Gas Gathering And Transportation Technical Study In A Block Of Changqing Gas Field Second-Phase Suface Engineering

There are some difficulties in phase II when we were developing a block of Changqing gas field which was using multilayer commingled development mode,all those difficulties can be summed up as various well types and pressure decline rules,complicated production process,all those made it very difficult to determine the surface gathering&transportation system.According to the production characteristics of the block,we carried out a study of the technology of natural gas gathering&transportation and natural gas processing.When we were studying the gathering and transportation technology,we did all of the technical analysis,process optimization,economic comparison,simulation etc.Finally we find the main gathering technology of“using well chock at the beginning,in the middle time using the energy of the well,and then pumping,wellhead on-demand alcohol injection,single well gas-liquid separation test measurement by turns,gas-liquid two phase transportation,low-mid-pressure gas gathering in GGS,one place boost in GGS,centralized treatment in treatment plant".Our research was a bold innovation when we are using the low-mid pressure system,the adaptability is very well;The needs of gas field development in whole life was meted;pigging and separation process was combined which had improved the pipeline transportation efficiency,at the same time ensured the gas-liquid separation efficiency;the selected process of measuring was very economic and practical,to meet the different needs of measurement;boost process meet the production requirements,and the compressor selection was very reasonable and economy,which reduced the cost of operation.In the studying of the process technology research,we take into account of the terms of the raw natural gas H₂S,CO₂ content can meet the our requirements but hydrocarbon dew point does not,we considering the raw gas pressure and temperature conditions,we tried a variety of dewatering process analysis,comparative studies and optimization,and determine to use a propane refrigeration&low temperature separation process,the technology is mature and reliable,simple process,flexible operation,safety and environmental harmless,and is suitable for the project which has a very low raw gas pressure and need to control water and hydrocarbon dew point.At the same time,the auxiliary process of the treatment plant was studied,and the main auxiliary processes such as gas gathering and transferring,condensate oil degassing and methanol recovery were determined.Our achievement can give a guidance to the whole production process of the block and provide a reference for the other similar development mode.