Experimental Study Of EOR In TH Heavy Oil Reservoir By CO₂/Flue Gas Injection

The permian reservoir of LKQ oilfield belongs to deep seated heavy oil with strong heterogeneity glutenite reservoir,there are impact factors such as water sensitivity,high crude oil viscosity,low dissolved gas,during the development of water injection,water breakthrough is fast and oil displacement efficiency is low,in view of the practical problems of this kind of development,this paper adopts the method of physical experiment simulation on the basis of investigating the domestic and foreign literatures This paper analyzes the mechanism of injecting CO₂/flue gas to improve the recovery of heavy oil,the feasibility of gas injection and the the optimal mining method.I completed the rock property evaluation,reservoir phase characteristics evaluation,characteristics of gas injection evaluation,water flooding and gas flooding seepage features,reservoir sensitivity evaluation of gas injection and the analysis of reservoir gas injection effect in this paper,then get the following conclusions and recommendations:1)Through the analysis of porosity and permeability characteristics,aimed at the poor development of pore throat structure in some cores of the reservoir,the way of making artificial fissures can be used to increase the percolation capacity of crude oil.2)Through the analysis of characteristics of seepage,core gas oil displacement efficiency medium,suffer indignities and immiscible gas flooding process significantly greater than the effect of liquid phase flow degree.The two-phase flow resistance of gas drive is obviously smaller than that of water flooding.Immiscible flooding caused by gas injection is easy to occur,after breakthrough by increasing gas injection to enhance oil recovery plan is not workable.3)Through a deep heavy oil reservoir formation fluid phase state and gas injection expansion compatibility experiments,CO₂ and flue gas were not in the proper pressure range and deep heavy oil miscible.The CO₂ has better compatibilizing effect of viscosity reduction than flue gas of deep heavy oil.4)Through four long core gas injection flooding and water flooding experiment,under the condition of the same displacement ratio,the efficiency of water drive oil displacement is higher the flue gas,but lower than that of CO₂ flooding oil displacement efficiency,that is for deep heavy oil reservoirs,CO₂ flooding effect is the most ideal.5)Through gas injection and physical experiment of different development mode selection,choose the earlier stage in gas injection development,maintain a relatively high pressure and adopt the reasonable gas injection rate can effectively improve the deep heavy oil recovery.Additional water flooding development in low moisture content of timing or by water alternating gas injection and gas injection slug can obtain better than pure water flooding development effect.After failure of CO₂ stimulation method does not have ideal effect.