Pipeline corrosion, aside from pipes conveying chemically corrosive media such as acids and alkalis, primarily affects cooling water pipelines due to oxygen-induced corrosion caused by the use of untreated raw water internally. Corrosion damage also frequently occurs on the inner walls of compressed air pipelines with poor water flow.

Coiled tubing operates under harsh conditions and complex stress states. Failure modes can be categorized into deformation failure, fracture failure, and surface damage failure, with fatigue fracture failure accounting for a significant proportion. Fatigue life is a key indicator for measuring its reliability.

Based on research findings and experimental data from abroad, it has been discovered that, for coiled tubing with fixed materials and specifications, low-cycle fatigue life is most significantly influenced by internal pressure, followed by the effect of bending stress.

Xi'an LETRY specializes in manufacturing electro-hydraulic servo steel pipe bending fatigue test benches, primarily used for coiled tubing bending fatigue tests. These benches measure the fatigue cycles of hollow pipes under internal pressure and bending conditions, while also assessing the relationship between various parameters of the hollow pipes (such as outer diameter and expansion diameter) and obtaining the correlation between failure cycles and internal pressure, as well as failure cycles and outer diameter, expansion diameter, etc.

Working Conditions:

1. Meet the general working requirements of the testing machine;

2. The testing machine should be used in a clean, dust-free environment, complying with computer usage environment requirements;

3. The laboratory should have 50Hz AC power sources of 380V and 220V, with voltage fluctuations not exceeding 10% of the rated voltage; power: 32kW;

4. The installation ground in the laboratory should be level and capable of bearing at least three times the weight of the testing machine; testing machine weight: 3500kg;

5. Ambient temperature should be maintained between 0～30°C, with relative humidity not exceeding 85%;

6. Provide circulating cooling water source: pressure: 0.2～0.4MPa, flow rate: 90L/min;

7. Users should prepare 2 barrels of No. 32 aviation turbine hydraulic oil (Kunlun or Great Wall brand);

8. The laboratory should be free from vibrations, significant electromagnetic interference, and corrosive media;

9. The working area for the testing machine should, in addition to meeting normal operational needs, have at least approximately 1.2 meters of operating space around the main unit.

Coiled tubing technology is widely used in oil and gas field operations such as workover, drilling, completion, logging, and production enhancement, playing an increasingly important role in oil and gas exploration and development. Initially, coiled tubing gained a foothold in the market as an economical and effective wellbore cleaning tool. Subsequently, its application scope has continued to expand in oil and gas fields worldwide.