Determination of accurate formation temperature is needed for drilling fluid and cement slurry design, determination of geo thermal gradients and geo thermal reservoir evaluation. Almost all known methods to determine the formation temperature are based on shut-in temperature recordings. All these methods require long shut-in periods and result in estimates which are lower than the true reservoir temperature.
A new method has been developed that utilizes temperature recordings from short time flow tests to accurately determine formation temperatures, The temperature distribution prior to production was obtained by solving the diffusivity equation for conductive heat transfer during the circulation period. This provided the initial condition for solving the continuity equation for convective heat transfer during production by the method of characteristics. The application of the above solution is shown with a field example.