Temperature field in a well with casing induction heating: considering the natural convection influence

One of the promising methods of geophysical research in operating wells is active thermometry. The method consists in creating an artificial temperature field in a well due to local heating of the metal casing. Observation of heat tags movement enables determining the fluid flow rate in the well and identifying the intervals of the behind casing flow.

The article is devoted to the study of non-stationary thermal processes in a well during induction heating. The calculations were performed in the commercial simulator Ansys Fluent. It was established that with an increase in the volumetric flow rate through the column from 5 to 50 m³/day for the modeling conditions, the maximum heating of the liquid (a change in the average mass cross-section temperature) is reduced by 85 %, and the maximum heating of the column is reduced by 7 %. The influence of natural convection on the formation of a temperature field in a liquid and a column has been studied. For the model with natural convection accounted, the column heats up significantly less than for the model without convection: the error in calculating the temperature changes due to neglect of natural convection can reach several hundred percent. During the process of induction heating for the casing, the effect of natural convection remains significant throughout the entire flow range of 5–50 m³/day.