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. (C) 2016 Society of Plastics Engineers