Study On Selective Local Plugging Technology Of Multi-Layer Production Wells In Bohai Oilfield

Binary compound flooding is a more effective tertiary oil recovery method,which has a good effect to improve the production of oil field.However,in the process of binary displacement,the phenomenon of channeling occurs in some heterogeneous formations,which makes the displacement efficiency decrease.In order to further improve the efficiency of binary displacement,it is necessary to adjust the channeling formation.This paper takes the Bohai oilfield block as the research object,and puts forward the technical route of blocking the blocking by using the polymer which is residual in the pore of the rock in the process of binary system displacement.Through the flocculant screening experiment,the plugging agent which can make the residual polymer flocculation in the pore of rock is developed.Through the core simulation evaluation experiment,the injection parameters of the flocculant are optimized.The results show that the selective local plugging technology after the target binary compound flooding can improve the sweep efficiency and the sweep efficiency of the displacement liquid,and further improve the oil recovery ratio.The best flocculant formula: 0.7 % zinc chloride(Zn Cl)solution;The volume PV of the optimal positive injection flocculant: 0.6;The optimal size of the inverted injection flocculant is: 0.6 PV.Two conclusions can be drawn from the full text: First,the development situation in the Bohai Sea region is severe,and it is necessary to introduce the chemical flooding method for three times oil extraction.Second,the cationic solution will be injected into the formation and the polymer to produce flocculation bodies to achieve the reuse of the residual polymer in the formation.Third,the application of the flocculant is also applicable to Daqing Oilfield where polymer flooding is carried out.