Investigation of Rheological Properties and Performance of Polymeric Gel Systems (Based on Polyacrylamide) in High Temperature Reservoirs

In this research, polyacrylamide based hydrogels were made on the basis of solvent method, and their rheological properties and performance were evaluated by bottle testing and a rheometer under Iran south oil reservoir conditions. Based on the results of the bottle test, the polymeric gel formed by 15000 ppm polyacrylamide and 2500 ppm chromium (III) acetate and kept at 90 °C for 24 hrs was selected as a basic polymeric gel. Based on the results of rheometric tests at temperature of 25°C, the elastic modulus almost remains constant in frequency range of 0.1 to 10Hz and the strain range up to 100%, whereas this module decreases from 8 Pa at 25 °C to 4 Pa at 90 °C. Studying the effect of the applied yield stress on the polymeric gel indicates that for a sample each of three strain points of 100%, 3280%, and 6470% could be considered as a yield point, but it could not be found decisively because of wall slip effect around the rheometer wall. Also, the polymeric gel system does not tear up to the strain of 6470% and the elastic properties are superior to the viscous nature of the system below this point