Analysis of Corrosion Causes and Preventive Measures for Water Injection Well Tubing in Gasi Oilfield

The Gasi Oilfield, a major production block of the Qinghai Oilfield, has faced significant challenges in water injection development in recent years. Severe tubing string corrosion in injection wells has increased the difficulty of downhole operations, hindered the construction of water injection networks, and severely hindered the development of the oilfield. Through corrosion investigations and mechanism studies, it was identified that the corrosion issues in the tubing strings of Gasi’s injection wells primarily result from localized electrochemical corrosion under CO2 scale, sulfate-reducing bacteria (SRB) corrosion, chloride ion (Cl-) corrosion, and high salinity conditions. Experimental analysis of corrosion mechanisms revealed a critical pattern: the corrosion rate exhibits a sharp upward trend with increasing temperature, pressure, and flow velocity. Based on the root causes of corrosion, this paper proposes effective preventive measures and recommendations for tubing corrosion in water injection wells, providing practical guidance for maintaining the integrity of Gasi’s injection well systems.