Subsea wellhead systems
Subsea wellhead systems The subsea wellhead system ( Fig. 1 ) is a pressure-containing vessel that provides a means to hang off and seal off casing used in drilling the well. The wellhead also provides a profile to latch the subsea blowout preventer (BOP) stack and drilling riser back to the floating drilling rig. In this way, access to the wellbore is secure in a pressure-controlled environment. The subsea wellhead system is located on the ocean floor, and must be installed remotely with running tools and drillpipe. Fig. 1—Illustration of a typical subsea wellhead system with temporary abandonment cap installed. This illustration also shows the wellhead configuration with a 30 × 20 × 13⅜ × 9⅝ × 7-in. casing program. Subsea wellhead system The subsea wellhead inside diameter (ID) is designed with a landing shoulder located in the bottom section of the wellhead body. Subsequent casing hangers land on the previous casing hanger installed. Casing is suspended from each casing-hange...