Corrosion Causes and Control Measures of Gathering and Transportation Pipelines for Shale Gas

The problem of pipeline corrosion in Nanchuan shale gas field was gradually emerging. The causes of pipeline corrosion were analyzed from the aspects of pipeline transport medium and corrosion products. Through the optimization test and compatibility test in laboratory for bactericides and corrosion inhibitors, relevant corrosion protection measures were put forward. The results show that CO₂ existed in the shale gas, the produced water contained large number of SRB and Cl^-, and the corrosion products were mainly composed of Fe, O and C. The synergistic effect of CO₂, SRB and Cl^- was the main reason for the corrosion of pipelines. TK-S01 bactericide had the best bactericidal effect, whose sterilization rate reached 99.99% under the best injection concentration of 100 mg/L. KY-2 inhibitor had the best corrosion inhibition effect, whose inhibition efficiency reached 90% under the best injection concentration of 150 mg/L. The compatibility of TK-S01 bactericide and KY-2 inhibitor was good. There was no interaction on each other.