| Partially hydrolyzed polyacrylamide (HPAM) is widely used in polymer flooding and got a good economic and social benefit. Due to its poor temperature and salt tolerance, HPAM is not suitable to be used in high-temperature and high-salinity reservoir. In allusion to the characteristics of high-temperature and high-salinity resevior, polymerization of AM and 4 monomers with sulfonic acid group was carried respectively. And the polymer with best viscosity was chosen. Orthogonal test was carried to determine the optimal condition of polymerization. Effects of time, temperature, monomer concentration, monomer compound, the amount of initiator and drying temperature on the polymer's viscosity were investigated. The Sulfonated polyacrylamide (SPAM) was composed under those conditions. IR spectrums of HPAM and SPAM can explain their structures. Limiting viscosity of SPAM was tested by viscometer, and then its molecular weight was calculated as 5.15×106. Compare to HPAM, the excellent solubility, thickening property, temperature and salt tolerance of SPAM were indicated by experiments. SPAM can satisfy the requirements of high-temperature and high-salinity reservoir. To improve the molecular weight of SPAM, crosslinking of SPAM and different cross Linkers were taken and the proper cross linker was selected. When the polymer addition was 500mg·L-1 and phenol/formaldehyde crosslinker concentration was 1000mg·L-1, the viscosity of crosslinking system increased greatly and reached to 172mPa·s at 60℃with a good rheology. Effect of sulfonated polymer's structure on its temperature and salt tolerance approved that, the incorporation of the sulfer acid radial in polymer backbone of HPAM results in excellent properties of the copolymers such as improved resistance to temperature and improved salt tolerance. The research provides foundation and important reference database for the application of sulfonated polyacrymides in polymerflooding.
|
PDF Full Text Request