As the blood of industry, oil plays an important role in the energy strategy. At present, the key to increasing oil production in China is to improve oil drilling technology. The expandable tube technology is an important new oil and gas engineering technology that was produced and developed at the end of the last century and at the beginning of this century. It is a mechanical or hydraulic method used underground to move the casing from top to bottom or bottom to top. The steel is permanently plastically deformed to achieve the purpose of the casing after expansion to close the casing wall. The use of expandable tube technology can greatly improve the production efficiency of drilling engineering in oil and gas development, save manpower, materials, time and cost, and drive the development of other related technologies. The US petroleum engineering authority Cook refers to the expansion tube technology as “oil drilling”. The moon landing project is one of the key technologies in the 21st century oil and gas industry, and the expansion pipe material is one of the most critical issues in the expansion pipe technology.
The duplex steel structure is mainly composed of ferrite and martensite, also known as martensite duplex steel. It has the characteristics of no yield extension, low yield strength, high tensile strength and good plasticity matching, and is expected to become the preferred material for the expansion of the oil industry. The excellent properties of duplex steels depend mainly on the morphology and quantity of martensite, while the quenching temperature has a decisive influence on the amount of martensite in duplex steels.
The chemical composition of suitable duplex steel for expansion tube was designed. The influence of quenching temperature on the microstructure and mechanical properties of duplex steel was studied. The results show that as the quenching temperature increases, the martensite volume fraction gradually increases, resulting in an increase in yield strength and tensile strength. When the quenching temperature is 820 ° C, the expansion tube can achieve the best overall performance with duplex steel.
Post time: Mar-15-2019
