For those who encounter unfamiliar terms in this article, HPC compiled the following definitions:
Carcass profile: The carcass prevents collapse of the pipe liner as a result of gas expansion or hydrostatic pressure.
Choke and kill: Pipelines used to reduce or stop pressure from the well as part of a deepwater blowout-preventer system.
Counter-current decantation vessels: A series of settling vessels in which solids can be treated continuously and diluted.
Downlines: Used to convey nonhazardous fluids (i.e., water, air, nitrogen) to the seabed for temporary applications, such as pipeline commissioning/precommissioning and/or servicing or seabed excavation.
Electrowinning: The electrodeposition of metals from their ores.
Fracking: Slang for hydraulic fracturing, in which fluid is injected into cracks to create fractures in rocks and rock formations that allow greater access to gas in shale formations.
Hydrometallurgy: Any method for obtaining metals from a solution (liquid).
Intervention or work-over: any operation carried out on an oil or gas well during or at the end of its production life.
Jumpers: Pipes that carry fluids from each subsea tree (well) to the manifold; also can connect manifolds and riser bases to flowlines.
Launder: A trough for holding or conveying water used to wash ore.
Plug and abandonment: Interrupting the pressure from the well and then plugging the wellhead.
Rare-earth element: Any group of chemically similar metallic elements. Although not especially rare, they tend to occur together in nature and are difficult to separate from one another.
Riser: Rigid or flexible conduit used to transfer materials (i.e., hydrocarbons, injection fluids, control fluids, etc.) from the seafloor to surface production and drilling facilities.
Subsea tree: A tree-shaped device (hence, the name) attached to a subsea wellhead. It monitors/controls the operation of a subsea well.
Sour service: Describes the function of pipelines that handle fluids or gases that contain hydrogen sulfide.
Top tension: The tension required to stabilize a riser system. On offshore drilling vessels or platforms, riser tensioners are complex hydro-pneumatic systems that, simply put, pull up on the riser string. The heavier the riser string, the greater is the top tension required to support it.
This short article is a sidebar to a feature aritcle titled "Fossil and mineral resources: Composites expand. To read the main article, click on its title under "Editor's Picks," at top rgiht.