Abstract: A shallow water drilling barge (46) is supported on a silty water bed (50) of low bearing capacity by providing a submersible platform (74) such as the platform of a jackup drydock (40) with jacking legs (42), floating the jackup drydock into position, ballasting it until it rests on the bottom, floating the jackup drydock into position, ballasting it until it rests on the bottom, floating the drilling barge into position over the platform and floating the barge so that it comes to rest on the platform, with the weight of the barge and jackup drydock as so submerged being less than the load bearing capability of the underlying soil and then jacking down the legs of the jackup drydock to increase its load carrying capability.

Abstract: A shallow water drilling or production barge (46) is adapted for offshore use by means of a novel drydock (40) which has wing walls (52) of substantial freeboard and a platform (74) of essentially no freeboard. Jacking legs (42) extend down through the wingwalls to the sea bed (50). Valves (56) in the wing walls are opened to allow them to partially submerge and lower the platform enough to float the barge into place; and then jacking mechanisms in jacking towers (54) on the wing walls are operated to raise both the drydock and the barge up out of the water. The barge rides or rails 75 supported by roller assemblies on the platform; and after being raised the barge is pulled forwardly and locked in place.

Abstract: A self-contained jack up type drilling and production platform structure comprising a flotatable barge-like hull with support legs which can be jacked up and down to lower and raise the hull with respect to the surface of the sea. A removeable drilling module rests on top of the hull and extends over an opening therein between two of the support legs. Production equipment is arranged in the hull and communicates with the opening. Moveable conductor supports extend between the legs of the platform and serve to brace the drill string and production conduit conductors.