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应用比例积分控制原理将瞬态传热模型预测结果与出口温度实测数据逐步进行反馈可准确预测原始静态地层温度.为此,本文基于井下各控制组件质量、动量及能量守恒原理,建立了实际井身结构与钻具组合条件下循环和停止循环期间井筒-地层温度分布全瞬态传热模型,应用全隐式有限差分法进行求解,并引入比例积分控制原理对比分析实测温度与预测温度的误差范围进而精确、快速获取原始地层温度.结合一口深井基础数据计算表明,套管下入深度改变了井筒-地层间热交换效率,进而影响了近井壁地层温度分布状况;同时,钻井过程中循环和停止循环作业过程改变了井下各控制组件的初始条件与边界条件,致使近井壁原始地层温度分布距离产生变化.建立的数学模型和研究方法可为石油钻井、地热井开采及地球深部原始地层温度信息准确、经济、快速获取提供理论基础.
According to the theory of proportional integral control, the temperature of the original static formation can be accurately predicted by the feedback of the predicted results of the transient heat transfer model and the measured data of the outlet temperature step by step. Therefore, based on the principle of mass, momentum and energy conservation of each control assembly, Body structure and the combination of drilling tools under circulation and stop cycle during the wellbore - formation temperature distribution of all transient heat transfer model, the application of all implicit finite difference method to solve, and the introduction of proportional integral control principle comparative analysis of measured temperature and predicted temperature error Range and thus obtain the original formation temperature accurately and rapidly.According to the calculation of a deep well foundation data, it shows that casing depth changes the efficiency of heat exchange between wellbore and formation, and then affects the temperature distribution of near-wall formation. Meanwhile, during the drilling process Circulation and cessation of cyclic processes change the initial conditions and boundary conditions of each control component in the well, resulting in changes in the temperature distribution of the original formation near the wall.The established mathematical models and research methods can be used for oil drilling, geothermal well extraction and primitive deep earth Stratospheric temperature information is accurate, economical, and quickly available On basis.