An apparatus for use in offshore oil or gas production in which a
plurality of vertical stabilizing columns are supported on a submerged
horizontal water entrapment plate is provided to support minimum offshore
oil and gas production facilities above a subsea wellhead, or subsea
processing facilities, or a submarine pipeline, and whose main function
is to provide power or chemicals or to perform other operations such as
compression, injection, or separation of water, oil and gas. The
apparatus is maintained in the desired location by a plurality of mooring
lines anchored to the sea-bed. The respective size and shape of the
columns and water entrapment plate are designed to provide sufficient
buoyancy to carry the weight of all equipment on the minimum floating
platform and mooring lines, umbilical and risers attached to it, and to
minimize the platform motion during normal operations.