Temperature Salt Hydrophobically Associating Polymer Deep Profile Control System Study

According to the instability of Hydrolyzed Partially Polyacrylamide (HPAM) deep profile control system at high temperature and salinity, a new way, which is used to tolerance temperature and salinity, is suggested, that is taking full advantage of the association of hydrophobic groups between molecules in the Hydrophobically Associative Polymer(HAP) molecules, which is thought as cross-linking action, is to increase the counts of cross linked point between inter-molecules. Because the cross linking strength resulted from association is less than that of the chemicals while the cross linking strength is decreased obviously, the dehydrating action and velocity of HAP weak gel system is lower greatly or even disappear. Thus the instability of HPAM profile control system on the condition of high temperature and salinity can be solved favorably.Firstly, in this paper the theory of the molecular frame of HAP is discussed, on the contrast of the difference in molecular construction between HAP and HPAM, the mechanism of the HAP weak gel system is analysed. On the condition of the reservoir characteristics of high-temperature and salinity of Wei 305 block , in Zhongyuan oil field, the weak gel system of HAP was screened. The associative polymer concentration in the gel system is from 3000 to 3500 mg/1, the cross-linking agent is 32~79 mg/1. The stability , the shear tolerance , the changes of section and injection pressure before and after injection of the gel system and ths core performances were evaluated in lab at the temperature of 95 癈, in all experiments produced brine(salinity is 170,000 mg/l)is used as dilution brine. The injecting project of polymer profile control for 305 block is that the polymer concentration is 3500mg/l, cross-linked system is urotropine0.0549%+ oxalicacid0.1l 2%+ pheno10.054%+isophthalic ester0.0115%. The performances of weak gel treatment are forecasted using numerical simulation FAPMS. The increase of oil over water flood recovery is 0.6025%, the cumulative oil increases 6446 tons or 581 ton per polymer. So the project is economical after the weak gel treatment by primary analysis.