Preparation And Evaluation Of Temperature Resistant Foam Gel

Foam gel is a dispersed system composed of gas distributed in the gel.As a new type of profile control agent developed on the basis of water-based foam and gel,foam gel has the advantages of low liquid volume,low price,high efficiency,good elasticity and moderate strength.Foam Gel combines the plugging characteristics of water based foam and polymer gel.The polymer solution foam stage has the property of water-based foam,which can selectively block in the reservoir.At the same time,the strength of the gel liquid membrane in the foam gel structure is high,so that the foam structure is not easily broken.Therefore,the foam gel has better plugging performance on the basis of the foam effect of Jamin.However,in the actual production process of oilfield,the conventional foam gel system has poor stability when applied to high temperature reservoirs.In this paper,a new type of temperature resistant foam gel has been developed.The rheology and stability of foam gel system and its influencing factors have been studied by Haake rheometer and Brinell viscometer.The microstructure of foam gel system has been observed by SEM.The results show that KYPAM-5SH,complex crosslinking agent II and CAB-35 are suitable for polymer,crosslinking agent and foaming agent of foam gel system,proper amount of deoxidizer and foam stabilizer can increase the stability of foam gel system.The formulation of the temperature resistant foam gel system was as follows:0.3 wt% KYPAM 5SH+0.245 wt% cross-linking agent A+0.0348 wt% crosslinking agent B+0.075 wt% CAB-35+3 wt% foam stabilizer + 0.4wt% deoxidizer.With the increase of temperature,the viscosity of the gel that keeps the stability of the foam gel is increasing.And the viscosity of the gel reached 12000 m Pa·s at the temperature of80 ? and salinity condition of 10000 mg/L Na Cl.In normal temperature,the viscosity of the foam gel system increased with the increase of polymer concentration and crosslinking agent concentration,the viscosity of the system decreased slightly with the increase of the foaming agent concentration,the viscosity of the system increased first and then decreased with the increase of the concentration of the foam stabilizer,theconcentration of the deoxidizer had no obvious effect on the viscosity of the foam gel system.The proper addition of polymer,crosslinking agent,foam stabilizer and deoxidizer concentration is beneficial to the stability of foam gel,the increase of foaming agent is not conducive to the stability of foam gel.The stability of the foam gel was good at 100 ? and 10000 mg/L Na Cl,the half-life was 10 days.The foam gel system formed a network gel structure,thereby enhancing its temperature resistance.