Degradation profiles of poly(methylene oxide) and poly(glycolic acid) for inflow control devices in oil wells

摘要

The viability of the application of hydrolysable polymers, such as poly(methylene oxide) (PMO) and poly(glycolic acid) (PGA), in formation treatments in oil wells, was studied; we examined their addition to inflow control devices (ICDs), which are instruments used to control the oil-flow profile along production intervals. Thereby, the structural and morphological changes of PMO and PGA samples exposed to common chemicals, such as hydrochloric acid (HCl) and sodium chloride (NaCl) solutions and xylene, used in the procedure were evaluated under conditions similar to those observed in southeastern Brazilian offshore oil fields (temperature range=50-130 degrees C, 41.4 MPa). The aim of this study was to verify whether the polymers hydrolyzed and could be further removed from the ICDs. Techniques including high-pressure liquid chromatography, ion chromatography, C-13-NMR, differential scanning calorimetry, scanning electron microscopy, and optical microscopy were applied in this study. Xylene did not produce expressive effects in the samples. PMO was significantly affected by 15% HCl at 75 degrees C but was not completely dissolved after 24 h of exposure; this counter indicates its use. The PGA hydrolysis profile in NaCl brine was suitable for application around 75 degrees C. (C) 2016 Wiley Periodicals, Inc.