The effect of changes in filtration properties of the near-well producing zone (NWPZ) on the reservoir external boundary radius (r к ) and on the well production rate is considered. On the basis of analytical calculations it is demonstrated that the dimensions of the drained reservoir zone decrease with impairment of the NWPZ properties. Therefore, with due account of r к changes, the fluid inflow reduces to a less extent than without regard for r к changes.