A disclosed subsea sediment separation and filtration system includes first and second separation devices, a spreader apparatus, and a storage device. The first separation device receives a water/sediment/oil mixture and from a subsea surface and separates the mixture into a first component containing cleaned sediment and a second component containing a water/oil mixture. The spreader apparatus disperses the cleaned sediment of the first component into a subsea environment of the spreader apparatus. The second separation device receives the second component from the first separation device and separates the second component into a cleaned water component and an oil component. The second separation device disperses the cleaned water component into a subsea environment of the second separation device and provides the oil component to the storage device. The first separation device may include a plurality of hydrocyclone devices, and the second separation device may include a high pressure hydrocyclone device.

A disclosed subsea sediment separation and filtration system includes first and second separation devices, a spreader apparatus, and a storage device. The first separation device receives a water/sediment/oil mixture and from a subsea surface and separates the mixture into a first component containing cleaned sediment and a second component containing a water/oil mixture. The spreader apparatus disperses the cleaned sediment of the first component into a subsea environment of the spreader apparatus. The second separation device receives the second component from the first separation device and separates the second component into a cleaned water component and an oil component. The second separation device disperses the cleaned water component into a subsea environment of the second separation device and provides the oil component to the storage device. The first separation device may include a plurality of hydrocyclone devices, and the second separation device may include a high pressure hydrocyclone device.

A system for assembling a cofferdam. In a first example embodiment, a cofferdam may be assembled on-site using a plurality of walls that couple each other to form the cofferdam. In a second example embodiment, a plurality of walls and a plurality of connectors may be assembled to form the cofferdam. The walls and/or connectors disassembled for transport and/or storage, yet quickly assembled on-site to form the cofferdam. The panels and/or the connectors may form cofferdams of various shapes and sizes. The walls and/or connectors are made of a durable material that permits multiple uses. The cofferdam may be assembled to hold back the water of a body of water from around a culvert while work or repairs are performed.

A system for assembling a cofferdam. In a first example embodiment, a cofferdam may be assembled on-site using a plurality of walls that couple each other to form the cofferdam. In a second example embodiment, a plurality of walls and a plurality of connectors may be assembled to form the cofferdam. The walls and/or connectors disassembled for transport and/or storage, yet quickly assembled on-site to form the cofferdam. The panels and/or the connectors may form cofferdams of various shapes and sizes. The walls and/or connectors are made of a durable material that permits multiple uses. The cofferdam may be assembled to hold back the water of a body of water from around a culvert while work or repairs are performed.

A disclosed subsea sediment separation and filtration system includes first and second separation devices, a spreader apparatus, and a storage device. The first separation device receives a water/sediment/oil mixture and from a subsea surface and separates the mixture into a first component containing cleaned sediment and a second component containing a water/oil mixture. The spreader apparatus disperses the cleaned sediment of the first component into a subsea environment of the spreader apparatus. The second separation device receives the second component from the first separation device and separates the second component into a cleaned water component and an oil component. The second separation device disperses the cleaned water component into a subsea environment of the second separation device and provides the oil component to the storage device. The first separation device may include a plurality of hydrocyclone devices, and the second separation device may include a high pressure hydrocyclone device.

A cofferdam is disclosed that includes an open frame structure having double walls defining a hollow space within each double wall, with each double wall having an open bottom end and a closed top end. Each of the double walls are configured to act as suction piles allowing liquid to be removed from the space within each double wall to thereby induce negative pressure when the cofferdam is installed in a sub-sea configuration. Each of the double walls may include a plurality of partitions respectively defining a plurality of suction piles, the suction piles fluidically coupled by a manifold that may allow liquid to be removed from the suction pile to thereby drive the cofferdam structure into the subsea surface due to the induced negative pressure. A further embodiment cofferdam structure includes an open frame structure and one or more suction piles attached to the open frame structure.

An enclosure having a bottom plate, a wall, and an opening to pass a portion of a pier into the enclosure. A first sealing member coupled to the bottom plate. Watertight tanks coupled to the enclosure float the enclosure in a body of water, at a position above a footing of the pier with the portion of the pier in the enclosure, sink the enclosure to compress the first sealing member between the bottom plate and a ledge of the footing, and re-float the enclosure. A method includes floating and navigating the enclosure to the position and adding weight to sink the enclosure. A plurality of adjustable length structures may be lengthened to exert a downward force on the bottom plate to secure it to the ledge. A second sealing member may be forced into the opening between the pier and wall of the enclosure to facilitate dewatering the enclosure.

An enclosure having a bottom plate, a wall, and an opening to pass a portion of a pier into the enclosure. A first sealing member coupled to the bottom plate. Watertight tanks coupled to the enclosure float the enclosure in a body of water, at a position above a footing of the pier with the portion of the pier in the enclosure, sink the enclosure to compress the first sealing member between the bottom plate and a ledge of the footing, and re-float the enclosure. A method includes floating and navigating the enclosure to the position and adding weight to sink the enclosure. A plurality of adjustable length structures may be lengthened to exert a downward force on the bottom plate to secure it to the ledge. A second sealing member may be forced into the opening between the pier and wall of the enclosure to facilitate dewatering the enclosure.

A deployable cofferdam web-supporting frame assembly for a cofferdam system configured to be installed within a body of water to at least partially delimit therein an enclosure. The deployable cofferdam web-supporting frame assembly comprises first and second frame-supporting structures comprising first and second apexes and first and second groups of longitudinally extending frame-supporting legs each having a waterbed-engaging end, the first and second frame-supporting structure being configurable into a usage configuration wherein the frame-supporting legs are connected to each other with the waterbed-engaging ends thereof being spaced apart from one another, and a storage configuration wherein the frame-supporting legs are substantially parallel to each other; and a connecting assembly connecting the first and second apexes to each other. It also concerns a cofferdam system comprising the same and a corresponding method for delimiting an enclosure within a body of water.