Low temperature applicable cyclic sulfonium functionalized poly(vinylbenzyl chloride) (PVBC) electrolyte gelator for partially hydrolyzed poly(acrylamide) (HPAM) in situ gel is described herein. Addition of polyelectrolyte gelator to HPAM generated covalently crosslinked in situ gels through formation of ester crosslinks under reservoir conditions. The generation of covalent crosslinks through chemically nucleophilic attack by carboxylate groups tethered to HPAM backbone to sulfonium moieties was demonstrated by corresponding spectra analysis of nuclear magnetic resonance (NMR) and rheological studies. Compared to high temperature phenol/formaldehyde and poly(ethyleneimine) gelator system, the gelation of PVBCTHt polyelectrolyte gelator and HPAM occurred over a broad range of temperatures from 25 to 80 degrees C. At 25 degrees C the gelation of PVBCTHt gelator and HPAM was significantly delayed to weeks compared to Cr3+-HPAM system having fast gelation kinetics in 6 h. Due to its delayed gel formation over weeks at room temperature, the gel could be deployed for in-depth reservoir treatment. The gelant showed excellent salt and pH resistance under reservoir conditions as reflected by mechanical integrity of in situ bulk gel. Core flooding experiment on sandpack demonstrated the gel could efficiently divert brine flow for conformance control, which displayed better plugging efficiency than Cr3+-HPAM system.