A COMPUTATIONAL IMPLEMENTATION FOR TRANSIENT TEMPERATURE FIELD ANALYSIS AROUND A CASED AND CEMENTED WELLBORE BASED ON ANALYTICAL SOLUTION

Palavras-Chave: Injecao de vapor, Conducao de calor, Reservatorios de oleo pesado Abstract - Estimation of the temperature field around a wellbore is an important problem in petroleum engineering. Heat is transferred between the borehole and the formation during thermal recovery techniques, inducing stresses that may affect the structural wellbore and formation stability. Temperature field around the well is usually evaluated by numerical techniques such as the finite difference method or numerical inversion of Laplace transform, assuming a constant temperature at the borehole wall. The method proposed herein considers the radial heat conduction through the bore-face. Cylindrical multilayer of heterogeneous materials in perfect thermal contact and with constant physical properties composes the geometry of the problem. The heat conduction equation is evaluated through the separation-of-variables method, using Bessel functions. The problem domain is defined at the finite interval bounded by the radius of thermal influence, evaluated as the heat front advances. At the borehole wall, the boundary condition is given by a constant heat transfer rate. The solution implemented in a computer program presented a good computational performance in terms of time and model simplicity.