Abstract: A structure such as a pipeline bundle is pulled into or through shallow water, for example when launching the structure, by applying a tensile pulling force to the structure through rigging that extends to the structure from a winch of a first vessel. The pulling force is at least partially reacted through a pennant line that extends from the first vessel to a second vessel and that hangs between the first and second vessels to engage the seabed soil frictionally. The vessels may also self-propel to contribute their thrust to the pulling force. The pennant line includes a clump weight such as a bundle of chains that can be repositioned easily for additional pulls by being lifted between the vessels before being lowered to the seabed at a new location.

Abstract: A method of dewatering a subsea pipeline bundle assembly before lifting the assembly from the seabed comprises adding discrete buoyancy to an elongate carrier pipe of the assembly. The buoyancy elevates one or more portions of the carrier pipe disposed between drainage outlets of the assembly. Each elevated portion defines inclined falls that slope downwardly in opposed longitudinal directions toward the respective outlets. Water within the carrier pipe drains down the falls toward the outlets. Injecting a dewatering fluid into the carrier pipe promotes expulsion of water from the pipe through the outlets by downward displacement of the water. Drainage can be assisted by a venturi effect driven by accelerating the flow of the dewatering fluid at a location in line with an outlet.

Abstract: A method of installing a production buoy at a subsea anchoring location is disclosed. The method includes floating a production buoy over a subsea anchoring location. Then, hanging at least a tether off the production buoy such that the or each tether extends from the production buoy towards the subsea anchoring location occurs. The method includes submerging the production buoy to a depth which allows connection of the or each tether to the subsea anchoring location. An apparatus suitable for use with this method is also provided.

Abstract: There is provided a method and apparatus for lowering and/or raising a load or structure to or from the bed of a body of water. The apparatus comprises a buoyancy apparatus configured to be coupled to a load, and having positive buoyancy sufficient to lift the load. At least one receptacle is provided on the apparatus for receiving a control weight lowered from a vessel to lower or raise the assembly. The lowering method includes forming an assembly from a buoyancy apparatus and a load and submerging the assembly to a position at a first height above the bed. In a preferred embodiment the assembly is submerged by a clump weight tow system. A control weight is deployed from a vessel to the assembly to overcome the positive buoyancy of the assembly and thereby lower the load from the first height to the bed. The raising method reverses the steps of the lowering method.

Abstract: There is provided a method and apparatus for lowering and/or raising a load or structure to or from the bed of a body of water. The apparatus comprises a buoyancy apparatus configured to be coupled to a load, and having positive buoyancy sufficient to lift the load. At least one receptacle is provided on the apparatus for receiving a control weight lowered from a vessel to lower or raise the assembly. The lowering method includes forming an assembly from a buoyancy apparatus and a load and submerging the assembly to a position at a first height above the bed. In a preferred embodiment the assembly is submerged by a clump weight tow system. A control weight is deployed from a vessel to the assembly to overcome the positive buoyancy of the assembly and thereby lower the load from the first height to the bed. The raising method reverses the steps of the lowering method.

Abstract: A method of installing a production buoy at a subsea anchoring location is disclosed. The method includes floating a production buoy over a subsea anchoring location. Then, hanging at least a tether off the production buoy such that the or each tether extends from the production buoy towards the subsea anchoring location occurs. The method includes submerging the production buoy to a depth which allows connection of the or each tether to the subsea anchoring location. An apparatus suitable for use with this method is also provided.

Abstract: A riser configuration having a rigid riser portion and a flexible riser portion. The riser configuration also includes a subsea buoy across which the riser portions are connected. Buoyancy means are mounted on the flexible riser portion.

Abstract: A method of installing a production buoy at a subsea anchoring location is disclosed. The method includes floating a production buoy over a subsea anchoring location. Then, hanging at least a tether off the production buoy such that the or each tether extends from the production buoy towards the subsea anchoring location occurs. The method includes submerging the production buoy to a depth which allows connection of the or each tether to the subsea anchoring location. An apparatus suitable for use with this method is also provided.

Abstract: A riser configuration having a rigid riser portion and a flexible riser portion. The riser configuration also includes a subsea buoy across which the riser portions are connected. Buoyancy means are mounted on the flexible riser portion.

Abstract: A method of installing a production buoy at a subsea anchoring location is disclosed. The method includes floating a production buoy over a subsea anchoring location. Then, hanging at least a tether off the production buoy such that the or each tether extends from the production buoy towards the subsea anchoring location occurs. The method includes submerging the production buoy to a depth which allows connection of the or each tether to the subsea anchoring location. An apparatus suitable for use with this method is also provided.

Abstract: There is provided a method and apparatus for lowering and/or raising a load or structure to or from the bed of a body of water. The apparatus comprises a buoyancy apparatus configured to be coupled to a load, and having positive buoyancy sufficient to lift the load. At least one receptacle is provided on the apparatus for receiving a control weight lowered from a vessel to lower or raise the assembly. The lowering method includes forming an assembly from a buoyancy apparatus and a load and submerging the assembly to a position at a first height above the bed. In a preferred embodiment the assembly is submerged by a clump weight tow system. A control weight is deployed from a vessel to the assembly to overcome the positive buoyancy of the assembly and thereby lower the load from the first height to the bed. The raising method reverses the steps of the lowering method.