Month: July 2009

A floating vessel that is supported primarily on large pontoon-like structures submerged below the sea surface. The operating decks are elevated 100 or more feet above the pontoons on large steel columns. This design has the advantage of submerging most of the area of components in contact with the sea and minimizing loading from waves and wind. Semisubmersibles can operate in a wide range of water depths, including deep water. They are usually anchored with six to twelve anchors tethered by strong chains and wire cables, which are computer controlled to maintain station keeping. The semi-submersibles present less surface area to waves and so are less susceptible to pitch and roll motions but are still subject to heave motions and are not designed to store large quantities of oil.

Such as hydrocarbons that are in a semisolid state

Such as natural gas storage facility used for self consumption (which according to the Gas Law does not require a license), or an IPP generating electricity for the self consumption of its owners rather than for sale to the grid or to end consumers. Could also relate to the consumption required by the station itself within the process of generating electricity

The study of seismic waves

Are geophysical information on subsurface rock formations gathered by means of a seismograph; the investigation of underground strata by recording and analyzing shock waves artificially produced and reflected from the subsurface bodies of the rock