Mathematical modeling and experimental study of aluminothermic reaction applied to thermal plug and abandoment of oil wells

Abstract

© 2024 Elsevier LtdThermite is a powerful energetic material that has potential application in the plug and abandonment (P&A) process of wellbores. The solution named Thermal P&A has withdrawn attention of oil and gas operators all around the world as a prominent method to decrease costs and increase efficiency. Like any technology in its early developments, virtual simulations are effective to predict its viability. However, thermite reactions take place through a complex heterogeneous mechanism that may compromise computational modeling in the P&A scenario. Therefore, this study aims to present a practicable and valid method of computing the 2Al-Fe2O3 thermite reaction propagation in a macroscopic system. The modeled domain consists of a stainless-steel tube filled with the thermite mixture and described in cylindrical coordinates. The energy and species conservation equations are discretized and solved by finite difference methods assuming a constant kinetics rate. A disruption model is adopted to account for heat losses at aluminum vaporization. The numerical results are validated by experimental tests carried out in the same system. Numerical temperature profiles at the tube external surface replicated the experimental data obtained via thermocouples. Effects of tube radius and thermite porosity was investigated. The results showed that decreasing the thermite porosity would be more effective to melt the tube than increasing the internal radius.

Keywords