Safety Analysis And Development Of Software Of Pipe Strength Of Pipe String In Underground Gas Storage

With the sustained and rapid economic development,China's natural gas consumption has increased sharply.Natural gas has become an important force to adjust the regional energy demand differences in China because of its characteristics of easy cleanliness and high calorific value.Underground gas storage is an important facility for natural gas storage.Compared with surface spherical tanks,underground gas storage has many advantages,such as large storage capacity,wide peak shaving range and large safety factor.Gas storage string is an important link between underground reservoir and ground users to ensure stable energy supply.In this paper,the underground gas storage pipe string as the research object,carried out four aspects of work:Firstly,on the basis of the existing research results at home and abroad,the stress of underground gas storage string during frequent and high-speed gas injection and production is analyzed,the geometric state of three-dimensional wellbore is analyzed,the deformation law of the string under various forces is explored,the basic equation of gas injection and production string is deduced,and the stress and non-linear basic equation of the string under special conditions are explored in detail.Secondly,the calculation method for strength analysis of gas storage string is provided.According to the logging data,the three-dimensional wellbore trajectory data of gas storage wells are fitted,and the three-dimensional wellbore trajectory view is established.According to different calculation models of the string,the calculation of the internal compressive strength and compressive strength of the string under different working conditions is realized,and according to the actual logging results,the string is realized.The calculation of residual strength of pipe string under different working conditions.The safety factor of the pipe string is calculated and the method for predicting the remaining service life of the pipe string is given.Thirdly,on the basis of the above research results and risk engineering theory,a fishbone diagram-fuzzy hierarchical comprehensive evaluation model is established to analyze the possible factors of pipeline string damage in underground gas storage.The risk index system of pipeline string in underground gas storage is determined by fishbone diagram method.The weight of evaluation index is obtained by analytic hierarchy process,and its membership degree is determined by fuzzy comprehensive evaluation method.Through risk assessment of gas storage string,the important factors affecting the safety performance of gas injection and production string are found out and suggestions for improvement are given.Finally,on the basis of theoretical derivation and numerical simulation,the basic information database of gas storage is established,the database of pipe type and damage of pipe string is compiled,and several calculation modules of the strength analysis software of underground gas storage pipe string are compiled,which can calculate the strength of pipe string,safety factor and residual life.