Bit packer for dual tube drilling

A packer for use with a string of dual concentric drill pipe comprising:

• a cylindrical body;
• means defining a first passageway in said body communicating with the annular conduit between the inner and outer pipes of said string to provide a first flow path from surface to bit;
• means defining a second passageway in said body communicating with the inner pipe of said string to provide a second flow path, isolated from said first flow path, to permit cuttings to be carried from the bit vicinity to surface;
• means at the bottom of said body for receiving a bit;
• packing means mounted rotatably on said body above said bit to seal the annular space between said body and the hole wall;
• and
• a milling collar mounted on said body above said packing means.

A packer for use with a string of dual concentric drill pipe above a bit comprising:

• an inner tubular member including means for providing fluid-tight interconnection with the inner pipe of said string to provide a conduit for drilling fluid and cuttings from bit to surface;
• an outer tubular member arranged concentrically with said inner member and including means for providing fluid-tight interconnection with the outer pipe of said string to provide an annular conduit for drilling fluid from surface to bit;
• packing means encircling said outer member and adapted to contact the hole wall and seal the annular space between the hole wall and the outer member, said packing means being mounted rotatably with respect to said outer member;
• and
• first port means in said outer member providing fluid communication between said annular conduit and said annular space, wherein said packing means is slidably mounted on said outer member to close said port means to fluid flow when the bit is in drilling position at the hole bottom and to open said port means when said bit is lifted up from the hole bottom.

A packer for use with a string of dual concentric drill pipe comprising:

• a cylindrical body;
• means defining a first passageway in said body communicating with the annular conduit between the inner and outer pipes of said string to provide a first flow path from surfact to bit;
• means defining a second passageway in said body communicating with the inner pipe of said string to provide a second flow path, isolated from said first flow path, to permit cuttings to be carried from the bit vicinity to surface;
• packing means mounted rotatably on said body above said bit to seal the annular space between said body and the hole wall;
• and
• port means in said body providing fluid communication between said first passageway and said annular space, wherein said packing means is slidably mounted on said body and cooperates frictionally with the hole wall to slide upwardly and downwardly on said body to respectively close and open said port means when said body is moved respectively downwardly and upwardly in said hole.

A packer for use with a string of dual concentric drill pipe comprising:

• a cylindrical body;
• means defining a first passageway in said body communicating with the annular conduit between the inner and outer pipes of said string to provide a first flow path from surface to bit;
• a second passageway in said body communicating with the inner pipe of said string to provide a second flow path, isolated from said first flow path, to permit cuttings to be carried from the bit vicinity to surface;
• means at the bottom of said body for receiving a bit;
• packing means mounted rotatably on said body above said bit to seal the annular space between said body and the hole wall;
• and
• port means in said body to provide fluid communication between said annular space and said second passageway.

A packer for use with a string of dual concentric drill pipe comprising:

• a cylindrical body;
• means defining a first passageway in said body communicating with the annular conduit between the inner and outer pipes of said string to provide a first flow path from surface to bit;
• means defining a second passageway in said body communicating with the inner pipe of said string to provide a second flow path, isolated from said first flow path, to permit cuttings to be carried from the bit vicinity to surface;
• packing means mounted rotatably on said body above said bit to seal the annular space between said body and the hole wall;
• and
• port means in said body providing fluid communication between said first passageway and said annular space.