DSC Investigation of the Gelation Kinetics of emulsified PAM/PEI System: Influence of different surfactants and retarders

摘要

Polymer gels are commonly utilized for water shut off in oil and gas wells. A mobile oil phase is generally used to emulsify an aqueous polymer gels. The breaking of the emulsified system and then the gelation are a function of temperature, time, salinity of mixing water and concentration of the different components including surfactants and salts. In this study, the gelant was prepared by mixing polyacrylamide (PAM) with filed mixing water, and then polyethylenimine (PEI) was added as a cross-linker. Diesel and surfactant were used to form the emulsified gel. The injection process was replicated and examined by differential scanning calorimeter (DSC). The separation and gelation phenomena and its kinetics have been studied via differential scanning calorimeter (DSC). Additionally, the impact of different parameters such as temperature, water salinity, and surfactant and retarder type on the gelation development was investigated. Conclusively, a kinetics comparison between the polymeric gels and its emulsified form has been done. At a given emulsifier concentration, emulsified PAM/PEI was found to have lower rate of cross-linking (gelation) in comparison with PAM/PEI due to the partial dissolution of the cross-linker in the oil phase. Ammonium chloride was found to be more efficient than sodium chloride in the retardation of the gelation process.