Wellbore Circulation Temperature Field Calculation And Software Development For Drilling

In recent years,with the continuous deepening of oil and gas exploration and development,there are increasing numbers of deep and ultra-deep wells,resulting in higher temperatures in the wellbore.This poses a great challenge to the stability of downhole instruments and fluid performance.In order to ensure the efficient development of deep oil and gas,some oilfield companies have employed wellhead drilling fluid cooling technology to lower the wellbore circulating temperature and ensure the stability of downhole instruments and fluid performance.Therefore,accurate calculation of wellbore circulating temperature is crucial.Based on the dynamic heat transfer mechanism of wellbore circulating fluid-wellbore-formation,this paper describes the well trajectory using a cubic spline function model and considers the impact of multiple factors such as formation properties,drilling fluid properties,drilling string motion status,normal and complex drilling conditions on the wellbore circulating temperature field.Several models for calculating the wellbore circulating temperature field under various conditions are established,and initial and boundary conditions are determined.The solution method was studied,and the multi-objective optimization algorithm(NSGA-II algorithm)was used to carry out the optimization research of wellbore circulation cooling,A wellbore circulating temperature field calculation software was developed using Python as the back-end,Pyqt5 as the front-end,and My SQL as the database.It can calculate the wellbore circulating temperature field under different conditions such as circulating,stopping circulation,and loss of circulation.In addition,based on the latest computer graphics visualization technology,the temperature calculation results are visualized,and 3D wellbore structure,3D drill string combination,3D annulus temperature translation,rotation,and zooming functions can be achieved.Furthermore,the evolution cloud chart of wellbore-fluid-formation temperature can be drawn to dynamically present the heat transfer process.In addition,through field case verification,the maximum error of wellbore temperature calculated based on the theoretical model in this paper is within 5%,which meets the requirements of engineering calculation,and provides a calculation means for accurate calculation of wellbore circulation temperature field and guidance of drilling fluid circulation cooling.