A phenomenological model for formation damage by chemical and mechanical processes in petroleum reservoirs is presented. Geochemical reactions involving dissolution/precipitation and ion exchange are modeled. The precipitates are considered mobile and mixed with formation particles to contribute to the pore throat plugging. Size distribution of both precipitates and clay fines is represented by a bimodal distribution function. A semi-empirical approach is used to estimate the fraction of the plugged pore throats. The model parameters are determined through an optimization method by matching the model predictions to laboratory core test data.
The capability and validity of the model are demonstrated by comparing the predictions obtained from this model with experimental data for four cases. The predicted and the experimental data are shown to be in good agreement in each case. This model can be used for diagnosis, evaluation, and simulation of damage and alteration of reservoir formation during drilling, production, and chemical flooding processes.