| Water-soluble acrylamide-based polymers are widely applied in the oil industry,such as displacement fluid,drilling fluid,and fracturing fluid because of their viscosity and rheological property.Currently,the most crucial acrylamide-based polymers is the partially hydrolyzed polyacrylamide(HPAM).However,under the condition of the reservoir temperature and salinity,HPAM structure was damaged,eventually led to the poor performance of the viscosity and rheological due to the hydrolysis and curl of molecule chains.In order to improve the structure stability of HPAM,two functional monomers have been introduced in HPAM chains to prepared two type of polymers.The hydrophobically associating polymer,denoted as PAAD,was prepared with acrylamide(AM),acrylic acid(AA)and N,N-diallyl-2-dodecylbenzenesulfonamide(DBDAP).The polymer,denoted as PAAT,was synthesized via copolymerization of acrylamide(AM),acrylic acid(AA)and N,N-diallyl-4-methylbenzenesulfonamide(TCDAP).The obtained copolymer was characterized by FTIR,1H NMR and intrinsic viscosity.And the hydrophobic associative behavior of PAAD was studied by a combination of the pyrene fluorescence probe and viscosimetry.The effect of synthesis conditions such as mass concentration of monomers and initiator,pH,and temperature on apparent viscosity of PAAD solutions was investigated.The water-soluble complexes containing hydrophobically associating polymer PAAD and a series of surface activity imidazolium-based ionic liquids(CnmimBr,n=6,8,10,12,14 and 16)were prepared.Incorporation of CnmimBr(n=1 0,12,14 and 16)in PAAD leaded to the white thick gel,while the pellucid solutions were obtained in complexes of PAAD and CnmimBr(n=6 and 8);addition of C6mimBr around critical micelle concentration resulted in a large decrease in viscosity of solution.Therefore,we particularly investigated the performance of PAAD/C8mimBr complex due to the favourable viscosity.The interfacial tension of PAAD/C8mimBr complex solution and crude oil could decrease to 0.85 mM/m under the high temperature and salinity conditions.Moreover,when temperature increasing from 30 to 90?,the viscosity of PAAD/C8mimBr complex decreased from 22.2 to 17.4 mPa·s exhibiting superior temperature resistance,and PAAD/C8mimBr complex also showed shear reversible performance for enhancing oil recovery(EOR)by rheological test.13C NMR study revealed that there existed interactions between PAAD and C8mimBr.The promising EOR of 21.65%can be obtained by PAAD/C8mimBr complex.The effect of mass concentration of monomers and initiator,pH,and temperature on anti-swelling ratio of PAAT solutions was investigated.The water-soluble complexes of PAAT and 3-methyl imidazoliumcation-based tetrafluoroborates ionic liquids for inhibiting shale hydration were prepared.And PAAT/HmimBF4 complex exhibited the highest anti-swelling ratio.The X-ray diffraction showed that compared with commonly used KCI,water-soluble complex of 0.3 wt%PAAT with 2 wt%ionic liquid HmimBF4 could remarkably reduce the d-spacing of sodium montmorillonite in water from 19.24 to 13.14 A and effectively inhibit clay swelling.It has also found that PAAT/HmimBF4 complex could retain 75%indentation hardness of shale,increase anti-swelling ratio up to 85%and decrease linear swelling ratio to 20%.13C NMR study revealed that there existed interactions between PAAT and HmimBF4.Moreover,the thermal stability of PAAT/HmimBF4 complex is superior to PAAT. |
PDF Full Text Request