Abstract: A mobile sea barge having a unitary lower hull which has sufficient buoyancy to float the entire barge, an upper hull spaced from the lower hull by a single, centrally-positioned, vertical member, and a movable stabilizing hull arranged about the central support member for controlled movement between the upper and lower hulls is provided. Controlled movement of the stabilizing hull permits the operational modes of submerging and emerging of the lower hull into or from a bottom-founded gravity-forced mode from which drilling operations can be carried out. In the bottom-founded mode on the sea floor the barge functions as a gravity platform. Movement of the stabilizing hull is provided by a plurality of jacking legs and jacking units which constitute the control devices. The barge can be quickly switched between the surface-floating and the gravity-forced, bottom-founded modes. Controlled vertical descent to the sea floor is provided by the static stability of the stabilizing hull.

Abstract: A mobile sea barge having a unitary lower hull which has sufficient buoyancy to float the entire barge, an upper hull spaced from the lower hull by a single, centrally-positioned, vertical member, and a movable stabilizing hull arranged about the central support member for controlled movement between the upper and lower hulls is provided. Controlled movement of the stabilizing hull permits the operational modes of submerging and emerging of the lower hull into or from a bottom-founded gravity-forced mode from which drilling operations can be carried out. In the bottom-founded mode on the sea floor the barge functions as a gravity platform. Movement of the stabilizing hull is provided by a plurality of jacking legs and jacking units which constitute the control devices. The barge can be quickly switched between the surface-floating and the gravity-forced, bottom-founded modes. Controlled vertical descent to the sea floor is provided by the static stability of the stabilizing hull.

Abstract: An offshore system for laying a continuous length of pipe on the sea bottom from a pipe-carrying reel adapted to be mounted on a carrier vessel having an improved pipe handling and conditioning apparatus for working on the unspooled pipe. The improved apparatus includes a pipe straightener for imparting a reverse plastic bending moment to the unspooled pipe passing therethrough, and which comprises at least two pairs of pipe support rollers, each pair being aligned along the pipe path and mounted for rotational movement about respective rotational axes normal to the pipe path and parallel to the plane of the deck of the carrier vessel, and for pivoting movement about a pivot axis located between and substantially parallel to the respective rotational axes.