- Classification by Material
- Carbon Steel Oil Pipes: They have high strength and good toughness, and the price is relatively low. They are one of the most widely used oil pipe materials and are suitable for most conventional oil and gas extraction environments.
- Alloy Steel Oil Pipes: By adding alloy elements such as chromium, molybdenum, and nickel to carbon steel, they have higher strength, corrosion resistance, and high-temperature resistance. They are often used in some special environments with high requirements for oil pipe performance, such as high-temperature and high-pressure oil wells and oil wells with corrosive media.
- Stainless Steel Oil Pipes: They have excellent corrosion resistance and oxidation resistance and can maintain good performance in harsh corrosive environments. They are commonly used in corrosive environments such as offshore oil and gas extraction and high-sulfur oil and gas fields.
- Titanium Alloy Oil Pipes: They have high strength, low density, good corrosion resistance, and anti-fatigue performance. They are especially suitable for extreme and harsh oil and gas extraction environments such as deep sea, high temperature and pressure, and strong corrosion. However, due to the high cost, their application is relatively limited.
- Classification by Manufacturing Process
- Seamless Oil Pipes: They are manufactured by processes such as piercing, hot rolling, and cold drawing. They have the advantages of no weld seam, high strength, and good sealing performance. They can withstand high pressure and stress and are the main type of petroleum oil pipes, widely used in various oil and gas wells.
- Welded Oil Pipes: They are made by rolling and welding steel plates or steel strips. The manufacturing process is relatively simple and the cost is low. However, the strength and sealing performance at the weld seam may be inferior to those of seamless oil pipes. They are generally used in occasions where the performance requirements for oil pipes are not particularly high and the pressure is low.
- Classification by Usage Function
- Oil Production Pipes: They are mainly used to transport crude oil from the bottom of the oil well to the ground. Their performance requirements mainly focus on wear resistance, corrosion resistance, and good fluid transportation capacity.
- Water Injection Pipes: They are used to inject water into the oil well to increase the pressure of the oil layer and promote the extraction of crude oil. The water injection pipes need to have good corrosion resistance and anti-scaling performance to prevent the impurities and chemical substances in the water from corroding and blocking the oil pipes.
- Gas Production Pipes: They are used to transport natural gas. In addition to requiring a certain strength and sealing performance, their corrosion resistance to acidic gases (such as hydrogen sulfide, carbon dioxide, etc.) that may be contained in natural gas also needs to be considered.
- Composite Oil Pipes: They are made of two or more different materials through a composite process, such as composite oil pipes with plastic or rubber linings. They not only have the strength of metal oil pipes but also have the advantages of the lining material such as corrosion resistance and low friction coefficient, and can be designed and manufactured according to different usage requirements.
- Classification by Connection Method
- Threaded Connection Oil Pipes: Threads are processed at both ends of the oil pipe and connected by threads, which is the most common connection method. This connection method is convenient for installation and disassembly, but attention needs to be paid to the processing accuracy and sealing performance of the threads to ensure the reliability and sealing performance of the connection.
- Welded Connection Oil Pipes: The ends of the oil pipes are connected by welding. The welded connection has high strength and good sealing performance, but it is relatively difficult to install and disassemble and is generally used in some permanent installation occasions.
- Special Connection Oil Pipes: For some special usage requirements and environments, various special connection methods have been developed, such as clamp connections and flange connections. These connection methods usually have the characteristics of quick installation, convenient disassembly, and good sealing performance and are suitable for occasions where the oil pipes need to be frequently replaced or repaired.