Evaluation And Cause Analysis Of The Use Of Mechanical Composite Pipes In Oilfields

With the rapid development of China’s economy,people’s demand for energy is also increasing day by day.In recent years,although China has vigorously developed cleaner and more environmentally friendly new energy,oil and gas are still the most important energy sources in China,as well as the most important energy and strategic materials.Nowadays,China has become the world’s oil and gas exploitation power,the completion of the "West-to-East Gas Transmission" project also marks that China has become a major country in the construction of oil and gas transportation projects,and oil and gas storage and transportation technology ranks among the best in the world.In recent years,China has vigorously developed oil and gas resources and developed and built many oil fields.Among them,Tarim Oilfield is one of the large oilfields focused on construction in Xinjiang.After years of exploitation,Tarim Oilfield has become increasingly severe in its production environment.Long-distance oil and gas transmission and high C02,H2 S mining environment require high performance of pipes,and double alloy composite pipes can not only meet the requirements of oilfield operations but also ensure safe oil and gas production.This paper studies the composition of yingya condensate line jam,and through the evaluation of three composite pipes of 316 L,2205 and low alloy steel,fatigue and corrosion simulation test,the main influencing factors of the fatigue performance of continuous pipes and the corrosion conditions and stress corrosion cracking conditions in different environments are mastered.After analysis,in the jamming accident of the Yingya condensate pipeline,the main component of the pipeline jam is the wax precipitated from the tube wall at low temperatures,and only light hydrocarbons in the 5 dissolving agents have a good solubility ability to the jam.Duplex stainless steel(2205),austenitic stainless steel(316L)and low alloy steel can meet the requirements of drilling fluid environment operation,of which low alloy steel continuous pipe is more suitable for such drilling fluid environment operations due to its low cost.The three kinds of composite pipes have shown good corrosion resistance in the oilfield high C02,H2 S oil and gas exploitation environment,and the high-strength austenitic stainless steel has the best corrosion resistance in the production environment,but its cracking sensitivity is high,and duplex stainless steel continuous pipes should be selected for operation in the high H2S/CO2 production environment.Duplex stainless steel and low alloy steel have a high corrosion rate in tarim acid systems,and duplex stainless steel has selective corrosion in four types of fresh acid environments.