Development Of High Temperature Gel For Channeling Plugging In Heavy Oil Thermal Recovery

Steam channeling usually happens in the later cycles of steam stimulation stage,and leads to interwell steamchanneling interference,then,the recovery becomes worse.To solve this problem,alkali lignin gel,which is resistant to 200?,and tannin gel,which is resistant to 250?,were developed.Basic alkali lignin gel formula was 8% alkali lignin +1% phenolic cross linker CL1+2.75% aldehyde cross linker CL2.It gels within 50~3.5h,at 80~200?,gel strength is 0.070~0.090 MPa,after 30 days at 200?,the gel dehydration rate is less than 10%.Basic tannin gel formula is 6%tannin+0.8% phenolic accelerator AC1+1.0% aldehyde cross linker CL3,p H is 7.It gels within 18~1.5h,at 60~250?,gel strength is 0.080~0.090 MPa,after 30 days at 250?,the gel dehydration rate is less than 40%.In order to further improve the performance of alkali lignin,alkali lignin-polymer composite gel was developed,so that the original alkali lignin gel became more viscous and more stable at high temperature.and was studied by micro analysis.After the static evaluation of the two kinds of gels was finished,physical simulation experimental method was used.Plugging effects of the gels and different combination of plugging agents were evaluated.The experiment result proved that segment combinations such as polymer gel+alkali lignin gel+cation polymer gel,emulsified asphalt+tannin gel+emulsified asphalt,had good channeling plugging effect.