Three-Dimensional Spatiotemporal Deformation And Finite Element Numerical Simulation Analysis Of Hutubi Underground Gas Storage

With the sustained and rapid development of China's economy,the energy problem has become increasingly prominent and become a major problem restricting China's economic and social development.Natural gas from the environmental point of view and from an economic point of view,to ease and solve our energy problem is of great significance.Underground gas storage in the natural gas supply exceeds demand when the natural gas into the ground,natural gas demand will become large when the natural gas recovery,which can effectively regulate China's natural gas supply and demand balance.Xinjiang Hutubi underground gas storage(HTBUGS)is located in Hutubi,Xinjiang,China is currently running the largest underground gas storage,in the underground gas storage gas conditioning process,gas injection and gas production process will affect The surface deformation around the gas storage and the stress and strain state of the fault and the gas storage layer,which may induce earthquakes.In this paper,the underground gas storage in Hutubi,Xinjiang,is based on the irregular change of the injection pressure,and uses the built-in gas storage area deformation monitoring network.Based on the technique of mobile GPS observation and precision leveling,The three-dimensional space-time change state of the surface of the gas storage area under the pressure change is obtained,and the finite element theory is used to establish the underground gas storage based on the gas pressure,physical parameters and regional seismic geology and geophysical data.The three-dimensional finite element model of the reservoir is used to analyze the gas storage.The reliability of the finite element model is evaluated according to the existing deformation observation results.The main contents of this paper are as follows:(1)To cover the entire gas storage area,but also more accurately reflect the gas recovery process with the dynamic deformation of the crust.The gas storage deformation network composed of 34 levels and GPS integrated observation piers(both of which are buried in the bedrock)are arranged and are carried out at different stages in the injection and recovery period,gas production period and gas injection period.Surface level and vertical deformation of the field observation,of which the northeast of the 13 observation points as the focus of research.(2)To study the theory and method of vertical deformation correction,to effectively deal with field observation data,to obtain the vertical deformation range and error distribution of the surface,and to explain the deformation results scientifically and rationally.(3)The pressure difference in the process of gas injection will change the stress state and the medium properties in the internal and external faults of the gas reservoir.Through the horizontal and horizontal surface deformation control constraints,the combination level and the GPS boundary constraint,the numerical model Three-dimensional finite element dynamic simulation of underground gas storage structure.(4)Using the method of numerical simulation to obtain the large-scale surface subsidence law in the regional area,the relationship between stress-strain-deformation of gas storage is discussed,the stability of gas storage is evaluated,and the safety operation of the study area is supported,And the safety operation of underground gas storage in the injection cycle was evaluated.