At the time of his death in 2009, Robert D. Sydansk was a consultant specializing in enhanced oil recovery, improved oil recovery, and conformance improvement, with special emphasis on polymer-gel use for water shutoff and sweep improvement. Prior to 2000, he worked for 33 years at Marathon Oil Company’s technology center, where he conducted R&D in nearly all phases of chemical improved oil and gas recovery. During his latter tenure at Marathon, he developed the chromium carboxylate/acrylamide polymer (CC/AP) gel conformance-control and fluid-shutoff technology. Sydansk was the author or coauthor of more than 40 technical papers and contributed a chapter on the use of polymers, gels, foams, and resins to the 2007 edition of SPE’s Petroleum Engineering Handbook. He is the inventor or co-inventor of 60 U.S. patents and more than 130 international patents within the same technical area. Sydansk graduated from the University of Colorado with a bachelor’s degree in chemistry and minors in mathematics and psychology; he was a 1997–1998 SPE Distinguished Lecturer for SPE and was selected as a Distinguished Member in 2000.

Laura Romero-Zerón is a chemical engineer who is currently an Associate Professor in the Chemical Engineering Department at the University of New Brunswick. She was previously affiliated with the Research and Development Center of Petróleos de Venezuela (PDVSA), where she worked for more than 6 years as a research scientist in the area of enhanced oil recovery. Romero-Zerón holds a PhD degree in chemical and petroleum engineering from the University of Calgary. Her research interests include optimization of EOR chemical flooding, evaluation of the mechanisms of polymer gels as conformance-improvement agents, heavy oil recovery, and bitumen upgrading. Romero-Zerón has published more than 26 papers in refereed journals; she is a member of SPE and holds the SPE Petroleum Engineering Certification.