Abstract: Guide device for use in the processing, in particular welding, of curved surfaces, in particular pipe surfaces, comprising a flexible elongate body provided with a guide for processing means; tensioning means for tensioning the flexible body around the curved surface; wherein the flexible body is provided along its length with indicators arranged according to a determined pattern, this pattern being such that a determined position along the flexible body can be inferred on the basis of the detection of the indicators.

Abstract: Guide device for use in the processing, in particular welding, of curved surfaces, in particular pipe surfaces, comprising a flexible elongate body provided with a guide for processing means; tensioning means for tensioning the flexible body around the curved surface; wherein the flexible body is provided along its length with indicators arranged according to a determined pattern, this pattern being such that a determined position along the flexible body can be inferred on the basis of the detection of the indicators.

Abstract: Guide device for use in the processing, in particular welding, of curved surfaces, in particular pipe surfaces. A guide device includes a flexible elongate body provided with a guide for processing means and a tensioning means for tensioning the flexible body around the curved surface. The flexible body is provided along its length with indicators arranged according to a determined pattern, this pattern being such that a determined position of the guide device along the flexible body can be inferred on the basis of the detection of the indicators.

Abstract: A system for abandonment or recovery of a load, e.g., a pipeline or sub-sea structure, includes: at least two cables, each with a length adapted for a certain water depth and with a first end and a second end; a winch system for the at least two cables, the first ends of each cable being connected to the winch system; and a connection device for connecting the second ends of each cable to the load to be abandoned or recovered.

Abstract: A method and apparatus for welding together two pipes or plates. The bodies to be welded are placed mutually in line against each other while leaving clear a weld groove. The weld groove is filled with more than one welding layer by a welding torch moved in a longitudinal direction of the weld groove, and wherein two welding layers are laid in one welding pass by two welding torches placed successively at a predetermined fixed distance in the longitudinal direction of the weld groove, so that a time-saving is achieved in the welding process.

Abstract: A device for laying a pipeline on a seabed. A vessel for laying a pipeline, which is fitted with a stinger for guiding a pipe string descending from the vessel and with a clamping structure for clamping the pipe string to the vessel, and support structure for supporting the part of the pipe string that extends between the surface and the seabed. The support structure includes a cantilever structure, which is fixedly connected to the vessel, and clamping members that mate therewith. The clamping members engage the pipe string and transmit axial stresses from the pipe string to the vessel via the cantilever structure.

Abstract: A method and apparatus for connecting two pieces of pipe having flanges when the pipe pieces are located deep under a water surface. A movable bolt wrench is provided which has a number of wrenches mounted in a frame corresponding to the bolt holes on the flanges of the pipe pieces. Bolts located in the bolt wrenches are aligned with the bolt holes of the flanges and inserted into the bolt holes. A nut wrench is also provided containing nuts which, when aligned, are threaded onto the ends of the bolts associated with the bolt wrench. After the bolt and nut connections are made, these bolts and nuts are tightened by the operation of the bolt and nut wrenches.

Abstract: An apparatus for laying a pipeline (2) in water, comprising a vessel (1) with devices for assembling a pipeline from pipe parts, an elongate curved guide body (4) arrange on the hull of the vessel for guiding the pipeline from the vessel into the water, and a device (3) for carrying the guide body into respectively out of the water, wherein the elongate guide body is box-like, whereby a part of the forces exerted by the pipeline is absorbed by the guide track and the load on the hull is reduced.

Abstract: The invention relates to a method for assembling and disassembling an installation present on a seabed, for instance a pipeline lying on a seabed, wherein components, for instance pipe flanges, are mutually attached by means of nut and bolt connections and the nut and bolt connections are released and/or secured by means of a wrench. Nut and bolt connections are herein released by divers using a wrench. This is heavy and difficult work. It is impossible for divers to operate at considerable depth. Complicated and very costly pipeline connections are then applied which can be released and secured without divers. The invention has for its object to reduce the stated drawbacks of the known method. To this end at least one wrench is used, of which an engagement cup for engaging a nut and/or a bolt head in axial direction of a nut and bolt connection for manipulating is displaceable relative to a cup carrier counter to spring action.

