Riserless drilling with casing: GOM well design model requires change for deepwater drilling

A significant improvement in deepwater well integrity can be accomplished by deepening the structural casing to have dual functionality. This exploits the rapid growth of formation strength in shallow first 1000 - 2000 ft below the seafloor. This 1st casing string in the deepwater would firstly, support the axial and bending loads if the wellhead. blowout preventer, riser and subsequent casing strings, as in the current practice and secondly, provide sufficient casing shoe strength to mitigate the shallow drilling hazard.