The Priority Choise Study Of Shaft Pipe Material For High-sulfur Gas Field

Since there is produced gas contained hydrogen sulphide, carbon dioxide, sulfur deposit and oxygen during the development of high sulfur gas field, corrosion cracking could occur in drill stem, wellbore and wellhead equipment. Sulfide stress corrosion and electrochemical erosion by hydrogen sulphide carbon dioxide is the major part, moreover, bimetallic corrosion could occur between unlike material of wellbore and down hole equipment. The thesis evaluated the inoxidizability of unlike material by three parts.Firstly, the inoxidizability evaluation of antisulfur steel has been performed. Two kinds of antisulfur steels are tested by static state coupon zero-gravity test, HPHT evaluation test, sulfur deposit corrosion evaluation test and sulfide stress cracking evaluation test. The corrosion mechanism, regular pattern and corrosion products are also studied.Secondly, the inoxidizability evaluation of high hastelloy steel has been obtained yet. The inoxidizability evaluation of high hastelloy steel is studied by HPHT corrosion test of acid fracturing acidizing fluid system, sulfide stress cracking comparative test and analog environment test, sample crack appearance and surface product analysis are also included.Finally, bimetallic corrosion evaluation has been presented. Make researches on antisulfur steel+alloy bimetallic corrosion, bimetallic corrosion between hastelloys, and the comarison of uniform corrosion rate between hastelloy and carbon steel. Temperature, pressure and sulfur that effected bimetallic corrosion are also studied.