Study On The Process Optimization Of Underground Gas Storage Injection Production System In HUTUBI

With the rapid development of the natural gas market and the pipe network system,the security and reliability requirements of gas supply attract much more attention.Underground natural gas storages have become one of the most important components of pipe network system for the usages in balancing the pressure and transmission volume of natural gas pipelines and regulating regional gas supply.In this paper,the ground gas production and injection system in Hutubi gas storage is investigated and analyzed,and the injection and production operation data are analyzed.And the characteristics and existing problems of gas storage operation are reviewed.The prediction model of gas injection and production process is established.By comparing with the field data,the prediction error for gas production system is less than 10%,and the prediction error for gas injection system is less than 5%.The correctness of the model is verified.For throttling and hydrate control in the process of gas storage injection system,this paper on the basis of operation analysis of Hutubi gas storage injection system,with the help of simulation for gas hydrate formation prediction,completes optimization control of hydrate.Depending on the hydrate model and field data,an optimized scheme was presented.From the point of economy and security,the optimized methanol concentration is 16-20%.Comparing the expense of inhibition method in field with the heating method,the better hydrate prevention scheme in gas production system of Hutubi gas storage was provided.The optimized hydrate prevention scheme reduces energy consumption and provides instructions for the operating of the Hutubi gas storage.Simulation studies of the ethylene glycol regeneration process are conducted at the same time and the influences of process parameters on device energy consumption are analyzed.The optimal operation parameters of ethylene glycol as the antifreeze are given combining temperature,pressure and actual production conditions together.In addition,after the sensitivity analysis of the stabilizer parameters is conducted,stabilizer parameters are optimized.According to optimization theory and gas injection process operation data analysis,two optimization schemes are proposed combing gas injection well open and gas injection compressor boot.These two schemes are based on the operation optimization of the existing network and the staged gas injection.The process of gas injection is adjusted and a new gas injection process which reduces the energy loss(energy consumption of the compressor,throttle energy consumption)is proposed.The reduction of average energy loss for the two schemes above are 11.11 % and 13.25 %,respectively.The technical supports are provided for the safe operation of the gas storage system.This paper completed the establishment of the evaluation system of gas injection and recovery.An index which includes gas injection system efficiency and energy consumption per unit gas injection pressure is proposed in order to better reflect the operation parameters.With this index,the energy consumptions in the injection-production cycle can be fed back by the evaluation system more intuitively,which can lay the foundation for energy optimization.In addition,an overall analysis and evaluation of the operation energy consumption in injection-production cycle are carried out combing the evaluation system.