| Chemical flooding is the essential method in the middle and later period of oil reservoir,and the polymer/surfactant compound flooding,which is widely used in chemical flooding,has successful precedent.The compound flooding can both increase the sweep efficiency and displacement efficiency,but its chromatographic separation effect limits the recovery efficiency of oil.As a kind of polymer flooding,polymeric surfactant has great development potential without chromatographic separation phenomenon in oil field.In previous research,the research group synthesized a new surfmer which was synthesized a new polymeric surfactant.However,because of the steric-hinerance effect and reactivity,the surfiner cause disadverse effect to polymer.Therefore,in this paper,the polymer molecular structure was designed for ensuring the sueface activity and increasing reactivity of surfmer to synthesize a new polymeric surfactant,and researched the solution properties and the feasibility of oil displacement.The work of this thesis included the following:1.Design of polymer molecular structure:In order to improve the surface activity and increasing reactivity of surfiner,long chain alkyl and quaternary ammonium groups,which also could increase dynamic retention to improve mobility control ability,were introduced,and double bond position was changed which was connected to methyl group,and sulfonic group was introduced to improve salt tolerance.2.Synthesis and characterization of surfiner:Synthesize the surfmer through MMA,DMAE and bromododecane.And apply the FT-IR and 1HNMR for the determination of characterization,and interfacial tension reached minimum 4.3 mN/m at 1500 mg/L.3.Synthesis and characterization of polymeric surfactant:The optimal synthesis conditions were determined by orthogonal and single-factor experiment:total monomer concentration was 25%,amount of initiator is 0.55%,AMPS concentration was 4.5%,surfmer concentration was 6%,and the temperature was 42?;and the final polymeric surfactant,which named HPASD,had cationic degree 3.19%and the reaction rate of surfmer was 53.18%.FT-IR and 1HNMR confirmed the structure of polymer.The dynamic/static state laser scattering instrument showed Mw=1.62×106 g/mol,Rg=60.8 nm,A2=6.43×104 cm3·mol/g2 and Rh=188.1 nm at 2000 mg/L.The ESEM showed the HPASD had tight mesh structures and some spheroidal structures were discovered between the mesh skeleton.4.Polymeric surfactant solution properties:The viscosity of HPASD reached 300 mPa·s at 3000 mg·L-1,and the results of HARK MARS showed the viscosity and the elasticity at 0.01-6 Hz and over 6 Hz,respectively.With decreasing interfacial tension ability and emulsifying ability,the interfacial tension of the minimum value was 9.8 mN/m,the lowest rate of water was 8.3%.The viscosity of HPASD was 113.1 mPa·s at 90? at 2000 mg/L.Under 22908 mg/L salinity,viscosity of HPASD decreased to 15.8 mPa·s at 2000 mg/L.5.Displacement experiments:HPASD had great injectivity at 2000 mg/L with simulated water when permeability over 90×10-3 ?m2.of larger Rh and quaternary ammonium groups,the dynamic retention of the copolymer was higher,and the retention increased with decreasing of permeability of porous medium,which made the RF and RRF increased with that.These means HP ASD had better mobility control ability. |
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