Comb-type polymeric additives as flow improvers for crude oil with high asphaltene and wax contents

During the extraction and transportation of crude oil, several operational problems are caused by paraffin deposition when temperature drops to wax precipitation temperature, which pose serious safety risks and ultimately cause huge economic losses. However, this issue can be mitigated by treating crude oil with additives comprised of polymers having comb like structures. In this study, starting from the molecular structure of pour point depressants, a series of pour point depressants with different molecular structures were synthesized. By regulating the molecular composition of the terpolymer and adjusting molecular properties such as the polarity of the pour point depressants, their effects on performance were compared. The designed PPDs having weight-average molecular weights ranging between 21131 and 33411 were characterized by FTIR and 1H NMR to gain structural insights. By using polarizing microscope, rotary rheometer, and differential scanning calorimetry, the wax morphology, rheological behavior and crystallization temperature of crude oil were studied after beneficiation with polymeric additives. The optimal performance achieved by copolymer with decreasing pour point amplitude by 17 degrees C and viscosity reduction by 99.03% at 20 degrees C respectively using PPD dosage of 1500 ppm.