Three separate injection technologies for different stages of development are developed in Daqing oilfield

including concentric separate-injection

eccentric separate injection

and separate-layer molecular injection.The concentric separate-injection technology controls injection rate of each layer by using concentric injection allocator which regulates injection pressure.The eccentric separate injection technology controls injection rate of each layer by using eccentric injection allocator to generate enough differential choke pressure to regulate injection pressure.The separate-layer molecular injection weight technology controls injection rate of each layer by using molecular weight regulator or pressure regulator chosen according to reservoir property.This paper described in-detail their process principles

technical parameters

application scale and their effects et al.According to the actual stages of polymer injection in the oil field

this paper presents the rational timing and principles of separate injection as well as the corresponding test cycles.In addition

the principles for selection of separate injection technologies are also proposed according to the types of pay zones.Short clamping distance of the polymer injection technology and efficient measurement technology of separate injection wells in the polymer flood oilfield are the key research direction in Daqing oilfield.