Abstract: A device for lifting a sea-going structure (C), such as a drilling platform consisting of a superrstructure (B) and a jacket (J), which device consists of a flotation body (1) such as a boat provided with one or more laterally slidable lifting devices (2), wherein each lifting device (2) is provided with a coupling member (5) for fixing on a part of the substructure which is arranged for movement in all directions relative to the lifting device (2), whereby the device adapts better to the swell and the relative displacement of the flotation body (1) relative to the drilling platform.

Abstract: A method for lifting a sea platform with its substructure attached from a seabed and moving that platform to a different location. Use is made of flotation bodies which are filled with water and attached to the substructure. The flotation bodies can be emptied of some water to provide greater flotation and can be rotated around a horizontal axis to facilitate movement of the entire assembly under various sea conditions.

Abstract: An apparatus for processing curved surfaces, in particular a pipe surface, using processing means which are guided over that surface at a distance thereabove by means of a guide to be pre-arranged on that surface, wherein the guide consists of a flexible body provided with two parallel edges witch extend some distance above the surface for processing, and a carrier for the processing means is provided with a follower system consisting of at least three follower members which are ordered in a triangle and which co-act with the edges, this such that the carrier follows the curved surface at a fixed distance during movement along the guide, whereby processing of the surface can be performed under uniform conditions which enhances precision and therefore quality.

Abstract: A method for removing a superstructure from a jacket placed on a sea-bottom, wherein a vessel is positioned in the vicinity of the jacket. In this operation, the problem of the superstructure colliding with the jacket during lifting thereof due to up and down movement caused by the vessel floating on the waves is real and present. The superstructure and/or the jacket can sustain damage. To avoid such damage, the superstructure is engaged by lift supports which are movable relative to the vessel. Once the movement of the vessel in the waves is detected, lifting of the superstructure from the jacket is started when it is detected that the vessel is situated below it's average depth level in the sea.

Abstract: A method for laying a pipeline on a surface located under water such as a deep sea bed. The pipeline is held fixedly by tensioners having tensioning elements each extending between a clamping member engaging on the pipeline and a support member connected to a vessel. Tensioning is accomplished by sets of endless clamping bands which apply a braking action to the pipeline. A set of clamping jaws is clamped fixedly to the pipeline and moves along with the pipeline from a starting position to a releasing position. As a set of clamping jaws is clamped to the pipeline, another set of clamping jaws is released from the pipeline and returned to a starting position to continually repeat the cycle of holding and releasing of the pipeline.

Abstract: The invention provides a method for laying a pipeline on a floor located under water, wherein a pipe string is lowered from the pipe-bedding installation to the floor, characterized in that the part of the pipe string situated between the water surface and the floor is at least partially supported by bearing mechanism which engage on the pipe string, wherein an axial displacement is realized between the bearing mechanism on the one hand and the pipe string on the other.A heavy pipeline can hereby be laid on a deep seabed, for instance at a depth in the order of magnitude of 1-3 km, and/or the capacity of the draw benches on board the pipe-bedding installation can be reduced.

Abstract: The invention provides a method for laying a pipeline on a floor located under water, wherein a pipe string is lowered from the pipe-bedding installation to the floor, characterized in that the part of the pipe string situated between the water surface and the floor is at least partially supported by a bearing surface or trunk tubes which engage on the pipe string, wherein an axial displacement is realized between the bearing surface on the one hand and the pipe string on the other.A heavy pipeline can hereby be laid on a deep sea-bed, for instance at a depth in the order of magnitude of 1-3 km, and/or the capacity of the draw benches on board the pipe-bedding installation can be reduced.