What is single point mooring

Single point mooring system SPM (Single point mooring system) or Single buoy mooring (SBM), its main function is to locate the FPSO in the predetermined sea area, and it plays the role of transporting well flow, power, communication and other functions. At the same time, the FPSO has the effect of a wind vane, and the force of the FPSO is the smallest under the action of various winds, waves and currents, thus ensuring that the FPSO can work continuously at sea for a long time.

     Single point mooring comes from the English "Single Point Mooring". In short, compared with fixed docks, its biggest feature is that the mooring method is "point", that is, large oil tankers or very large oil tankers can be moored offshore A deep-water "spot" on the sea surface, where loading and unloading operations take place.

     A single point mooring terminal usually consists of a buoy that can float on the sea surface and a pipeline laid on the seabed to connect to the land storage system. The buoy floats on the sea surface. After the crude oil on the tanker enters the buoy through the floating hose, it enters the submarine pipeline from the underwater hose and is transported to the crude oil storage tank on the shore. In order to prevent the buoy from drifting with the waves for a long distance, several huge anchor chains are used to connect it to the seabed, so that the buoy can float and move with the wind, waves and current within a certain range, increase the buffering effect, and reduce the risk of collision with the giant ship , so as not to be drifted away by the waves.

     At present, this technology has been adopted by countries all over the world as a mature offshore transfer, warehousing and transfer technology.

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     First of all, a single point serves as a sea transfer terminal, through this "floating wharf", it can be used for mooring and loading and unloading crude oil or ore for large ships, giving full play to the advantages of large ship transportation. Secondly, as the oil production terminal of offshore oilfields, the single point plays the role of "floating oil depot", which is an economical and advanced means of storage and transportation in deep sea and remote oilfields. It can be said that the single point mooring technology has opened a new page in the history of offshore oil exploitation and maritime transportation, and has greatly promoted the development of offshore oil exploration and petrochemical industries. The rise, development and application of single point mooring technology have played an important role in the development of offshore oil and the improvement of sea transportation efficiency. As a technological revolution, what are the advantages of single-point mooring? Practice has proved that: First, the biggest advantage of single-point mooring is to move the wharf from the shore to the sea, which solves the problem of narrow and narrow waterways in most ports in the world. Shallow, small scale, can not match the contradictions of the development of large tankers and very large tankers. This has important practical significance in China's crude oil unloading, because among the hundreds of refineries in China, there are only two or three crude oil terminals capable of handling oil tankers with a capacity of more than 250,000 tons. Maoming Petrochemical in Maoming, Guangdong took the lead in introducing single-point technology, which is the first mobile terminal in mainland China. The single-point mooring technology has greatly increased Maoming Petrochemical's crude oil loading and unloading capacity, making Maoming Petrochemical's crude oil processing capacity break through the constraints of insufficient unloading capacity at the wharf. A new way for crude oil terminals with super large loading and unloading capacity. Secondly, the single-point mooring has the characteristics of floating and rotating: it can carry out crude oil loading and unloading under the condition of 7-level strong wind and effective wave height of 3.5 meters, and can freely rotate 360 degrees without restriction. , waves, and current changes, so it is less affected by the climate; while the general docking wharf, island type wharf, and trestle type wharf can only be unloaded in wind and waves below 2 meters, and are affected by environmental conditions (wind, wave, etc.) , flow) has a very large impact. The third is to save investment. Taking the Maoming 250,000-ton single-point mooring crude oil terminal as an example, the total construction investment is about 200-300 million yuan. Under normal circumstances, the construction of a fixed wharf of the same level requires at least 1 billion yuan, and the cost is about 3 to 4 times that of a single point mooring. Now take the United States as an example to illustrate the importance of single point mooring. As we all know, the United States handles more than 1 billion tons of crude oil every year. In 2002, the United States imported 9.14 million barrels of crude oil from abroad every day, of which more than 30%, that is to say, an average of more than 2.74 million barrels of imported crude oil per day, was imported through Louisiana. The three single point moorings of LOOP INC in New Orleans (New Orleans) with a coastline of about 30km were unloaded. The company's single point mooring is located at a water depth of 35 meters and is designed to berth the world's largest 700,000 dwt tanker. The crude oil received and unloaded by LOOP INC usually comes from the Middle East, West Africa, the North Sea, Colombia, Mexico and Alaska. about 500,000 tons). Without these three single-point moorings, these tankers would have to be transferred to small ships that can be docked at the transshipment facilities in the Caribbean, so the cost of transportation and transfer of imported crude oil is far from that of using single-point mooring for unloading. Refiners simply cannot afford it. It is also based on this consideration that 33 refineries in the eastern United States jointly funded the establishment of Lepu Company, and established a large-scale single-point mooring system including 3 single-point buoys, pipelines, and manifold structures through listing financing , to supply crude oil to each relevant refinery separately through interconnected onshore pipelines. It is a very wise choice and decision to concentrate advantages, give full play to the radiation effect, and make full use of the characteristics of single point mooring, which can avoid the great waste of resources caused by repeated construction. Take the eleven refineries in Louisiana and Texas, all of which are located in the Gulf of Mexico, it would not be impossible if they each built their own terminals, but the investment would be ten times larger. The first catenary anchor leg mooring (CALM) type single point mooring in the world was designed by the American IMODCO company (now renamed SBM-IMODCO company) for the Royal Swedish Navy in Dalarö, Sweden in 1958. built. This is a special-purpose system capable of mooring 3,000-ton ships. Since then, the application of single point mooring in the world has been unstoppable, and it has spread all over the coastal areas, which shows its vigorous vitality.