What are the inspection standards for oil drill pipe?

Oil drilling tools generally refer to special tools used in the oil production process. The main component is seamless steel pipe, which has strong physical properties and has the advantages of fatigue resistance, wear resistance and bearing alternating loads. In addition, the oil drilling tools also include hexagonal drill pipes, drill bits, shock absorbers, drill collars , stabilizers and other components. The oil drill pipe is an important component located in the oil drilling equipment, which undertakes tasks such as penetrating the formation, transmitting power and supplying the drill bit. In order to ensure the reliability, safety and efficiency of the drill pipe, a series of inspection standards need to be strictly implemented during production and use. This article will elaborate on the inspection standards of oil drill pipes in detail, hoping to be helpful to readers.

Oil drilling tools include drill pipes, hexagonal drill pipes, drill bits, shock absorbers, stabilizers and other key components. These tools are subjected to great pressure and wear during work, and the threaded part is particularly prone to breakage or failure, which leads to accidents. Therefore, it is particularly important to conduct regular inspections of drill pipes. Through electromagnetic detection, magnetic particle detection, ultrasonic detection and other technologies, cracks and defects on the drill pipe can be discovered in time, thereby avoiding the occurrence of dangerous accidents and improving the safety and efficiency of drilling operations.

Oil drill pipes bear huge loads during drilling, so their strength and toughness are important guarantees for ensuring the safe operation of equipment. The physical performance detection of oil drill pipes mainly includes the following aspects:

Static tensile test: This test mainly determines the yield point, ultimate tensile strength, elongation at break and cross-sectional shrinkage of the drill pipe. These indicators can effectively evaluate the force bearing capacity and deformation performance of the drill pipe at work.

Impact toughness test: This test is used to detect the resistance of the drill pipe to cracking when subjected to extreme impact loads, especially the brittleness resistance under low temperature conditions. Through this test, the safety of the drill pipe under harsh working conditions can be evaluated.

Hardness test: Hardness test is an important means to evaluate the wear resistance and corrosion resistance of the drill pipe surface. The hardness of the drill pipe surface reflects its surface state and durability, and can also reveal the internal structure of the material.

The dimensional accuracy of the oil drill pipe has a direct impact on its fit with other components and the sealing performance of the joint. Therefore, the dimensional accuracy of the drill pipe must be strictly controlled during production and use. The main detection contents include:

Outer diameter deviation: The outer diameter deviation detection is to evaluate the roundness and eccentricity of the drill pipe and ensure the balance between the drill pipe section and the central axis.

Length deviation: By measuring the actual length of the drill pipe and comparing it with the design size, it is determined whether the drill pipe length meets the standard requirements to ensure its stability during connection and use.

Joint geometry: The geometric indicators such as roundness, flatness and conicity of the joint directly affect the tightness and sealing performance of the joint connection. Accurate geometry can effectively prevent leakage or breakage during drilling.

The drill pipe thread part is an important area where the drill pipe is connected to other tools. The quality of the thread is directly related to the service life and work safety of the drill pipe. There are several commonly used thread detection methods:

Ultraviolet lamp method: Use ultraviolet lamp to detect cracks and defects on the thread. The UV lamp should have a suitable wavelength (320-400nm) and sufficient UV irradiance (>1000uw/cm²) to ensure the accuracy of the detection.

Magnetization method: By magnetizing the drill pipe and spraying magnetic suspension, tiny cracks on the thread or pipe body can be detected. This method requires high skills of the operator, but it can effectively detect deep-seated defects.

Ultrasonic testing: Ultrasonic testing is a commonly used non-destructive testing method with high sensitivity and strong penetration. By detecting the propagation of ultrasonic waves in the drill pipe, internal defects can be found and their severity can be assessed.

Penetrant testing: Use penetrants to penetrate into tiny cracks in the threads and show the defect location through capillary action. This method is simple to operate and low in cost, and is suitable for the detection of a variety of drilling tools.

The metallographic and microstructure testing of drill pipes is an important means to judge its internal organizational state, performance and process quality. The relevant testing standards include:

Testing of organizational density and balance. For oil drill pipes, the main organizational units are ferrite, bainite, martensite, etc. The determination of organizational density and balance can reflect the heat treatment effect of steel.

Determination of grain level and grain size. Grains are an important component of the material. The determination of grain level and grain size can measure the super compliance and plasticity of the drill pipe.

Detection of surface defects. During the drilling process, surface defects such as pits and cracks may appear on the surface of the oil drill pipe, which will have a negative impact on oil production and equipment stability. Therefore, it is necessary to make corresponding judgments on surface defects.

Composition is one of the important factors affecting material properties and organization. The chemical composition detection of oil drill pipes involves several aspects such as ferrite, chromium, and molybdenum content of steel:

Analysis of ferrite composition of steel. The content of ferrite in the drill pipe directly affects its tensile properties and the selection of working temperature.

Analysis of metal composition of drill pipe. The detection of chromium, molybdenum and other elements in oil drill pipes can reflect the corrosion resistance and wear resistance of drill pipes.

As a key tool in drilling engineering, the quality of oil drill pipe is directly related to the efficiency and safety of drilling operations. Through strict physical performance, dimensional accuracy, thread, metallographic structure and chemical composition testing of drill pipe, its working performance in complex environments can be effectively guaranteed. Strict implementation of these testing standards is the key to ensure the efficient and safe operation of oil drill pipe, which is of great significance to reducing drilling costs and improving economic benefits.