The Drill pipe body is typically made from low-carbon alloy steel. The manufacturing process begins with a round steel billet, which is produced through a continuous casting and rolling process. The billet is then heated in a large rotary furnace before being formed into a tubular shape by passing through an extruder and an automatic piercing mill. Subsequently, the tubular section undergoes further heating and is subjected to internal and external diameter sizing and straightening processes.
Upset Forging: The Critical Step
As the welded area is the weakest point during drilling operations, the seamless pipe requires thickening at both ends before welding to increase the thickness and enhance the strength of these vulnerable sections. This process ensures that the overall strength of the welded area exceeds that of the pipe body. Depending on the pipe diameter, there are three types of upset forging: internal and external thickening, internal thickening, and external thickening. The internal and external thickening method is the most commonly used.
The upset forging process begins with heating and uniform temperature distribution of the pipe ends. Next, the pipe ends are subjected to forging through hydraulic or pneumatic means. The external surface is shaped by a die, while the internal surface naturally forms due to the temperature gradient. Finally, the entire pipe body undergoes heat treatment, straightening, and non-destructive testing (NDT) inspection.
The critical aspect of upset forged pipes lies in the formation of the internal transition zone. This area is the weakest point and experiences the most complex stresses during drilling operations.
Approximately 70% of Drill pipe failures occur in this region, making it crucial for the overall quality and reliability of the Drill pipe.
Welding and Final Processing
After the upset forging process, the thickened pipe ends are welded together using friction welding, a solid-state welding technique that ensures a strong and reliable connection between the pipe body and the tool joints. The welded pipe sections then undergo machining to cut precise threads onto the tool joints, allowing individual Drill pipe sections to be connected securely.
Subsequent treatments, such as heat treatment, surface hardening, and protective coatings, are applied to enhance the Drill pipe's performance, durability, and resistance to wear and corrosion. Finally, each pipe is uniquely marked with identification numbers and other relevant information to ensure traceability throughout its service life.
By following these intricate manufacturing processes and stringent quality control measures, Drill pipe manufacturers like Vigor can produce reliable and high-performance pipes capable of withstanding the extreme conditions encountered during drilling operations, contributing to successful oil and gas exploration and extraction efforts.
Vigor will provide you with a reliable solution, Please contact us at info@vigorpetroleum.com.
