Abstract: An offshore drilling rig contains a heavy-duty support cart that straddles the moonpool and rides on rails. A funnel-shaped hole extends through the support cart, and a cutout on one side of the cart provides lateral access to the hole. The cart can be moved to the region of the rotary assembly, where a length of tubulars can be suspended from the cart. For instance, when the BOP is pulled out for installation of the Xmas tree assembly, the BOP and attached riser can be pulled up above the seabed and hung from the support cart, then moved laterally out of the way while the Xmas tree assembly is installed. This lateral movement lowers the possibility of collision between the BOP and Xmas tree assembly. The BOP assembly can then be disassembled and at a later time, or hung until is needed for an adjacent borehole. In a preferred embodiment, the cart is included on multi-activity rigs with more than one load path, hoist, and rotary assembly.

Abstract: An offshore drilling rig contains a heavy-duty support cart that straddles the moonpool and rides on rails. A funnel-shaped hole extends through the support cart, and a cutout on one side of the cart provides lateral access to the hole. The cart can be moved to the region of the rotary assembly, where a length of tubulars can be suspended from the cart. For instance, when the BOP is pulled out for installation of the Xmas tree assembly, the BOP and attached riser can be pulled up above the seabed and hung from the support cart, then moved laterally out of the way while the Xmas tree assembly is installed. This lateral movement lowers the possibility of collision between the BOP and Xmas tree assembly. The BOP assembly can then be disassembled and at a later time, or hung until is needed for an adjacent borehole. In a preferred embodiment, the cart is included on multi-activity rigs with more than one load path, hoist, and rotary assembly.