overall Security And Stability Research For Salt-rock Gas Storage Caverns

In recent years, the energy crisis has become a strategic threat to the development of countries in the world. International competition for energy resources becomes more and more intense. In our country, the energy shortage has become an important constraint for the economic and social development, with the continuous deepening of modernization. Salt rock underground gas storage is adopted around the world, because of its good features. Since2003, our country has stepped up the construction of underground energy reserves and more and more salt rock underground gas storages are put into use. Invisibility of the underground gas storage makes it a certain degree of risk and China’s underground salt rock structure is different from that in western countries. Therefore, combining with the actual situation of China’s salt rock underground reserves, it has great significance to study the risk analysis and prediction and system security stability of the storages. Some useful conclusions were finally obtained, which could provide scientific basis and technical support for the storage construction and safety operation.Based on stochastic mechanics and reliability mathematics, this article relies on the national key basic research and development program. Jintan salt rock gas storage is studied as engineering background. Combining the actual salt rock layer and geological conditions in our country, the risk analysis and prediction and system security stability of the storages is studied. The main contents are as follows:1. Based on the theory of stochastic mechanics, the influence to security and stability of the reservoir caused by time-varying pressure of the inner gas during operation period is studied and the variation of failure probability of the salt rock underground gas storage during operation period is obtained.2. According to the practical application of engineering, the influence to the stability of the gas storage caused by changing the velocity of gas recovery and injection is discussed. Change of failure probability is calculated.3. According to the theory of reliability mathematics, Markov probability prediction model is built. Risk analysis and life prediction of gas storage is studied based on its probability transition matrix.4. Strength reduction theory is introduced into security and stability study of the underground gas storage caverns. It is analyzed both in static state and long-term rheology state based on strength reduction theory. Overall safety factor of the caverns is given quantitatively.