Study On Synthesis And Properties Of Sulfonated Modified Polyacrylamide For EOR

Ternary sulfonated modified polyacrylamide(SPAM) successfully prepared by redox system, azo system and compound initiator system with acrylamide(AM)/2-acrylamide-2-methyl propane sulfonic acid(AMPS)/dimethyl amino ethyl methacrylate(DMAEMA). Determine the optimal preparation conditions under two-stage polymerization with composite initiator, monomer concentration of 33 wt%, the mass ratio of monomer AM: AMPS=19:1, the third monomer is 0.2 wt%, carbamide is 0.02 wt%, EDTA is0.01 wt%, TEMED is 10 μL, p H 8, AIBA is 0.002 wt%, ratio of oxidant and deoxidizer is 7:0,ammonium persulfate is 0.003 wt%.The SPAM were characterized by Fourier transform infrared(FT-IR), Nuclear magnetic resonance(NMR), Thermogravimetric analysis(TG-DTG), Solid contents determination and the test of relative molecular weight. The ternary sulfonated modified polyacrylamide which had the molecular weight of 9.5 million and solid content of 88% by copolymerization. The viscosity retention rate of SPAM reached 56.7% from 30 °C to 99 °C at the solution of 20000mg/L total salinity, Ca2+and Mg2+concentration of 364 mg/L and 136mg/L respectively. The simulated enhance oil recovery(EOR) results of polymers at 80°C in the solution of 20000mg/L total salinity, Ca2+ and Mg2+ concentration of 364 mg/L and 136mg/L respectively showed that SPAM reached 11.8% EOR basis on the water flooding(41.1%), compared with CSPAM flooding and HPAM flooding, the EOR with SPAM flooding was increased by 7.4%and 6.8%, respectively. In order to futher study of the performance of SPAM, The simulated enhance oil recovery(EOR) of SPAM was implemented at 80°C in the solution of 80000mg/L total salinity, Ca2+ and Mg2+ concentration of 728 mg/L and 272 mg/L respectively.SPAM chemical flooding recovery degree was 10.7%, compared with the above test, the oil displacement was not affected more, which reflected a good prospect of oil displacement.y=a×xb equation was established to describe the relationship between salt ion concentration and apparent viscosity of the polymer solution through the polymer salt resistance test,analysis and data fitting. The mechanism of salt ions affect on the apparent viscosity of polymer are analyzed and discussed.The anti-aging properties of the polymer was investigated at 80 °C in the solution of total salinity of 20000 mg/L above, the results showed that the apparent viscosity of the solution of SPAM from 20.0 m Pa?s fell to 15.1 m Pa?s after 90 days, viscosity retention rate was 75.5%.The composite system of ethylene glycol and thiourea was used in the tests and the results showed that the viscosity retention rate of 86.5% was much greater than the viscosity retention rate(62.5%) of not adding the anti-aging inhibitor in the solution of total salinity of20000 mg/L above at 110 °C.