Electrocoalescence Behavior of Two Drops Containing Hydrolyzed Polyacrylamide and Sodium Dodecyl Sulfate*

Enhanced oil recovery (EOR) techniques are crucial for extracting additional oil from underground reservoirs. Chemical-enhanced oil recovery involves injecting surfactants and polymeric water, which form stable emulsions during oil production. However, separating the injected fluids is essential to prevent issues in refineries. In our study, we investigated the coalescence behaviour of surfactant (sodium dodecyl sulfate, (SDS)) and polymer (hydrolysed polyacrylamide, (HPAM)) containing aqueous droplets in an insulating oil under a fixed, uniform electric field. We also studied the impact of brine (5000 ppm) on these droplets. The main findings of this study are as follows: We derived expressions for the critical capillary number (CaE) versus concentration for SDS and HPAM-containing aqueous droplets. Notably, the CaE decreases with increasing concentration for SDS, HPAM, and their combination in the absence of brine. For brine-containing drops, SDS and a combination of SDS and HPAM show CaE increase as the concentration rises, while CaE for HPAM remains unchanged. 

This work was supported by the Science and Engineering Research Board (SERB) India (Grant No. : SRG/2021/000275) and the Indian Institute of Technology Jodhpur (IITJ).