Abstract: The wellbore temperature profile is the necessary parameter for exploitation and performance analyses of deepwater wells. However, the hole interval submerged in deepwater is too long, its heat transfer law in seawater is different from that in stratigraphic section, and the seawater temperature assumes the nonlinear distribution with well depth and the periodic change with the season, hence its temperature calculation in deepwater is much more complicated than in onshore and shallow sea oil fields. Based on the basic theory of heat transfer and wellbore heat transfer characteristics in seawater and strata, the mathmatic model of wellbore temperature-pressure coupling in deepwater is developed and calculated by Runge-Kutta iteration method. In this model the varied environmental temperature gradient, hole structure, casing oblique angle and heat transfer medium, etc. The case study shows that the model result is in accordance with the field data, and meets the demand for the development engineering or project.

Key words: deepwater well, deepwater environment, temperature profile, pressure profile, overall-heat-transfer coefficient