Numerical Simulation of Corrosive Flow in the Production End of Carbon Capture, Utilization, and Storage-Enhanced Oil Recovery Backflow Wastewater Pipeline

In a carbon capture, utilization, and storage-enhanced oil recovery (CCUS-EOR) system process, the high carbon dioxide content and high acid value of the fluid at the extraction end are treated at the wastewater treatment station and then flow through the transfer station of the gathering system. The reinjection system’s pipelines at the transfer station are prone to corrosion and leakage risks. A steady-state nonisothermal flow and corrosion model was established to examine this corrosive phenomenon by utilizing the principles of fluid dynamics and electrochemical corrosion. The study examined how flow velocity, temperature, pressure, and pH affected the pipeline’s corrosion. Simulation results showed flow velocity increased in specific places of both straight and curved pipeline sections. The velocity near the inner wall of curved portions was higher, making them more susceptible to cavitation damage. Faster flow rates, lower pH values, higher temperatures, and smaller pipeline diameters all contributed to increased corrosion on the inner walls of wastewater pipelines. The highest simulated corrosion rate was 8.3162 mm/a corresponding to the smallest pipeline diameter (100 mm), lowest pH (4), highest temperature (60°C), and highest flow rate (36.847 m/s). When designing the CCUS-EOR system, the nonmetallic pipeline should be given priority. If carbon steel metal pipelines are utilized, it is best to use larger-diameter materials in the engineering design. Additionally, procedures such as adding corrosion inhibitors to regulate pH values and lowering the temperature of wastewater conveyance might be explored to reduce corrosion on the pipeline’s inner walls.