Simulation and Analyze of A Failed Coiled Tubing Job in A Sour Gas Well With Effect of O2 on Corrosion Behavior

Despite purity problems of membrane nitrogen generator units, the application of these technologies is extensively increasing for coiled tubing# in cases, where prolonged and continues unloading of heavy weight fluids within the well is needed, the use of these units are reasonable# since the initiation of corrosion reactions chain is presence of o2 , then high amount of o2 causes severe weight reduction while h+ and cl- ions from formation water and sour gas intensively increase corrosion reaction# such reactions dramatically decrease the sweet life of coiled tubing and highly increase the risk of fatigue and remaining in well# hydrodynamic corrosion analysis in a transient multi phase flow simulator can predict corrosion during an unloading operation in presence of o2 impurities in oilfields with h2s gas in this survey# with help of weight reduction test for a field samples of corroded coiled tubing and simulation scenario, results of failed operation in a sour volatile oil well with 8000 ppm h2s content is modeled# technical methods suggested for decreasing coiled tubing corrosion for safer operation criteria based on simulation with different o2 impurities contents in well condition# finally weight loss, flow regime, and impurity content are discussed together# rate of corrosion in milli gram per year with investigating hydrodynamic corrosion and flow regime implemented valuable point of view for a real case prediction# by controlling weight loss and impurities, safer operation can be conducted with reducing risk concepts#