초록 ▼

An oil storage, loading and offloading system includes a submerged oil storage tank with multiple vertically placed flexible containers. The system directly connects to the topsides of an offshore oil production platform above water to assist oil loading and offloading operations. During loading, oi

An oil storage, loading and offloading system includes a submerged oil storage tank with multiple vertically placed flexible containers. The system directly connects to the topsides of an offshore oil production platform above water to assist oil loading and offloading operations. During loading, oil is pumped in and stored inside flexible containers, which are expanded to displace equivalent amount of water out of the oil storage tank; during offloading, oil is pumped out from flexible containers and the reduced volume of each contracted container is then filled in by the equivalent amount of water from the surroundings There is no physical contact between water and oil. The submerged tank on-bottom weight has a limited variation during the loading and offloading operations. This disclosed system can be utilized for fixed offshore platforms, especially for shallow water marginal field developments, and for deepwater floating platforms such as SPAR and semi-submersible (SEMI) structures.

대표청구항 ▼

1. A submerged oil storage and off-take system for a fixed offshore platform, comprising: a topsides for oil production positioned above water surface;an underwater storage tank for oil and water storage, with a preset minimum submerged distance between the water surface and the top of the tank, con

1. A submerged oil storage and off-take system for a fixed offshore platform, comprising: a topsides for oil production positioned above water surface;an underwater storage tank for oil and water storage, with a preset minimum submerged distance between the water surface and the top of the tank, connected to the topsides with a plurality of leg members, wherein the storage tank comprises a plurality of non-sealed vertical compartments, each vertical compartment houses one vertically placed flexible container for oil storage, with the remaining room of the compartment for water storage, without any physical contact between oil and water, the flexible container is fixed with the vertical compartment both at top and at bottom;a pre-installed foundation between seabed and the bottom of the storage tank to provide a support for the storage tank, the foundation connected with the seabed with a plurality of fixings, and the foundation to be installed prior to the arrival of the storage tank; anda plurality of grouped communication channels connected at one end with each flexible container and at the other end with the topsides above the water surface; at least one fluid channel with one end positioned outside the tank to interface with surrounding water and with the other end positioned inside the tank. 2. The submerged oil storage and off-take system according to claim 1, wherein the vertical compartment has a polygonal cross-section shape. 3. The submerged oil storage and off-take system according to claim 1, wherein the pre-installed foundation is a truss structure with a height between the bottom of the storage tank and the seabed. 4. The submerged oil storage and off-take system according to claim 1, wherein the plurality of fixings connecting the foundation to the seabed are either suction piles or foundation piles. 5. The submerged oil storage and off-take system according to claim 4, wherein the distance between a front fixing and a rear fixing is larger than the water depth at the site. 6. The submerged oil storage and off-take system according to claim 3, wherein the height of the truss structure between the bottom of the storage tank and the seabed is taller than 2 meters. 7. The submerged oil storage and off-take system according to claim 1, wherein the preset minimum submerged distance is larger than half of the maximum wave height that the platform could ever encounter during a service life of the platform. 8. The submerged oil storage and off-take system according to claim 1, wherein the grouped communication channels comprise a) a hot liquid circulation system,b) an oil loading and offloading system,c) an air injection and release system, andd) a system for placing sensors. 9. The submerged oil storage and off-take system according to claim 1, wherein the flexible container is a rubber bag composed of a plurality of layers: a) a top layer composed of a plurality of sub-layers with rubber material and a plurality of fiber nets bonded together through vulcanization,b) a thermal insulation layer with thermal insulation materials,c) an air sealing layer composed of a thin rubber sheet or a sheet made of synthetic materials, and,d) a chemical protection layer composed of a thin sheet with anti-chemical corrosion property, which could be glued to the inner surface of the air sealing layer. 10. A drilling and oil production platform equipped with a submerged oil storage and off-take system for a shallow water field development, comprising: a pre-installed wellhead platform to be installed prior to the arrival of a combined system having an oil storage tank and a topsides connected together in a vertical orientation, wherein the wellhead platform comprises — an adjustable support foundation with a deck above water and a plurality of well conductor guides for drilling purpose,a plurality of supporting pads at the top of the adjustable support foundation for supporting the combined system,a plurality of fixings at the bottom of the adjustable support foundation connecting the adjustable support foundation to seabed, anda docking fender installed on the adjustable support foundation and a plurality of vertical posts having fixed bottoms on the adjustable support foundation for vertical docking and lowering operations of the combined system;the combined system with the oil storage tank docked on the adjustable support foundation of the wellhead platform, wherein the oil storage tank comprises a plurality of non-sealed vertical compartments, each vertical compartment houses one vertically placed flexible container for oil storage, with remaining room for water storage, without any physical contact between oil and water, each flexible container is fixed with the vertical compartment both at top and at bottom;a plurality of sleeves installed at the storage tank outer surface for the tank vertical docking and lowering purpose;a plurality of grouped communication channels connected at one end with each flexible container and at the other end with the topsides above water surface; andat least one fluid channel with one end positioned outside the tank to interface with surrounding water and with the other end positioned inside the tank;wherein the pre-installed wellhead platform and the combined system are integrated through a set of installation procedures without a need for use of a crane vessel or a transport vessel, the set of installation procedures comprise — a) transportation—the storage tank functioning as a transportation vessel for the transportation of the combined system in a vertical orientation, having a plurality of the flexible containers full of injected air as individual intact compartments to provide the damaged stability of the tank during the transportation,b) site vertical docking—utilizing tugs for alignment of each pair of the sleeve and the post, and utilizing ballasting to the tank and the air releasing from selective flexible containers during the vertical docking, andc) lowering and integration—continuing the ballasting and air releasing actions to lower the tank onto the support foundation until the completion of the integration between the pre-installed wellhead platform and the combined system. 11. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 10, wherein the vertical compartment has a polygonal cross-section shape. 12. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 10, wherein the adjustable support foundation is a truss structure between the bottom of the storage tank and the seabed, and the support foundation is adjustable after the platform ceases service at one site location, and then the truss structure can be modified for another site application with different water depth and different soil condition. 13. The drilling and oil production and oil storage platform equipped with a submerged oil storage and off-take system according to claim 10, wherein the plurality of fixings connecting the support foundation to the seabed are either suction piles or foundation piles. 14. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 13, wherein the distance between a front fixing and a rear fixing is larger than the water depth at the site. 15. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 12, wherein the height of the truss structure beneath the tank is larger than 2 meters. 16. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 10, wherein at least one vertical post top is above water surface. 17. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 10, wherein the wellhead platform is a self-installable structure without a need for use of a transport vessel or a crane vessel during an installation. 18. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 10, wherein the combined system is a self-installable structure without a need for use of a transport vessel or a crane vessel during an installation. 19. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 10, wherein the grouped communication channels comprise — a) a hot liquid circulation system,b) an oil loading and offloading system,c) an air injection and release system, andd) a system for placing sensors. 20. The drilling and oil production platform equipped with a submerged oil storage and off-take system according to claim 10, wherein the flexible container is a rubber bag composed of a plurality of layers: a) a top layer composed of a plurality of sub-layers with rubber material and a plurality of fiber nets bonded together through vulcanization,b) a thermal insulation layer with thermal insulation material,c) an air sealing layer composed of a thin rubber sheet or a sheet made of synthetic materials, and,d) a chemical protection layer composed of a thin sheet with anti-chemical corrosion property, which could be glued to the inner surface of the air sealing layer. 21. A submerged oil storage and off-take system, comprising: a submerged storage tank coupled with a topsides above water surface, with a preset minimum submerged distance between the water surface and top of the tank, for storing oil and water together, the storage tank, having an one-way flow channel equipped with a check valve to stop free exchange passage between water inside the tank and surrounding water, comprises a plurality of non-sealed vertical compartments, each vertical compartment comprises one vertically placed flexible container for oil storage and a remaining room of the compartment for water storage, with no physical contact between oil and water inside the compartment, the flexible container is fixed with the vertical compartment both at top and at bottom;a plurality of grouped communication channels having one end inside one of the plurality of flexible containers and the other end at the topsides above the water surface for oil loading and offloading purpose;different fluid channels with one end positioned inside the tank and the other end positioned outside the tank, utilized for the water inside the tank communicating in one-way flow with the surrounding water during oil loading and oil offloading operations, wherein a) during oil loading operations, displaced water inside the tank is pumped to a water monitoring/processing vessel at the topsides to ensure water's cleanness before being discharged to the surrounding water, andb) during oil offloading operations, a fluid channel equipped with a check valve to only allow the surrounding water to have a one-way flow into the tank; anda foundation beneath the storage tank to keep the bottom of the storage tank off seabed with a height between the seabed and bottom of the storage tank. 22. The submerged oil storage and off-take system according to claim 21, wherein the vertical compartments have a polygonal (hexagon, octagon, etc.) cross-section shape. 23. The submerged oil storage and off-take system according to claim 21, wherein the flexible container is a rubber bag composed of a plurality of layers. 24. The submerged oil storage and off-take system according to claim 21, wherein the preset minimum submerged distance is larger than half of the maximum wave height (Hmax) that the platform could ever encounter during its service life. 25. The submerged oil storage and off-take system according to claim 21, wherein the foundation is seabed. 26. The submerged oil storage and off-take system according to claim 21, wherein the grouped communication channels comprise a) a hot liquid circulation system,b) an oil loading and offloading system,c) an air injection and release system, andd) a system for placing sensors. 27. The submerged oil storage and off-take system according to claim 21, wherein the flexible container is a rubber bag composed of a plurality of layers: a) a top layer composed of a plurality of sub-layers with rubber material and a plurality of fiber nets bonded together through vulcanization,b) a thermal insulation layer with thermal insulation materials,c) an air sealing layer composed of a thin rubber sheet or a sheet made of synthetic materials, and,d) a chemical protection layer composed of a thin sheet with anti-chemical corrosion property, which could be glued to the inner surface of the air sealing layer.