Blast Cause of Tee Tube Connecting a Gas Recovery Well Branch and the Gas Collecting Main

After 3 years production running of a gas recovery well, a blast accident of the tee tube connecting the single well branch and gas collecting main happened. The causes were studied. The results showed that the blast accident was caused by pipe wall corrosion thinning resulting in overpressure of the pipe body. The corrosion of the pipe resulted from CO2 corrosion, high velocity erosion, local turbulent erosion and bimetallic effect. Local turbulent erosion and bimetallic effect were the main causes of the pipe wall corrosion thinning and bursting. In order to control the occurrence of bimetallic corrosion, the contact of two kinds of metal or alloy with different potentials should be avotd.