基于移动边界的钻井井筒动态温度场研究

RESEARCH ON DYNAMIC TEMPERATURE FIELD MODEL OF DRILLING WITH A MOVING INTERFACE

准确地了解钻井过程中井筒及周围地层的温度变化对于安全、高效钻进具有重要的意义。针对钻井过程中钻头持续破岩而导致的温度动态变化,基于热力学第一定律和热传导理论,建立考虑移动边界的井筒动态温度计算模型,并通过现场试验进行了验证。研究结果表明,以往恒定井深的井筒循环温度模型会使计算结果偏小,考虑井深的变化和钻头附近的轴向传热使得井底循环温度的计算结果更接近于现场实际。该模型为准确地了解和预测井筒温度变化规律提供理论参考。

Drilling wellbore and surrounding formation dynamic temperature behavior plays an important role for drilling safety and efficiency. Based on the non-steady-state heat transfer theory,a dynamic wellbore temperature model was established with a moving boundary,the finite volume method was used to solve the model which was validated through field experiments.The results show that the previous research which considering constant well depth will cause a smaller result,considering the change of well depth and heat transfer in axial direction near drill bit makes the results of bottom hole circulating temperature more close to the actual measurement. The model provides a theoretical reference for better understanding and predicting the bottom hole heat transfer behavior.