Study On Downhole Complex Judgment And Analysis Method Based On Wellbore Temperature And Pressure Field

With the continuous deepening of exploration and development,the target well depth faced by drilling and completion projects has continued to increase.The complex geological conditions of oil and gas reservoirs make loss and well kicks occur frequently during drilling and completion construction,which affects the safety of operations and damages the integrity of the wellbore.Among the many relevant physical parameters in the drilling and completion process,temperature and pressure are the most direct and important parameters that affect and reflect the fluid state in the wellbore.Therefore,the continuous temperature and pressure field distribution in the wellbore should be accurately obtained,and a matching algorithm should be established to analyze the measured data.Processing and analysis are of great significance for timely judging downhole working conditions and formulating reasonable countermeasures during drilling and completion.Based on the new wellbore micro-measurement chip tool,this paper focuses on the research on the supporting algorithms of the new chip tool,such as data correction and reconstruction methods,downhole complex discrimination and parameter quantitative inversion methods.Firstly,the calculation model of wellbore temperature field and pressure field for three working conditions,such as normal circulation,downhole leakage,and downhole gas invasion,was established,and the variation laws were analyzed.The accuracy of the model is tested and validated.Secondly,according to the working principle and characteristics of the micromeasurement chip tool,the spatio-temporal conversion of measurement data and the reconstruction of the wellbore temperature and pressure field are established,and the temperature and pressure measurement data obtained by the tool are converted from time series to depth series.The random error between the measured value and the predicted value was corrected by the Kalman filter algorithm.Thirdly,a method for judging the occurrence of complex downhole by using microchips to measure temperature and pressure data,establishing wellbore temperature and pressure difference profile,structural displacement pressure difference and discriminating pressure difference is proposed,and a Kalman model of leakage and gas invasion conditions is established.The filter inversion model has quantitatively predicted the depth and rate of complex downhole occurrences.Finally,the bidirectional data communication transmission mode between the host computer and the micro-measuring chip is designed,and the development and writing of the related function modules of the simulation and analysis software of the supporting software of the micro-measuring chip are completed by using C# language.Based on the temperature and pressure measurement data characteristics of the downhole microchip tool,this paper establishes a series of supporting algorithms such as data correction,reconstruction,complex discrimination and parameter inversion,and develops supporting software function modules,which provide the practical application of the tool in the field.Strong data basis and theoretical support are of great significance for ensuring safe and efficient drilling and completion operations.