A Research Of Ground Engeering Materials And Key Construction Technology In High Acid Gas Field

At present in the world, one after another natural gas field, it high contains H2S,have been discovered, regarding the high acidic natural gas environment, carbon steel material is still the first choice metal material. In the high acidic natural gas field, there is some technical requirement when the carbon steel material used. The technical requirement is additional requirement. The carbon steel material not only meet needs of correlative standardm, but also must meets the needs of the additional requirement. This dessertation has researched on corrosion mechanism, assessment method, assessment experiment, and weld technology, to the carbon steel materia in high acidic environment. This provides the safeguard for the high acidic natural gas field ground project safe design. This also lays a foundation for establishment corresponding norm and the standard for steel material choice and welding technology in the high acidic natural gas field. In chapter two, metal material main corrosion behavior and influence factor described. In chapter three, existing standard and testing method analysised, considering the fact of the Luo Jia Zhai high acidic natural gas field, testing method and acceptance check target established for sulfide stress cracking (SSC) in the high acidic environment. Regarding high acidic natural gas field environment choice metal material, if cannot provide a proof documents which the material used more than two years in a similar acidic environment, a environment condition simulated should be used to carry on the SSC appraisal experiment. Test result qualified is that, along the thickness direction, there is no SSC crack. When establisheing hydrogen crack (HIC) test method and approval target in the high acidic environmental condition. After the HIC experiment completed, carrieing on the following target determination according to each test specimen single section maximum value:the crack longth ratio (CLR)<10%, the crack thickness ratio (CTR)≤3%, and the crack sensitive ratio (CSR)≤1%.This dessertation, in chapter four, chapter five and chapter six, has finished evaluation test research for forge piecethe metal material and pipeline steel, and has finished anti-sulfur performance research for steel pipeline welded, and, for the first time, put forward "High acidic natural gas environment forge metal material specification" and "High acidic environment L245 and L360 steel pipe specification" and "High acidic natural gas environment carbon steel pipeline construction weld anti-sulfur performance specification".Through research the material choice of ground engineering facilities and construction technology in high acidic natural gas field, this dessertation provides a technical support for choice of metal material in the design of ground engineering, and a technical support for welding technology, the achievement in scientific research by this dessertation has consummated the corollary technology for the choice of ground engineerig material, and for the corrosion prevention, in high acidic natural gas field in domestic and has enabled a essential security in developing the "three high" natural gas field. And has laid the foundation of reviseing related material standard and technology specification for safe design in the future.