1. Structure: There is deposition of tungsten alloy layer on inner and outer walls of API standard pipes. Liner pipes are perforated on the casing backing material (called liner pipes after drilling), and there are deposition of tungsten alloy layer on inner and outer walls of pipes.
2. Performance Indicators:
Mechanical Property: The pipe meets API standards.
Anti-corrosion Property: Resistance to H2S/CO2 corrosion in high temperature, salt water corrosion, alkali corrosion and weak acid corrosion, meeting the corrosion resistance requirements of NACE 0177 standards.
Wear Resistance: Good, equivalent to that of hard chromium layer.
Hardness of Tungsten Alloy Layer: ≥650HV
Tungsten Alloy Layer and Backing Material Binding Force: According to GB/T5270-2005 testing, the plating layer does not crack or peel off.
Threaded Connection: The threads are of good resistance to thread gluing.
Appearance: Uniformly bright, showing silvery white
Thickness of Tungsten Alloy Layer: ≥60μm
3. Performance Testing Wear and Corrosion Resistance Test: Passed a variety of the wear and corrosion resistance tests carried out by Xian CNPC Tubular Goods Research Institute, Xian Maurer Petroleum Engineering Laboratory, and Quality Supervision and Inspection Center of Surface Covering Layer Products for Machinery Industry.
Gas Seal Test: Passed the gas seal tests of Xian CNPC Tubular Goods Research Institute.
Corrosion Detection Test in Yuanba Gas Field (Xian Maurer Petroleum Engineering Laboratory)
| Test Item | Test Standards | Testing Organization |
| Corrosion Rate Corrosion Morphology | NACE RP-0775-2005 | Xian Maurer Petroleum Engineering Laboratory |
| Conclusion | In simulated Yuanba corrosive environmental conditions (partial pressure of H2S: 5MPa, partial pressure of CO2: 11MPa, elemental sulfur content: 10g/L, chloride ion content: 80000mg/L, temperature: 160℃), the uniform corrosion rates of 1# and 2# samples are
0.0119mm/a and 0.0076mm/a respectively,
the uniform corrosion is mild, and no obvious local corrosion appears on the surface of the samples.
In simulated corrosive environmental conditions of residual acid flowback (partial pressure of H2S: 5MPa,
partial pressure of CO2: 11MPa; corrosive medium:
residual acid prepared by Southwest Oil and Gas Field Engineering Institute, with PH value adjusted to 4.0;
temperature: 160℃), the uniform corrosion rates of
the samples are 0.0069mm/a, the uniform corrosion is mild, and no obvious local corrosion appears
on the surface of the samples. |
