Numerical Calculations of Strong Temperature Gradients at Interfaces of Horizontally Stratified Sediments

Abstract

Measurements of temperature gradients carried out in oil wells immediately after interruption of production frequently show negative values. Such negative values are in contradiction to a stationary temperature field. The temperature field is calculated with the help of an Explicit Finite Difference scheme for a simulated production process during and after production. The gradients formed at the interfaces of sediment layers, which are identified with that of the thermal diffusivities, are called strong gradients. Their dependence on the duration of the production process and on the contrast of the thermal diffusivities, and also their growth and disappearance after production stops are shown and discussed.