Can CDG Gels Flow in Porous Media with Permeabilities Less than 8 Darcys?
The Controversy February 2006 JPT.In the February 2006 issue of the Journal of Petroleum Technology (JPT) H.L. Chang et al.1 summarized some of the pilot and commercial-scale field activities on polymer flooding and ASP flooding that were performed in China. Unquestionably, polymer flooding and ASP flooding can be effective oil-recovery processes and have great potential. Unfortunately, the paper also advocated a controversial technology (flooding with aqueous colloidal dispersion gels) as being superior to polymer flooding. This claim is misleading and generally incorrect. “Colloidal dispersion gels” (“CDG” or relatively low concentrations of HPAM crosslinked with aluminum citrate) should not be applied without carefully examining the purported science and engineering behind this process. Chang and the CDG vendor that he represents speculated that low-concentration aluminum-citrate-HPAM micro gels propagate through porous rock like super polymer solutions.1-4 Specifically, they sugges
