关键词: 井筒传热, 瞬态导热函数, 井筒热容, 近似解

Abstract: Transient heat-conduction time function is a crucial function for wellbore heat transfer in the process of steam injection for heavy oil production.All of the common transient heat-conduction time functions and related approximate solutions ignore wellbore heat capacity and other properties, but the heat capacity has obvious effect on the heat transfer in wellbore, especially in short time, so the error is large in the early days of steam injection.Based on a novel transient heat-conduction time function considering the effect of heat capacity of wellbore, a new approximate solution is obtained by the numerical fitting method and compared with those traditional approximate solutions, which only give good results in long time.The new approximate solution presents higher precision all the time, especially in the early period of steam injection.It is shown that the new approximate solution of transient heat-conduction time function is simple in form and easy to use, so it has good practicability in engineering with wider applicability.

Key words: wellbore heat transfer, transient heat-conduction time function, wellbore heat capacity, approximate solution