Wellbore Temperature Field Prediction in Marine Drilling

Abstract

With development of deep-sea oil and gas resources, the change of wellbore temperature will cause rheological change of drilling fluid, phase change of hydrate in wellbore, and other problems in marine drilling, which seriously affects wellbore flow safety. Therefore, based on energy conservation theorem and basic theory of heat transfer, the mathematical models and calculation method for wellbore temperature distribution in marine drilling are established, the sensitivities of different parameters are analyzed, and the prediction method of wellbore temperature field in marine drilling is formed. The change laws are obtained as follows: Wellbore temperature above mud line will increase and that below mud line will decrease with increase in drilling fluid displacement; wellbore temperature above mud line will slightly increase and that below mud line will decrease with increase in drilling fluid density; wellbore temperature above mud line will increase and that below mud line will keep steady with increase in inlet temperature; wellbore temperature will increase with increase in inclination angle in same vertical depth. This study provides theoretical guidance for the prediction of wellbore temperature field in marine drilling and lays an important foundation for safe construction design of wellbore flow.