Study on Cavitation Behavior of Pipe String in Gas Storage Well under Gas-Liquid Environment

Abstract

In the long-term and continuous operation process of UGS injection-production well, the outer casing joint of the oil string is prone to failure. This causes gas to enter into the annular space between the casing and string forming the gas-liquid two-phase, leading to the issue of cavitation of the string. Therefore, herein, the string cavitation caused by the gas leakage in UGS gas well during the injection and production process is analyzed through electrochemical measurements and image characterization. The results show that the pipe string had no corrosion characteristics during the long time of injection and production owing to the action of corrosion inhibitor and passivation film of 13 Cr. During the 24 h experiment, when the leakage pressure reached 5 MPa, the pipe string was mainly layered corrosion. When the pressure increased to 10 MPa, the formation and rupture of gas bubbles on the metal surface led to the destruction of two protective films, and clear cavitation pits appeared on the metal surface. Greater the pressure, more prominent was the cavitation effect.

Effect of Ce on Inclusions and Precipitates in 10Cr5MoV Steel and the Microscopic Behavior of Solid Solution Ce in Steel

“…Chromium‐ and nickel‐based corrosion‐resistant materials are expensive and sensitive to stress corrosion, while medium‐ and low‐alloy steels containing Cr show promising advantages. [ 4,5 ] As a result, many researchers have focused on refining the steel microstructure and improving inclusions in the steel to enhance the steel's performance in oil well pipes. For example, the addition of elements such as Cr, Mo, and Ni can improve the steel microstructure and increase the stability of passivation films, thus enhancing the corrosion resistance of the steel.…”