Nonequilibrium fluid filtration in a heterogeneously contaminated near-wellbore zone

Based on mathematical modeling of fluid filtration in a heterogeneous environment, studies have been conducted to investigate the impact of near-wellbore zone contamination on production well productivity. А model of non-stationary nonequilibrium filtration in a semi-infinite heterogeneous formation with a harmonic perturbation at its boundary was considered. Using the method of separation of variables, a solution to the boundary value problem was obtained, using which the influence of contamination on well productivity was determined.