The Physical Simulation Of Enhancing Oil Recovery Of Heterogeneous Reservoir Of Heavy Oil By Binary Flooding

According to the current oilfield development demand, the chemical flooding technologyhas been actively introduced by offshore heavy oil field. The oil field opened up a multipleexperimental blocks to conducting pilot test for polymer flooding and made a great ofachievements.At present, a lot of research have been performed on improving oil recovery bycomposite flooding at home and abroad. However, the study of binary compound flooding inoffshore oil field is less. Therefore, in order to meet the needs of further improving oilrecovery after polymer flooding, the research of binary to improve oil recovery after polymerflooding is particularly important.For the above problems, this paper carried out a series of research work. Firstly, thepaper studied the relationship between oil saturation and the resistance value of heavy oil onbase of comprehensive consideration of influencing factors of measuring resistance valuesuch as formation water salinity, core permeability, chemical etc. More complete resistance-saturation curves have been established by displacement method which used unit grid core.On the basis of the above, displacement experiments of two-dimensional plane, vertical andthree-dimensional simulation model of heterogeneity were carried out that met thecharacteristics of reservoir in offshore oil field. Then compared the seepage field changes ofdifferent displacement stages and studied the improved oil recovery effect of binarycomposite flooding.The results show that the vertical heterogeneity of offshore oil reservoir is stronger, andinfluences the effect of water drive.0.3PV polymer slug is injected in the experiment. Theinjection of polymer slug increases the flow resistance, improves the reservoir displacementpressure, and adjusts the fluid producing profile and the heterogeneity on the plane andvertical. Oil wall is formed in the different permeability layers, which mainly expands sweepvolume on middle permeability layer. The binary system main function is to reduce theinterfacial tension of crude oil, to displace the remaining oil out of the affected area of eachpolymer layers and greatly improve the oil displacement efficiency, and to enlarge the sweptvolume of low permeability layer. Low permeability layer surface on both sides of themainstream line was swept. The swept area is increased by40.14%compared with waterflooding stage. The potential role of binary composite system lies in the low permeableformation, improve the oil displacement efficiency in each layer and greatly improve therecovery efficiency on the basis of polymer flooding.