In OCTG,successive tubing is a new type of seamless casing material that has a single root length of several kilometers and can be repeatedly tortuous and complete multiple plastic deformations. Successive oil pipelines and their work and equipment are called “all-round working machines.” In foreign countries such as the United States and Canada, successive oil pipelines have become essential oil equipment for oilfield operations. The longest continuous fuel pipe is currently 9000m long. The core technology for this special pipe production is:
1, chemical elements
Because of the severe enforcement environment, there is a high demand for the mechanical and anticorrosive functions of the tubing connected to the tubing data. To optimize the chemical composition of the data, it is necessary to complete the entire process of cleansing manipulations such as exercise and rolling to minimize Detritus and S, P and other harmful elements content.
Because the work hardening caused by the proliferation of dislocations and the Bauschinger effect together, the rules for changing the strength of the pipe body are manipulated.
3, heat treatment
After the heat treatment of the pipe body, the best handling of the arrangement and function is accomplished, in particular high strength and high plasticity and low residual stress.
4, welding skills
For low-carbon microalloyed steels, HFW welding technology is currently mainly used to study the best welding skill parameters (such as current, voltage, frequency, welding speed, forming angle, extrusion amount, etc.), and to discuss weld and weld heat treatment skills. .
5, plate docking
In order to complete the production of HFW welded pipes, it is necessary to lengthen the plates first. Currently, TIG, MAG and plasma welding are the main methods used for the jointing of plates. The method being studied is to mix friction welding methods.
6, pipe joints
In the course of using the tubing, it may cause some damage. It is necessary to remove some of the damage or defects and connect the tubes by welding. The traditional docking method is usually selected using craft TIG welding, and the welding quality is difficult to control. At present, the automatic welding skill is used.
7, new production skills
For example, the CVR skill, that is, the successive tubes of the same specification used for the tube blanks, is heated to 940° C. via induction heating on the wire, and after thermomechanical rolling, the HFW weld seam is optimized or seamless on one hand, and the wall thickness is changed on the other hand. Reducing. In addition, there are special stainless steel joints and other laser welding skills.