By the similar methods in References (1), (2), and (3), this paper presents productivity formulae for horizontal wells kith circular cylinder drainage volume, using a uniform line sink model. If top and bottom reservoir boundaries are impermeable, the circular cylinder drainage volume radius has significant effects on the horizontal well flow rate. If the reservoir has a gas cap or bottom water, the effect of the circular cylinder radius on flow rate can be ignored, and, under the same top and bottom boundary conditions, the productivity formulae for a circular cylinder drainage reservoir will reduce to the corresponding formulae for an infinite lateral extent reservoir, respectively. Therefore, for a horizontal well, different productivity formulae should be used under different reservoir boundary conditions.