The effect of polymer type on the performance of gels

Abstract

Owing to the formation heterogeneity, the difference of mobility between sweeping phsse and formation fluids, gravity segregation, the sweeping phase usually flows along the high permeability zone, which leads to the poor oil recovery. In general, gelling systems are used into the reservoir conformance improvement. The properties of gels are different for the different composition of gelling systems. In this paper, three polymers with different AMPS content were used to investigate the effect of polymer type on the performance of polymer gels. In addition, methenamine(MA) and hydroquinone(HQ) were employed as crosslinkers, thiourea(TH) was used as oxygen scavenger to improve the stability of polymers and gels. And the gelation time, strength and syneresis rate of gels were characterized respectively. The results showed that the stability of polymer and gel was enhanced with the increase of AMPS content, and the gelation time was increased with the increment of AMPS content. And an ultrastable thermal-resistance and salt-tolerance gel was developed with the AM/AMPS copolymer (AMPS content equals 70%), the syneresis rate was less 10% after heat treatment under the harsh conditions (temperature=130°C, salinity=223802.8mg/L) for 150 days.