Marine Oil and Gas Development
Oil is the economic lifeline of a country. It is estimated that the recoverable oil resources are 300 billion tons, of which the offshore oil reserves are about 130 billion tons. The development of offshore oil began in the early 20th century. Its development has gone through a process from offshore to offshore, from shallow sea to deep sea. Limited by technical conditions and material development, only oil and natural gas deposits extending directly from the coast to the shallow sea can be exploited at first. Since the 1980s, stimulated by the energy crisis and technological progress, offshore oil exploration and development have developed rapidly, and offshore oil development has rapidly advanced to the continental shelf, gradually forming a new offshore oil industry sector. The offshore drilling platform is the working base for implementing offshore oil and gas exploration and exploitation, which marks the level of offshore oil and gas development technology. Offshore oil production equipment mainly includes oil production platforms and auxiliary equipment, and the auxiliary equipment includes crude oil coolers, oil risers, pumps, valves, joints and clamps. These equipment are in contact with seawater and sulfides, ammonia, chlorine and other media in crude oil. Because titanium has excellent corrosion resistance in these media, the United States used titanium offshore oil platform pillars in its oil fields in the early 1970s, and also used titanium to make shell-and-tube heat exchangers and plate heat exchangers. Titanium shell-and-tube heat exchangers use seawater as a cooling medium to cool the high-temperature gas/oil mixture extracted from the oil well. Titanium plate heat exchangers also use seawater as a cooling medium to cool the fresh water used to cool crude oil in carbon steel heat exchangers. The United States uses about 100 titanium heat exchangers on North Sea oil field drilling platforms. The titanium parts ordered by Hunting Oilfield Services in Aberdeen, Scotland, UK, are said to be the first titanium high-pressure riser shafts in the world, used in the Heidrum project of Continental Petroleum Company (Conoco) in Norway.
Petroleum titanium alloy titanium drilling pipes have a long service life, weigh only half of stainless steel, but are twice as flexible as stainless steel, and have a service life of 10 times that of steel. These excellent properties make titanium a material for drilling difficult, nearly circular, deep oil wells. The combined drilling tools containing titanium drill pipe can greatly reduce the drilling time and reduce the total drilling cost. GrantPrideco, RTI Energy Systems and Torch Drilling Services in the United States first used titanium drill pipe for industrial applications in 2000. The titanium drill pipe produced and supplied by GrantPrideco and RTI Energy Systems is also equipped with steel tool joints provided by GrantPrideco Anti-Fatigue. This joint is light in weight, flexible in use, and can make the titanium drill pipe strong and sturdy.
The seawater pipeline system is an indispensable part of offshore oil production. Since titanium has high corrosion resistance to seawater and its service life is 10 times that of steel, the cost of titanium alloy pipe system is cost-effective compared with Cu-Ni system. Active Metals of the United States and Precision Tube Technology have jointly established a titanium tube technology company to produce a large-diameter titanium alloy tube. The alloy used in this pipe is Ti-3Al-2.5V alloy, with a diameter of 650mm, a wall thickness of 22-25mm, a length of 350m, and a weight of 80-90t. It is planned to be used for offshore oil production. Another American company used a seamless titanium alloy tube with a length of 15m, an outer diameter of 600mm, and a wall thickness of 25mm to make a nearly 500m long vertical shaft pipe by extrusion, which has been used in an offshore drilling platform. It is said that the weight of this vertical shaft pipe can be halved, thereby greatly reducing the ballast cost. In addition, it also has high fracture toughness and long fatigue life.
According to data reports, in the North Sea oil field development project in the United States, the amount of titanium used in shipboard floating devices and seabed fixed devices has increased compared with before. The demand for titanium materials for 24 floating devices on board and 64 fixed devices on the seabed is: 50-100t for protection devices, 50-100t for connection devices, 400-1000t for general lifting equipment, and 1400-4200t for drill pipes. The corrosion of structural parts caused by biological contamination on offshore oil production platforms is quite serious. A US company uses long casing made of titanium tubes on the production platform to protect the parts on the platform.
