Downhole vacuum sub

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 ).

What is claimed: 
     
         1 . A vacuum sub for use in a well bore comprising,
 a cylindrical casing ( 28 ) having an upstream end ( 14 ) and a downstream end ( 16 ) arranged and designed to attach to components of a downhole assembly ( 6 ) in a well bore ( 12 );   said casing including a port ( 18 ) that provides access between the inside ( 20 ) and the outside ( 22 ) of the cylindrical casing ( 28 );   said port ( 18 ) is angled through said casing 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 up the well bore ( 12 ) in an upstream direction toward the surface of the well bore ( 12 ),   thereby creating a vacuum in the well bore ( 12 ) below the port ( 18 ).   
     
     
         2 . A method of circulating air in an oil, gas or water well, comprising the steps of:
 providing a cylindrical casing ( 8 ) within a well bore ( 12 ), the casing ( 8 ) having a port ( 18 ) arranged to allow air to pass from inside ( 20 ) of the casing ( 8 ) to the outside ( 22 ) of the casing ( 8 ), so that air is directed in an upstream direction toward the surface of the well bore ( 12 );   applying air to the vacuum sub ( 8 ) so that the air passes through the port ( 18 ) and into the well bore ( 12 ) in an upstream direction, thereby creating a vacuum in the well bore ( 12 ) below the port ( 18 ).   
     
     
         3 . The method of  claim 2 , wherein,
 the air passes through the port at the rate of approximately 600 scfm.