Swelling properties and mechanism of soluble Al-Ga-In-Cu-Mg aluminum alloy prepared by powder metallurgy

Purpose This study aims to develop powder metallurgy (PM) Al-Ga-In-Cu-Mg aluminum alloy with huge expansion rate in high-temperature and high-pressure environment for the downhole packers in oil and gas wells. Design/methodology/approach This study investigates the microstructure, swelling performance and swelling-sealing mechanism of Al-Ga-In-Cu-Mg aluminum alloy prepared with gas atomization powder using a scanning electron microscope equipped with an energy-dispersive spectroscopy, X-ray diffractometer and simulation experiment for underground hydration reaction in high-temperature and high-pressure environment with customized molds. Findings The PM Al-Ga-In-Cu-Mg alloy exhibits excellent expansion rate of 150% in 5 Wt.% KCl solution at room temperature, forming dense layered products with a sealing pressure resistance exceeding 70 MPa under simulated downhole conditions (200°C and 15 MPa). Corrosion products in hydration reaction are mainly consisted of Al(OH)3 at room temperature and AlOOH under high temperature and high pressure, respectively. The densification of the products is primarily achieved under various pressure. Originality/value This study provides data support for understanding the corrosion and swelling-sealing mechanism of PM Al-Ga-In-Cu-Mg aluminum alloy in the simulated underground environment, and theoretical guidance for next-generation oil and gas well packer materials.