SS-15® BIGBORE II™ SUBSEA WELLHEAD SYSTEM
Dril-Quip's SS-15 BigBore Subsea Wellhead Systems allow an additional casing string, casing hanger and seal assembly (typically 18") to pass through the 18-3/4" wellhead with the BOP stack and riser in place. This accommodates drilling and running large bore diameter casing string through pressurized water sands with complete BOP control and with all returns back to the drilling vessel. The illustration to the left shows a 36" x 26" x 22" x 18" x 16" x 13-5/8" x 9-7/8" casing program.

Rigid Lockdown System preloads wellhead connection together for high fatigue life

Special 18-3/4" Wellhead can safely pass 18" O.D. pipe with flush O.D. connections

18" intermediate casing string is drilled and set in a standard BOP controlled environment

22" adapter supplies landing shoulder and seal area for 18" and 16" Supplemental Casing Hanger Systems

All casing hangers and seal assemblies are run, set and tested on drill pipe in a single trip

Multiple conductor housings supply resistance to bending, are used to case off hazardous formations and accommodate complex casing programs

Available with Annulus Shutoff System to inhibit surface flow of water or hydrates

Easily accommodates casing programs with the Supplemental Casing Hanger Systems

Lockdown sleeve can be used to preload wellhead components in wellhead to inhibit thermal growth of casing strings

Incorporates all other features of the field-proven SS-15 Subsea Wellhead System