The Property Variations of Produced Polyacrylamide from Polymer Flooding Reservoirs and Their Effects on Concentration Detection

Because the injected polymer (polyacrylamide) often quickly breaks through to production wells during polymer flooding, its concentration detection is very significant. However, due to the variations in the relative molecular mass and the degree of hydrolysis of produced polymer, the conventional detection methods, including the viscosimetry and starch-cadmium iodide colorimetry, are no longer suitable to detect its real concentration. This paper introduced a new detection method-ultrafiltration concentration film\u27s desaturation. By purifying and concentrating the produced polymer solution using an ultrafiltration system, then dehydrating the aqueous and dry up the remains, this method can detect the concentration directly. The said method has been evaluated in the laboratory and compared with the other two conventional detection methods, verifying its adaptability and high exactitude. The produced polymers from three different polymer flooding units have been detected using this novel method. The results show that the produced polymer relative molecular mass decreased greatly but its degree of hydrolysis increased obviously. The reasons and differences have been analyzed. These corresponding variations makes the detected results by the conventional methods be much lower than the actual, meaning that the previous methods need to be improved or replaced