Synthesis and property evaluation of a novel polyacrylamide‐montmorillonite composite for water shutoff and profile control in high salinity reservoirs

Polyacrylamide‐montmorillonite organic‐inorganic composites (poly[AM/O‐MMT]) were synthesized by copolymerization of acrylamide (AM) on organic modified montmorillonite (O‐MMT) using N,N‐methylene‐bis‐acrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator in an aqueous solution. The montmorillonite (MMT) was modified by methacryloyloxy ethyl dimethyl hexadecyl ammonium bromide (DMB) which was synthesized by 2‐(dimethylamino) ethyl methacrylate with 1‐bromohexadecane. The FTIR and XRD were used to verify the organification of MMT with DMB. The effects of the amount of the DMB and O‐MMT on water absorption were studied. The swelling behavior in different saline solution and re‐swelling ability in distilled water were investigated. The results showed that DMB and O‐MMT content have an important effect on the water absorption of the composites. The addition of the DMB enhanced the salt resistance and delayed the swelling speed of the poly(AM/O‐MMT). Simultaneously, the toughness was measured. The water blocking and profile control ability were evaluated by core physical simulation experiments. The results indicated that the poly(AM/O‐MMT) has good plugging ability and profile control ability. The properties tested indicated that the poly(AM/O‐MMT) has a promising prospect to be applied as a profile control or water shut‐off agent for enhanced oil recovery in high salinity reservoirs. POLYM. COMPOS., 39:368–376, 2018. © 2016 Society of Plastics Engineers