Tubing pipes (or tubing for short) are widely used in the gas and oil industry: for the construction of oil and gas wells, hoisting and repair work, transportation of various liquids and gaseous substances. Such products work in severe and harsh operating conditions: this is constant pressure, and high mechanical loads, and the impact on the walls of aggressive environments. In addition, tubing pipes are constantly exposed to corrosion and erosion.
All this requires high strength from the products, they must ensure the tightness and reliability of the entire system. For fastening pipes, a threaded connection is intended . It provides high tightness, strength under conditions of increased loads, wear resistance and maintainability of products, as well as good patency of the columns in wells with a complex profile.
The tubing turns off the following types of pipes :
- smooth;
- smooth in accordance with GOST 633-80;
- smooth high-tight;
- smooth high-tight in accordance with GOST 633-80;
- smooth with a seal assembly;
- smooth high-tight;
- pipe tubing with upset ends ARI 5CT;
- with increased ductility;
- with increased cold resistance.
Requirements for tubing pipes
Tubing pipes and couplings used to connect them are subject to stringent quality requirements, which ensure reliability and durability of products. So, on the inner and outer wall there should not be cracks, delamination, shells. It is possible to strip or cut out these defects, but the following condition must be met: the embedment depth must not exceed the maximum minus cut-off in the wall thickness.
The number and size of defects on tubing pipes and couplings to them are strictly regulated. Exceeding permissible standards is excluded.
If the tubing pipe is lowered into the well, it is necessary to check its inner diameter and overall bend using a mandrel, the length of which is 1250 mm, and the diameter depends on the diameter of the item being tested. Especially this procedure must be carried out in the case of using rod pumps or in the presence of deposits of salts, gypsum, paraffin.
Each tubing pipe must be marked. The marking is applied at a distance of about 0.4-0.6 meters from the end of the product by rolling or by impact and must contain the following information: nominal diameter of the pipe, its number, strength group, wall thickness, name of the manufacturer and production date. All sizes should be indicated in millimeters. The marking is highlighted with light paint, resistant to various influences.
The tubing pipe is produced according to technical documents, which may differ for each individual manufacturer, however, the general requirements should not contradict the accepted conditions. The main differences are in different threads of the trapezoidal profile, sealing elements, etc.
In general, the tubing pipe must be of high quality and durable, only then will it ensure the reliability of all systems in which it is used.