Research On Numerical Simulation Application Of Heavy Oil Chemical Viscosity Reduction Combined Flooding

This block is a heavy oil reservoir with high porosity and permeability.Analysis of the dynamic development parameters and well production data of the reservoir after it was put into production in 2003 found that the formation energy loss was serious,and many wells are forced to shut down due to low productivity and high water cut.The viscosity of formation crude oil is high,some oil wells cannot produce fluid,and other oil wells have high water production.Different well groups have obvious differences in effectiveness,so reservoir production is low.Aiming at the problem of poor effect of conventional development methods for high porosity and high permeability heavy oil reservoirs,based on numerical simulation technology,a poly-surface binary compound chemical flooding method is proposed.Firstly,based on the core displacement experiment fitting,this paper designs the orthogonal test,using the method of range analysis to study the parameters affecting the composite system and conduct sensitivity analysis of five parameters.Secondly,based on the actual data of the mine,a three-dimensional geological model is constructed to fit the production process of the block from June 2010 to June 2017,and classify the block in the remaining oil enrichment area.Finally,the optimization scheme of injection production parameters of chemical flooding is designed,and the water flooding is used as the control group.The development effect of the scheme is predicted and analyzed.The combination of injection programs in the research block will be of guiding significance for the adjustment of the mid-to-late stage of heavy oil reservoir development.The research results show that using the cumulative oil production as the evaluation index,the sensitivity order of the parameters is as follows:viscosity reducer concentration,adsorption,inaccessible pore volume,residual resistance coefficient,injection viscosity.When the concentration of viscosity reducer reaches the critical micelle concentration,the structure of surfactant molecules will change from single molecule to micelles,which will make the viscosity reduction effect worse.The adsorption affects the effective time of the production well.The greater the amount of adsorption,the later the effective time of the oil well.The larger inaccessible pore volume,the earlier the effective time.The increase of the residual resistance coefficient can enlarge the sweep area.The larger the polymer injection viscosity,the more remaining oil can be used,but the cost should also be considered.On the basis that the block satisfies the history matching,experiments and groups are divided to optimize the parameters of polymer surface binary composite chemical flooding in heavy oil reservoir.The optimized polymer injection concentration is 1600 mg·L^-1 and the injection rate is 130 m³·d^-1,the injection volume is 0.35 PV,the viscosity reducer injection concentration is 0.05%,and the poly-surface slug ratio is 3:2.Four different injection schemes are designed.Under the condition of the above injection conditions unchanged,the injection of the chemical agent alternates twice is the best.Recovery factor can be increased by 17.8%,and the final recovery factor is 42.1%.