Modeling heat flux calculations in surface well-testing operations

During surface well-testing operations, the produced fluids, either oil or gas, are burnt through oil burners or gas flares, respectively. The heat radiation due to the combustion of these effluent fluids is a critical problem for the personal security and the integrity of the equipment. API-RP-521 gives recommendations according to the heat magnitudes, ranging from 500 Btu/ft2/h to 5000 Btu/ft2/h. To ensure safe operations, the heat fluxes must be evaluated and compared to the API recommendations to put in place protective water screens. Despite their influences on the heat distribution, the solid objects in the flame environment, such as tanks or containers are usually not taken into account in the “field” methods currently used. The model presented in this paper is an improved model managing the surrounding objects affecting the heat flux distribution. This model is called a radiosity model, and its formulation is very similar to the one used in global illumination problems. As described in this paper, the field methods tend to underestimate the heat flux in the space in between the flames and the first unoccluded solid bodies. On the contrary, the field methods overestimate the heat flux when there are occlusions between the solid objects in the scene.