Numerical Simulation For Wellbore And Formation Temperature Distribution In Oil Wells

Based on the theory of porous medium flow and the porous medium heat transfer, the temperature field models of the welibore and adjacent formation have been constructed for production wells. While wells are producing, heat transfer in welibore is considered as heat conduction and convection in continuous media in vertical tube, heat transfer in production zones is considered as heat conduction and convection in porous media, heat transfer in adjacent rocks is considered as heat conduction in porous media. While wells stop producing, because of stopping flowing in welibore and production zones, heat transfer in welibore is considered as heat conduction in continuous media in vertical tube, and heat transfer in formation is considered as heat conduction in porous media.For the actual situation of multiplayer production in most oil wells, velocity and flow change are considered in the model while fluid moves up the well, and conservation equation including continuous equation, momentum equation and energy equation are solved together. According to actual situation of production wells, external boundary conditions and coupled inner boundary conditions between welibore and adjacent rocks, welibore and production zones, adjacent rocks and production zones are constructed, and an alternate direction implicit finite difference algorithm(ADI) is used to solve temperature models.Downhole temperature profiles have been simulated under different conditions of fluid output, production time, off production time, formation parameters, geothermal gradient, bed thickness, welibore radius and so on, and simulation results are analyzed and discussed. Though simulating the temperature profile of X9-D4-332 in Daqing oil field, and comparing it with temperature log, a good result is achieved.