Characterization of Oilfield High Molar Mass Polymers Under Different pH and Mono-Di Valent Ion Environment Using Asymmetrical Flow Fluid Flow Fractionation

• Author / Creator

  Dalsania, Yogesh Kumar T

• Various types of ultrahigh molar mass polyacrylamides (PAMs) or HPAMs and their co- and ter-polymers used not only in enhanced oil recovery, but also in drilling, fracturing, water treatment and tailing applications require an accurate description of polymer molar mass (Mw) and hydrodynamic size for their optimal design. Molecular weight distribution (MWD) cannot be determined since either standard with low PDI, nor GPC/SEC techniques exist today for such ultrahigh molar mass polymers. Moreover, the solution environment in underground reservoirs, characterized by high temperatures, pH and the presence of monovalent and divalent ions, may often lead to changes in polymer macromolecular conformation. In this study the Asymmetrical Flow Field Flow Fractionation (AF4) system was utilized to fractionate ultrahigh molecular weight HPAM samples, varying in molar mass and commercially used for oilfield applications, in various carrier pH values ranging from 12 to 3 (pH 12, pH 7.4 and pH 3). In the second part of study effect of mono valent and di valent ion (salinity ranging from 1000 ppm to 10000 ppm) was investigated on post hydrolyzed, co polymer and associative polymer of PAM. The results show that the observed molar mass of the polymer aggregate increased substantially as the pH of the carrier solution decreased from 12 to 3, especially for higher molar mass polymers. The samples radius of gyrations showed the opposite trend decreasing as the pH of the carrier solution changed from basic to acidic. The observations show that the molar mass value of polymer aggregate decreases as salinity (monovalent ion) of the brine increases, similarly radius value also decreases as salinity increases. Di-valent ion has significant impact on radius of the polymer aggregate. A 31% decrement in radius values is observed as ions changes from Na+ to Ca2+ at same salinity.

• Subjects / Keywords

  • AF4-MALS-RI
  • AF4
  • EOR Polymers
  • HPAM
  • High Molar Mass Polymer Charaterization

• Graduation date

  Spring 2017

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3QZ22V8P

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.