In the past few decades, the severity of corrosion in the oil and gas industry has increased year by year. Because the offshore oil industry continues to push oil exploration deeper, it leads to higher pressure conditions and harsher environments. In addition, advanced technologies have increased the total capacity of domestic reservoirs, thereby increasing the life expectancy of subterranean wells and the concentration of corrosive agents in these wells. In order to adapt to these difficult environments and to safely prevent the high cost of component failure, it has become crucial to ensure that the right alloys are selected for use in the oil and gas industry. This creates an excellent application opportunity for duplex stainless steel 2205 and other duplex stainless steels.
At the end of the 1970s, when it was selected as a natural gas pipeline, duplex stainless steel was first introduced into the oil and gas industry. At the time, this option provided an important commercial breakthrough for Duplex 2205 (UNS S32305 / S31803). It not only helped the smooth application of duplex stainless steel 2205 to the oil and gas industry, but also incorporated many other industries. Until now, duplex stainless steel 2205, streamlined duplex, super duplex, and duplex have played an increasingly important role in both the onshore and offshore oil and gas industries.
Oil and gas production:
Oil and gas production processes vary according to the environment, but high-level steps remain relatively stable over time. Oil is found in reservoirs under the seabed or deep wells and extracted using small diameter high pressure pipelines with mixed gas and water. Once the oil mixture reaches the surface, it passes through the wellhead and is then typically fed through a larger diameter, lower pressure lateral conduit until it reaches the separator vessel. In the separator vessel, the gas rises to the top, the water flows to the bottom, and the oil separates out in the middle. The gas is usually re-injected into the reservoir, refined and sold or expanded. Water is injected into the reservoir. Then the oil is sent to the pipeline to the refinery.
The advantages of duplex 2205 and other duplex stainless steels:
Duplex stainless steel has two distinct advantages that make this material attractive to the oil and gas industry. First, it has excellent resistance to various corrosive media commonly found in both onshore and offshore environments. These mainly include CO2, H2S gases, chlorides, low pH conditions and water. The high resistance to chloride-induced stress corrosion cracking of dual-phase steels is particularly important. Second, its high intensity is very beneficial in dealing with the high levels of high pressure encountered.
Duplex stainless steel can also provide some material cost advantages compared to alternatives, but up-front costs are usually not a major driver, especially for seabed extracts. The huge cost of failure in the oil field makes the best material for the job to be selected in the early stages. Therefore, it is important that all cost calculations include life-long maintenance and potential cost risks due to failures so that the costs can be really assessed when selecting materials.
Duplex stainless steel application:
Duplex stainless steel 2205 and other biphasic grades are increasingly preferred materials for process piping systems, separators, scrubbers, pumps, manifolds, X-mas tree assemblies, flow lines, and piping for transport of corrosive oils and gases. . In the case of resistance to design stress, super and super biphasic grades are preferred. The biphasic grade has become the standard configuration for flexible tubes and umbilicals. Not only does duplex stainless steel prevent corrosion, but they have the ability to support their weight in deep water.
Source: China Duplex Stainless Steel Pipes Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)