Smart Profile Control by Salt-Reversible Flocculation of Cationic Microgels and Polyacrylamide

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• 作者：Guanghui Li ; Guicai Zhang ; Lei Wang
• 刊名：Energy & Fuels
• 出版年：2013
• 出版时间：November 21, 2013
• 年：2013
• 卷：27
• 期：11
• 页码：6632-6636
• 全文大小：286K
• 年卷期：v.27,no.11(November 21, 2013)
• ISSN：1520-5029

文摘

A flocculation system is detailed to deal with the size matching problem between pore throats and microgels for profile modification in high permeable formation. This system consists of partially hydrolyzed polyacrylamide (HPAM) and cationic microgels synthesized by inverse suspension polymerization with acrylamide and methylacryloxylethyl trimethyl ammonium chloride as monomers. By adding HPAM into cationic microgel suspensions, flocculation occurs because of electrostatic attraction. Then it reversibly restructures from bulk to an insulated microgel particle at a critical salt concentration (CSC). In the profile modification test, this flocculation system diverts nearly 100% chase water into the low permeable tube compared to 20% by using microgels only. The performance improvement testifies the mechanism that HPAM flocculates around the cationic microgels to make up the interstitials between microgels and irregular pore throats. This flocculation plug can be removed by water with salinity above CSC due to the desorption of HPAM on cationic microgels.