Two hydrolyzable polymers, poly(methylene oxide) (PMO) and poly(glycolic acid) (PGA), were tested for association with mechanical systems to promote diversion of formation acid treatments in oil wells. Samples were confined to chemical products commonly employed in oil well completion processes, HCl 15% w/w and NaCl 23% w/w aqueous solutions, in separate metallic cylindrical cells, under conditions observed in southeastern Brazilian offshore fields (50 and 75°C and pressure of 41.4 MPa). Pristine samples were characterized by 13C‐NMR. Hydrolytic influences were evaluated by differential scanning calorimetry, scanning electron microscopy, wide angle X‐ray diffraction, and computerized microtomography. The intense effects observed showed a specific correspondence with each tested polymer and were evidenced by postexposure analysis. The results indicate that both polymers can be used in association with mechanical diverting systems to promote chemical treatment distribution and, therefore, improve oil well productivity. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47362.