An Investigation On The Three-phase Foam Flooding Technique Of Enhanced Oil Recovery In Block A Water-Drive Reservoir

Block A is mainly of sandstone reservoir,with serious reservoir heterogeneity.The high speed exploitation in the early development stage result in relatively fast growth of water-cut,and the entire Block A have entered into the phase of high water-cut and high degree of recovery.Despite researches and applications in terms of the profile control and water plugging have undertaken against the oil reservoir,the validity period is short with relative ineffective performance.Thus,it is essential to conduct experiment and application research on the Threephase foam technology,against the issues of high water-cut,short validity and poor effect in the oil reservoir development.With the aim of assessing the Three-phase foam system that adapt to the geological features and crude properties of reservoirs in Block A,this project selects the Three-phase foam system through static and dynamic experiments in the first place.Furthermore,it simulates the geological conditions of the block,utilizes this system to undertake displacement experiment,and then optimizes the cost-effective injection capacity and evaluates the injectivity on the basis of the experiments.In the end,the reservoir numerical simulation technologies are applied to create reasonable predictions on the effectiveness of foam flooding.The key of this project is to provide suitable Three-phase foam system for Block A and optimize the injection parameter of the Three-phase foam system;thereby modify water drive channels,effectively reduce watercut in oil well,and consequently achieve high efficient extraction.The optimized Three-phase foam system consists of 0.5% foaming agents,0.3%HPAM,bentonite clay particle with the mass fraction of 0.6% and mesh size of 400.This system can well solve the problem of reservoir heterogeneity in Block A,and it still has relatively high displacement effectiveness in the layer with permeability contrast of 7.According to the research,the injection of 0.3PV three-phase foam enable over 15% reduction of the water-cut.Moreover,it can improve the oil recovery,especially in the low permeability reservoirs;and increase more than 30% of the ultimate oil recovery.Therefore,the proposed Three-phase foam system is able to solve the reservoir heterogeneity and high water-cut issues in Block A,and attain displacement efficiency.