In the past few years, the application of titanium alloy parts in oil drilling and coastal production operations has increased significantly. Titanium alloy parts allow oil drilling to enter deeper waters and deeper oil wells, including higher temperatures and severely corrosive (i.e., salty) production environments.
For such applications, considering the comprehensive performance, TC4 titanium rod (Ti-6Al-4V) based alloy is applicable and low cost. Seawater pipeline system is an indispensable part of offshore oil production. Since titanium has high corrosion resistance to seawater and its service life is 10 times that of steel, the cost of titanium pipe system is cost-effective compared with Cu-Ni system. Active Metals Company of the United States and Precision Tube Technology Company jointly established a titanium pipe technology company to produce a large-diameter titanium alloy pipe. The alloy used in this pipe is TA18 (Ti-3Al-2.5V) alloy, with a diameter of 650mm, a wall thickness of 22-25mm, a length of 350m, and a pipe weighing 80-90t. It is planned to be used for offshore oil production. Another American company used a seamless titanium alloy pipe with a length of 15m, an outer diameter of 600mm, and a wall thickness of 25mm to make a nearly 500m long vertical shaft pipe by extrusion, which has been used in an offshore drilling platform. It is said that the weight of this vertical shaft pipe can be halved, thereby greatly reducing the ballast cost. In addition, it also has high fracture toughness and long fatigue life.
Practice has proved that Ti-6Al-4V (Gr.5_TC4) alloy is the best material for drilling pipes. As a drilling application, yield strength and fatigue strength are important. Therefore, two Gr.5 alloys with particularly low interstitial elements are suitable for more critical dynamic lifting devices. When the operating temperature exceeds 75-80°C, in order to prevent crevice corrosion or stress corrosion, ruthenium-containing Gr29 alloy is used. Commonly used components include coastal drilling lifting devices, drilling pipes, tapered stress joints (TSJs) and titanium/steel mixed lifting devices.
Small titanium parts such as titanium pumps, valves, joints, fasteners, fixtures and spare parts have been widely used on oil production platforms. Titanium alloys are also widely used in the shells of foreign offshore oil exploration and well detection instruments.
Harbor construction
The titanium material has an oxide film with a thickness of no more than 10nm on its surface. It is very stable in a corrosive environment and has excellent corrosion resistance to air, seawater and marine environment. It is currently a raw material that can adapt to various marine environments. Japan has vigorously developed the ocean, such as the bridge from Honshu to Shikoku, the Tokyo Bay Crossing Road, Kansai Airport, and the floating oil storage base. The exposure test conducted by the Japanese Ministry of Construction and the Steel Club on the Oi River and the various anti-corrosion exposure tests conducted by the Ministry of Transport and the Steel Pipe Pile Association on the Hasaki Drifting Sand Pier also show that titanium is a suitable material. In addition to its excellent anti-corrosion performance, titanium also has the advantages of very few dissolved ions in seawater environments, and no need to worry about environmental pollution. Japan has also built a super-large floating marine structure, using titanium-steel composite materials in seawater scouring areas; in the construction of the Tokyo Bay Crossing Road, titanium materials were used as splash-proof trunks for bridge piers, and the amount of titanium used for each bridge pier is 0.9t. Large floating marine buildings that have been used or are planned include airports, port logistics bases, sports facilities, etc.
Coastal power station
The comprehensive utilization of seawater is one of the important projects in marine engineering. The condenser of coastal power station is a device that uses a large amount of seawater. Titanium used in coastal power stations is mainly used in condensers. Since the condenser uses seawater as cooling water, and seawater contains a large amount of mud, suspended matter, marine organisms and various corrosive substances, the situation is more serious in the fresh salt water where seawater and river water alternate. Traditional condensers use copper alloy tubes, which are often severely damaged due to various corrosion in seawater. Titanium has good corrosion resistance in seawater, especially in polluted seawater, and its high-speed erosion and corrosion resistance to seawater is particularly outstanding.
Seawater desalination device
"Water is the source of life." At present, the lack of water resources has become a problem that plagues the world. About 25% of the world's population does not have sufficient drinking water resources. The land rivers and groundwater resources in the world are far from meeting the needs of industrial development. Therefore, in the future, seawater desalination will be an effective way for humans to solve freshwater resources.
