Interpretation And Processing Of Gas Well DTS Test Data

At present,natural gas resources are a relatively environmentally friendly energy source,and the development of gas reservoirs has important development potential and value.In the process of gas well development,temperature is one of the essential production test parameters,which is very important for geological data interpretation and dynamic monitoring.Conventional temperature measuring instruments include resistance thermometers and thermocouple thermometers.They are often combined with turbine flowmeters and quartz crystal pressure gauges for measurement in the production profile.There are problems of delay and limited measurement time for temperature.Distributed fiber optic temperature sensor(DTS)utilizes the principle of Raman scattering and optical time domain reflection to carry out long-term measurement in the production profile and provide real-time,continuous and accurate formation temperature data.Through the large amount of temperature data measured by DTS,the flow situation at the bottom of the well is restored as much as possible,and its appearance makes up for the shortcomings of traditional thermometers.The domestic interpretation of DTS data mainly relies on foreign models and software.The core algorithms in these commercial software are kept secret,which limits the popularization and application of this technology.Therefore,this paper studies the wellbore transient temperature model,and interprets and analyzes the DTS test data based on the improved wellbore transient temperature model.The main research contents of the thesis include:(1)Extensively investigate relevant literature on wellbore temperature models at home and abroad.Mainly investigate the derivation process of the wellbore temperature model,summarize various thermophysical parameters involved in the heat transfer process,and select an appropriate temperature model.(2)Qualitative and quantitative analysis of DTS data,and visual processing.(3)Learn about DTS interpretation and processing software at home and abroad,such as PLATO-DTS,Emeraude-DTS,etc.,and analyze and compare the thinking process of the two software.(4)Using numerical simulation software,combined with geological models,wellhead output information and other data,based on conservation equations,wellbore heat conduction theory and wellbore flow mechanism,simulate the temperature field in the wellbore,predict the temperature profile of the wellbore,and obtain the fluid flow rate Parameters such as,perforation size,and bottom hole temperature will have a greater impact on the wellbore profile;formation conductivity has less impact on the wellbore temperature profile.(5)Through the established wellbore transient temperature model,the geothermal gradient in the well shut-in state is obtained,and the fluid temperature in the open well state is combined with the flow equation to obtain the flow rate of the production layer,which is compared with the flow rate of the production layer obtained by the DTS processing software.The model was found to have a certain reliability.