Seamless steel pipes are widely used in our daily lives, and one of the most important application areas is to transmit energy as our energy channel, including oil, natural gas, etc. It can be laid not only on land but also on the seabed, which brings great convenience to the energy circulation in different regions. It is a transportation method that cannot be matched by land and sea transportation.
In today’s society, protecting the safety of energy channels is becoming more and more important. The damage to the Nord Stream pipeline has had a great impact on people, not only increasing people’s living costs, but also seriously affecting regional security. As such an important means of production, what is so special about the oil transportation pipeline? Let’s take a look at the knowledge of seamless steel pipes and oil casings. Seamless steel pipe oil casing is the lifeline to maintain the operation of oil wells. It is mainly used to support the well wall of oil and gas wells to ensure the normal operation of the entire oil well during the drilling process and after completion.
Oil pipes and oil casing are different from ordinary seamless steel pipes. Due to the complex geological environment and different geological conditions, the underground stress state is complex, and the combined effects of tension, compression, bending, and torsional stress on the pipe body put forward higher requirements for the quality of the oil casing itself.
In the API SPEC 5CT standard for oil pipelines, the steel grade of oil casing and oil pipe indicates its yield strength and some special characteristics. The steel grade is usually indicated by 1 letter and 2 or 3 numbers, such as N80.
In most cases, according to the order of letters in the alphabet, the later the letters, the greater the yield strength of the pipe. For example, the yield strength of N80 grade steel is greater than that of J55. The digital symbol is determined by the minimum yield strength of the pipe expressed in thousands of pounds per square inch. For example: the minimum yield strength of N80 grade steel is 80,000lb/in2. The oil casing steel grades listed in API SPEC 5CT standard are: H40, J55, K55, N80, M65, L80, C90, C95, T59, P110, Q125; oil casing steel grades are: H40, J55, N80, L80, C90, T59, P110.
Oil casing Each well needs several layers of oil casing according to different drilling depths and geological conditions. After the oil casing is lowered into the well, cement is used for cementing. Unlike oil pipes and drill pipes, it cannot be reused and is a one-time consumable material. Once the oil casing itself is damaged for some reason, it may lead to a reduction in production of the entire well or even scrapping. Therefore, the consumption of oil casing accounts for more than 70% of all oil well pipes.
Post time: Jul-04-2025