Persistent inhibition performance of amine polymers to inhibit clay swelling

Clay hydration and swelling can cause shale instability in the drilling of oil and gas wells. The persistent inhibition performance of polyether amine (PEA) and poly(vinyl alcohol- g -dimethyl aminopropyl methacrylamide) (PVA- g -DMAPMA) as amine clay inhibitors has been investigated through hot rolling dispersion test, bulk hardness test, and bentonite inhibition test. The micro-mechanism has also been explained by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and X-ray diffraction (XRD) analyses. Through the interaction of PEA and PVA- g -DMAPMA, the PEA can enter into clay platelets to exclude water molecules from entering and hydrating the clay, and the PVA- g -DMAPMA can affect the surface of clay minerals to prevent further intrusion of water molecules. Due to the effect of multiple cationic sites, both PEA and PVA- g -DMAPMA can maintain persistent clay inhibition and are less susceptible to reversing the adsorption.