Novel self-assembling polymeric system based on a hydrophobic modified copolymer: formulation, rheological characterization, and performance in enhanced heavy oil recovery

This work presents the chemical formulation and rheological properties of a novel self-assembling polymer (SAP) system derived from a hydrophobically modified sulfonated polyacrylamide (HMSPAM). This polymeric association was established through complexation between the pendant hydrophobic groups contained in HMSPAM and -cyclodextrin molecules. The new SAP system offers improved viscoelastic properties because of the interlocking effect of the hydrophobic groups into -cyclodextrin cavities. It also provides suitable reformability upon mechanical shear when compared to the base HMSPAM. Furthermore, SAP exhibits superior tolerance to elevate brine salinity and hardness, as well as high reservoir temperature. Sandpack flooding tests conducted at simulated reservoir conditions (Pelican Lake reservoir, Alberta, Canada) indicate that this system shows superior mobility control (resistance factor) compared to HMSPAM. It also shows potential as in situ permeability modifier, which makes this polymeric system particularly suitable for heavy oil recovery applications. For instance, the newly developed SAP produced 20% more incremental heavy oil recovery if compared to the performance of the commonly used partially hydrolyzed polyacrylamide and 7% more incremental oil recovery than the baseline HMSPAM at the same experimental conditions. Overall, this new self-assembly system shows potential for applications in heavy oil recovery. Copyright (c) 2014 John Wiley & Sons, Ltd.