Cementing in deep and ultra-deep reservoirs often faces the critical challenge of additive degradation in high-temperature environments.Addressing this,1-vinylimidazole(VM)was incorporated into the copolymerization of...Cementing in deep and ultra-deep reservoirs often faces the critical challenge of additive degradation in high-temperature environments.Addressing this,1-vinylimidazole(VM)was incorporated into the copolymerization of N,N-dimethylacrylamide,itaconic acid,and 2-acrylamido-2-methylpropanesulfonic acid to synthesize a tetrapolymer(PDVI).Using aqueous free radical polymerization optimized by response surface methodology,the resulting PDVI exhibited superior fluid loss reduction in hightemperature and high-salinity conditions.Compared to the control sample PDI,PDVI reduced fluid loss from 64.7 mL to 25 mL at 200℃ and from 105.7 mL to 42.5 mL at 240℃,while maintaining filtration below 70 mL in 20%NaCl.Structural characterization via ^(1)H NMR and FTIR,combined with TGA and aging tests,confirmed that VM's rigid five-membered ring significantly enhanced thermal stability;molecular weight retention after aging at 220℃ increased from 46.13%to 68.31%.Furthermore,DLS,SEM,and zeta potential analyses indicated that VM's cationic nature facilitates robust polymer adsorption on cement particles.This mechanism ensures effective particle dispersion and the formation of a dense filter cake even under extreme conditions.These findings provide essential insights for developing high-performance polymeric additives for cementing in complex downhole environments.展开更多
基金supported by Project of Basic Science Center of National Natural Science Foundation(No.52288101)the Fundamental Research Funds for the Central Universities(23CX05001A).
文摘Cementing in deep and ultra-deep reservoirs often faces the critical challenge of additive degradation in high-temperature environments.Addressing this,1-vinylimidazole(VM)was incorporated into the copolymerization of N,N-dimethylacrylamide,itaconic acid,and 2-acrylamido-2-methylpropanesulfonic acid to synthesize a tetrapolymer(PDVI).Using aqueous free radical polymerization optimized by response surface methodology,the resulting PDVI exhibited superior fluid loss reduction in hightemperature and high-salinity conditions.Compared to the control sample PDI,PDVI reduced fluid loss from 64.7 mL to 25 mL at 200℃ and from 105.7 mL to 42.5 mL at 240℃,while maintaining filtration below 70 mL in 20%NaCl.Structural characterization via ^(1)H NMR and FTIR,combined with TGA and aging tests,confirmed that VM's rigid five-membered ring significantly enhanced thermal stability;molecular weight retention after aging at 220℃ increased from 46.13%to 68.31%.Furthermore,DLS,SEM,and zeta potential analyses indicated that VM's cationic nature facilitates robust polymer adsorption on cement particles.This mechanism ensures effective particle dispersion and the formation of a dense filter cake even under extreme conditions.These findings provide essential insights for developing high-performance polymeric additives for cementing in complex downhole environments.
