The Second Class Reservoir Microscopic Remaining Oil Change Rule After ASP Flooding

Daqing oilfield since 1960, most of the blocks has entered high water cut stage effluence. North area east based pattern after water injection, well network encryption production phase and polymer chemical flooding stage, is faced with the problem of high water cut again. The asp flooding technology can play a positive role in stabilizing oil water control, therefore block the asp flooding technology to enhance oil recovery. According to the characteristics of the second class reservoir property study under the condition of different displacement solution, after asp flooding pore distribution of microscopic remaining oil occurrence state, residual oil content in the components and residual oil distribution state. Can not only realize after asp flooding state microscopic remaining oil in reservoir pore regularity of visualization, but also can provide with specific significance for subsequent mining theory and data base.In view of the second class reservoir of Daqing oilfield, the change rule of residual oil after asp flooding in this paper, we selected 300×10-3μm2, 500×10-3μm2 and permeability in three layers within the scope of the second type reservoir heterogeneity core as the research object. Through the indoor experiment study: The ternary system displacement, remaining oil saturation and residual oil components and residual oil types by permeability and capillary number, and the effect of permeability differential. In the case of different permeability, the permeability of the size of residual oil saturation index and the content of each type of remaining oil, light and heavy components change all play a role, at the same time, through the detection corner of residual oil content changing with the permeability volatility is larger. In this paper, we study capillary number in 10-3 ~ 10-1 cases on the effects of the displacement and residual oil saturation and remaining oil component index and decreases as the number of capillary. At all levels after the number of capillary displacement corner shape of remaining oil in cores in the remaining oil types, the largest proportion of followed by clusters of, throat residual oil, film hole table minimum residual oil content. It is not difficult to find that the capillary number, the greater the various types of residual oil content. Oil displacement effect and the permeability differential, the average permeability and permeability rhythm combination has a lot to do, the greater the differential permeability, low permeability layer did not use the residual oil content, the greater the average permeability, the greater the residual oil in every layer are less, along the length of remaining oil saturation component index and weight all have certain influence. Through the test data shows that due to the differential permeability and permeability rhythm combination is different, each layer of the residual oil content of the four types also have very big difference. Corner shape of remaining oil still proportion is the largest, followed by clusters of remaining oil, throat remaining oil, film hole table minimum residual oil content.