The application of
titanium in offshore engineering can be used in the engineering fields of offshore oil and gas exploitation, including offshore platform structures and offshore engineering facilities used to detect hydrocarbons, extract petroleum and transport hydrocarbon raw materials from oil and gas fields.
Titanium alloys can be used in a variety of petroleum production systems and equipment. Marine underwater equipment includes: drill pipe, underwater riser, fuselage and other components of deep-submersible engineering equipment; Marine equipment (platforms) include seawater and drinking water systems, various heat exchange equipment (distillers, steam generators, condensers), pumps, fire fighting systems, and other components. In Europe, Norway and Britain have the most thorough research on offshore exploitation of titanium alloy. Oil RIGS in the Norwegian sea, for example, are known to use a lot of titanium alloys, each with a total of more than 500t.
Russia rarely USES titanium alloys in its offshore drilling, but it has also recently begun aggressively drilling for oil and gas in the Arctic Circle and the far east trench.
Russia and Norway have forged a strategic partnership to exploit oil and gas in the arctic. Norway has become a strategic partner in Russia's plans to develop arctic oil and gas. Therefore, it is believed that titanium alloys can be more widely used in arctic oil and gas exploration.
In the design of the Pryrazlomnoje oil and gas field platform located in the Arctic Circle, it is proposed to use titanium alloy 350~400t pipeline network, in which part of the pipeline surface is treated with thermal oxidation to protect the steel structure of the platform from galvanic corrosion.
With the development of offshore oil industry, more titanium alloys are needed to manufacture machinery, so the demand for titanium alloys will increase rapidly. Extracting oil and gas, especially in the deeper parts of the ocean, will make titanium and titanium alloys increasingly important, because drilling at great depths means reducing the quality of drilling systems. For heavy-duty steel drilling systems, the platform base needs to be stronger and the lifting equipment more powerful than titanium equipment.
Fracture length refers to the length of a pipe that may break under its own gravity. As can be seen from figure 1, at the same yield strength, the fracture length of titanium pipe is much larger than that of iron pipe. This means that titanium piping systems can be used in deeper oil and gas fields than iron piping systems at the same weight.
There are also advantages to using titanium as a replacement structure for drilling. Using titanium in risers, for example, could reduce structural density, increase buoyancy, and even allow submersibles to operate deeper.
The problem of hydrocarbon exploitation increases with the increase of ocean depth and oil and gas reservoir depth. The Russian Shtokmanovskoje condensate field in the Baltic sea has a depth of 280 to 380m, while the condensate reservoirs are at a depth of 1,800 to 2,300 m.
As drilling operations need to be carried out in harsh geological conditions, the requirements of contrast strength, thermal conductivity and wear resistance will be more severe.
The titanium alloy materials used for offshore operations are mainly gr.5, and its modified gr.23 and gr.29 are also widely used. To adapt to medium corrosion and high temperature, the following improved alloys with added palladium and ruthenium can be used: gr.24, gr.29, gr.18, gr.28.
In short, there is a growing debate about the tradeoff between titanium's superior performance and its high cost. In the decision of a project materials, especially for offshore, offshore projects, designers face two choices: (1) choose low cost but not suitable for long-term use of materials;(2) choose expensive but long life materials. Cheap materials are more economical for one-time investment, but due to frequent maintenance and stop-work maintenance, later maintenance is difficult. Expensive materials cost more in the early stage but less in the later stage of operation and maintenance.
Titanium equipment because of its long service life and low operating costs can make up for its higher upfront investment, so it is completely reasonable to choose titanium metal over other structural metals.
