SS-20 and SS-15 BigBore II-H

The BigBore II-H series Subsea Wellhead Systems are Dril-Quip’s next generation wellhead system designed for deepwater, deep well applications. The BigBore II-H System features higher load carrying capacity and higher temperature ratings. It has been designed to facilitate the drilling of wells that penetrate shallow water flow zones and require several casing strings to accommodate small pore pressure/fracture-gradient differentials.


The BigBore II-H Subsea Wellhead System allows an additional 18" casing string, hanger and seal assembly to pass through the 18-3/4" wellhead with the BOP stack and riser in place. This accommodates drilling and running a large bore diameter casing string through shallow pressurized water sands with complete BOP control and with drilling returns back to the drilling vessel.


SS-20 BigBore II H Wellhead

System Features:

  • All 18-3/4" BigBore II-H components certified to API 17D 2nd Edition and 6A specifications
  • SS-20 Wellhead housing designed for 20,000 psi and 8.8 million lbs of end-load carrying capacity, a nominal 30" O.D. and a 350°F temperature rating
  • SS-15 Wellhead housing designed for 15,000 psi and 8.8 million lbs of end-load carrying capacity, a nominal 27" O.D. and a 300°F temperature rating
  • High-tensile, high-bending, high-load and high-pressure capacity
  • Incorporates ROV-assisted annulus shut-off monitoring system
  • Utilizes two 22" adapters for landing 18" and 16" supplemental casing hanger systems
  • Wellhead can pass 18" and 16" casing, casing hangers and testable/retrievable/replaceable seal assemblies inside standard 21" O.D. riser and 18-3/4" BOP stack
  • All casing hangers and seal assemblies are run, set and tested on drill pipe in a single trip
  • Two million lbs preloaded rigid lockdown wellhead system
  • Utilizes Dril-Quip’s reliable high-temperature, weight-set metal-to-metal seal assembly
  • Large cement return flow-by areas on all casing hanger systems
  • Bit-runnable wear sleeves and wear bushings available
  • Alternative casing programs available


Contact your Dril-Quip representative for more information about the SS-20 and SS-15 BigBore II-H Subsea Wellhead Systems.