Abstract: A vacuum sub (8) for use in a well bore (12), the vacuum sub (8) having a cylindrical casing (28) with an upstream end (14) and a downstream end (16). The upstream and downstream ends (14, 16) are designed to attach to components of a downhole assembly (6) in a well bore (12). The vacuum sub (8) includes a port (18) in the cylindrical casing (28) that provides access between the inside (20) of the cylindrical casing (28) to the outside (22) of the cylindrical casing (28). The port (18) is angled so that when air passes through the port (18) from the inside (20) of the casing (28) to the outside (22) of the casing (28), the air is directed upwardly through the well bore (12) in an upstream direction, thereby creating a vacuum in the well bore (12) below the port (18).