A multi-activity drilling assembly operable to be mounted upon a drilling deck of a drillship, semi-submersible, tension leg platform, jack-up-platform, or offshore tower and positioned above the surface of a body of water for supporting drilling operations through the drilling deck, to the seabed and into the bed of the body of water, said multi-activity drilling assembly including: a derrick operable to be positioned above a drilling deck and extending over an opening in the drilling deck for simultaneously supporting drilling operations and operations auxiliary to drilling operations through the drilling deck; a first top drive positioned within the periphery of said derrick; a first drawworks positioned adjacent to said derrick and operably connected to a first traveling block positioned within said derrick adjacent to said top drive for conducting drilling operations on a well through the drilling deck; a second top drive positioned within the periphery of said derrick; a second drawworks positioned adjacent to said derrick and operably connected to a second traveling block positioned within said derrick adjacent to said second top drive for conducting drilling operations or operations auxiliary to said drilling operations extending to the seabed for the well; and means positioned within said drilling derrick for transferring tubular assemblies between a first top drive station and a second top drive station to facilitate simultaneous drilling operations and operations to the seabed auxiliary to said drilling operations, wherein drilling activity can be conducted within said derrick with said first or second top drive, said first or second drawworks and said first or second traveling block and auxiliary drilling activity extending to the seabed can be simultaneously conducted within said derrick with the other of said first or second top drive, the other of said first or second drawworks and the other of said first or second traveling block. view more

A multi-activity drilling assembly as defined in claim 10 wherein said means for transferring includes: a rail assembly operably extending between a position adjacent to said first top drive station and a position adjacent to said second top drive station; a first tubular handling apparatus mounted to traverse upon said rail; and a second tubular handling apparatus mounted to traverse upon said rail, wherein tubular assemblies may be operably transferred between said first top drive and said second top drive to facilitate simultaneous drilling operations and operations auxiliary to said drilling operations. view more

A multi-activity drilling assembly as defined in claim 11 and further including: a first tubular setback envelope positioned adjacent to said first top drive station; and a second tubular setback envelope positioned adjacent to said second top drive station. view more

A multi-activity drilling assembly as defined in claim 12 and further including: a tubular handling system for transferring tubular assemblies between said first tubular setback envelope and said second tubular setback envelope and said first top drive station and said second top drive station. view more

A multi-activity drilling assembly operable to be supported from a position above the surface of a body of water for conducting drilling operations into the bed of the body of water, said multi-activity drilling assembly including: a drilling superstructure operable to be mounted upon a drilling deck for simultaneously supporting drilling operations for a well and operations auxiliary to drilling operations for the well; first means connected to said drilling superstructure for advancing tubular members into the bed of body of water, wherein said first means includes a first means for hoisting tubular members; second means connected to said drilling superstructure for advancing tubular members simultaneously with said first means into the body of water to the seabed, wherein said second means includes a second means for hoisting tubular members; and means positioned adjacent to said first and second means for advancing tubular members for transferring tubular assemblies between said first means for advancing tubular members and said second means for advancing tubular members to facilitate simultaneous drilling operations auxiliary to said drilling operations, wherein drilling activity can be conducted for the well from said drilling superstructure by said first means for advancing tubular members and auxiliary drilling activity can be simultaneously conducted for the well from said drilling superstructure by said second means for advancing tubular members. view more

A multi-activity drilling assembly operable to be supported from a position above the surface of a body of water for conducting drilling operations to the seabed and into the bed of the body of water, said multi-activity drilling assembly including: a drilling superstructure operable to be mounted upon a drilling deck for simultaneously supporting drilling operations for a well and operations auxiliary to drilling operations for the well; a first tubular advancing station connected to said drilling superstructure for advancing tubular members to the seabed and into the bed of body of water; a second tubular advancing station connected to said drilling superstructure for advancing tubular members simultaneously with said first tubular advancing station to the seabed and into the body of water to the seabed; and an assembly positioned adjacent to said first and second tubular advancing stations operable to transfer tubular assemblies between said first tubular advancing station and said second tubular advancing station to facilitate simultaneous drilling operations auxiliary to said drilling operations, wherein drilling activity can be conducted for the well from said drilling superstructure by said first or second tubular advancing stations and auxiliary drilling activity can be simultaneously conducted for the well from said drilling superstructure by the other of said first or second tubular advancing stations. view more

A multi-activity drilling assembly operable to be supported from a position above the surface of a body of water for conducting drilling operations into the bed of the body of water, said multi-activity drilling assembly including: a drilling superstructure operable to be mounted upon a drilling deck for simultaneously supporting drilling operations for a well and operations auxiliary to drilling operations for the well; first means connected to said drilling superstructure for advancing tubular members into the bed of body of water; second means connected to said drilling superstructure for advancing tubular members simultaneously with said first means into the body of water to the seabed, and means positioned adjacent to said first and second means for advancing tubular members for transferring tubular assemblies between said first means for advancing tubular members and said second means for advancing tubular members to facilitate simultaneous drilling operations auxiliary to said drilling operations, wherein drilling activity can be conducted for the well from said drilling superstructure by said first means for advancing tubular members and auxiliary drilling activity can be simultaneously conducted for the well from said drilling superstructure by said second means for advancing tubular members. view more