Fluid filtration to a horizontal well with variation in the parameters of the damage zone

This paper considers the problem of steady filtration flow of an incompressible single-phase fluid in the vicinity of a horizontal well with varying permeability in the damage zone. The effects of various parameters of the damage zone on the productivity of the horizontal well was numerically investigated on the basis of a filtration equation using the Darcy law. It is shown that effect of some parameters (size of the damage zone, damage ratio, and permeability profile shape) on the well productivity is rather significant. An analytical approximation of the relative productivity of a horizontal hole in an isotropic formation with allowance for the main parameters of the damage zone is proposed. An expression for the skin factor due to the formation contamination was obtained.