Semisubmersible

A floating vessel, platform or rig. Ballast tanks within submerged pontoon columns are filled with water, enabling the structure to achieve stability when anchored on-site.

Slips

Metal gripping elements which hold the drill pipe in place.

SPE

Society of Petroleum Engineers

Spider

A set of slips which support the riser when it is being run or retrieved, or while connections are being made or broken.

Spool

A short section of rigid pipe with flanges or connections at each end. Created to the exact length required for make-up, spools are commonly used to connect flowlines and or subsea facilities together.

Stick Slip

A sudden jump in velocity from standstill as a reaction to built-up torsional energy along the length of the drill string. While ‘stuck’, the bit stops drilling but torque continues to be applied from the turning rotatory table on the rig floor. The build-up of torque causes the bit to giveaway and ‘slip’, resulting in a significant increase in rotational speed. Vibrations are sent along the drill string, which can cause damage.

Syntactic Foam

A composite material consisting of a polymer matrix containing hollow particles or microspheres.