Patent ID: 9399891
Filing Date: 2016-07-26
CPC Classification: E21B

Claim Text:
1. A drilling system comprising: a platform forming a top of a stationary or floating structure; a moon pool formed in said stationary or floating structure and having an opening opened to both a top side and a bottom side of said stationary or floating structure; a work stand disposed at a bottom portion of the moon pool with being spaced away from the platform and protruding from a bow side of the moon pool toward a stern side of the moon pool; a derrick installed on the platform over the moon pool of said stationary or floating structure; a first activity installed on the derrick for forming a borehole in a sea-bed and carrying out installation of a casing pipe assembly and a blow out preventer (BOP) assembly in the formed borehole, the first activity including a slot formed in the work stand with a narrower width than that of the opening of the moon pool, wherein a first end of the slot is connected to the opening of the moon pool, a second end of the slot extends toward the bow side of the moon pool, a top side of the slot is opened to the platform, and a bottom side of the slot is opened to underwater; a rail installed under the platform in the moon pool of said stationary or floating structure; a BOP assembly including a BOP trolley moving on the rail while supporting the BOP assembly thereon and including wherein when the riser is positioned in the slot, the BOP assembly is supported by the BOP trolley which is place on the rail, and a middle portion of the riser is held by the slot, thereby suppressing shaking of the riser.