Behavior study of a thermo-responsive hydrophobically associative water-soluble terpolymer in laboratory test with heavy crude oil

摘要

In this work, a thermo-responsive hydrophobically associative water-soluble terpolymer was prepared and evaluated as polymer flooding in laboratory tests versus a heavy crude oil from a carbonated reservoir in southern Mexico. Terpolymer of acrylamide, N-isopropylacrylamide and N,N '-dihexylacrylamide were synthesized via micellar free radical polymerization. Reaction was carried out at 50 degrees C using sodium dodecyl sulfonate as surfactant and 4-(4 '-azobis)cyanovaleric acid as initiator. The terpolymer was characterized by nuclear magnetic resonance. Steady shear viscosity of polymer solutions at different concentrations was determined in the presence of NaCl (from 1 to 5 wt%) at different temperatures (from 25 to 120 degrees C). Heavy crude oil sample was characterized and revealed a viscosity of 2. 26 Pa s, 10.21 degrees API with a content of Saturates, Aromatics, Resins, Asphaltenes of 26.4, 38.5, 22.3, and 12.8, respectively. The crude oil recovery of polymer at 2 and 3 wt% revealed a surface tensions of 49.6 and 48.2 mN x m and adsorption capacities of 1.33 and 1.77 wt%. Finally, polymer solutions at 2 and 3 wt% showed a contact angle between 29.6 and 26.5 degrees and a crude oil recovery of 68.3 and 75.3%, respectively.