Improved kinetic Equations for a NaNO2/NH4Cl Heat Generating System and their Implications in Oil Production

Resumo

A NaNO₂/NH₄Cl heat generating system has been widely applied in oil production process in China, for paraffin plug removal, in-situ fracturing, etc. Establishing an accurate kinetic equation for the NaNO₂/NH₄Cl system is important for field operation applications. In this study, based on a strictly controlled group of experiments, the kinetic equation for the NaNO₂/NH₄Cl heat generating system is established and regressed by the method of undetermined coefficients, on condition that the heat loss of the reaction is relatively small and could be neglected. It is obvious that in many field applications the heat loss is considerably high and cannot be neglected; hence the equation is improved by taking into consideration the heat loss input. The improved equation shows a better correlation with experimental data, particularly for long reaction times. The established equation reveals the relationship between the reaction rate and the concentrations of the reactants and catalyst This study has practical significance for calculating the temperature field near the well bore and can be used for parameter optimization of the NaNO₂/NH₄Cl heat generating system.