Assessment Of Gel System For Chemical Water Shut-off On H1 Block Of Liaohe Oilfeild

In recent years, with the increasing recovery percent and expanding flooded area, the application effect of profile control water shut-off agent has declined year by year. Although carried out the corresponding plugging control and expanded the treatment radius, the application effect had obviously deteriorated. Moreover, these application technologies were lack of laboratory study report and the adjustment of water shut-off was short of theoretical guidance. Therefore, through laboratory study, determined series water shut-off technology meeting the present exploitaion situation of oil field to guide the field practice and provide strong technical support of oil field exploitation in high water-cut stage.According to the development situation of H1 blcok in LiaoHe oilfield ,the thesis selected four water shut-off agent systems which were using there, conducted static and dynamic evaluation experiments respectively and simulated the injection process, the results showed: the gelation time and the gelling strength of phenolic resin gel system and urea-formaldehyde resin gel system can be controlled.According to the selecting formula of static evaluation, determined the breakthrough pressure and other parameters in different gel system by core experiments, optimized the injection scheme of each gel system and then ascertained the water shut-off injection scheme of Haiwaihe oil field. The resistance coefficient, breakthrough pressure gradient and water shut-off rate of phenolic resin gel system and urea-formaldehyde resin gel system in various core permitility were different.As the permitility increasing, the resistance coefficient declined, the breakthrough pressure reduced and the water shut-off rate changed slightly.Phenolic resin gel system and urea-formaldehyde resin gel system conducted one runs water shut-off in non-homogeneous cores, the water shut-off rate was more than 73.2% and the recovery ratio was more than 18.8%; conducted one runs in three parallel cores, the water shut-off rate in high permitility formation was more than 99% with the recovery ratio 14.9%.Both systems had good washing resistence.Through the experiment of injection technology on three paralleled cores, the effect of injection mode and injection multiple runs on oil displacement was analyzed,and got the conclusion of: the injection mode of from big to small was better than that of from small to big, and the effect of different layer injection was better than that of injection in the whole.