Study On Influence Of Hydraulic Pulse Jet On Microe Mulsification And Percolation In Heavy Oil Thermochemical Flooding

China is rich in heavy oil resources,and thermal and chemical viscosity reduction is a key stimulation technology for improving the efficient development of heavy oil reservoirs.Heavy oil thermal chemical flooding technology that combines the advantages of both can further improve the viscosity reduction effect and crude oil recovery.However,promoting effective contact between viscosity reducer and heavy oil is a prerequisite for improving the application effect of this composite viscosity reduction technology.Due to the effect of hydraulic pulse jet on stimulating fluid solid interaction,it has the potential advantages of reducing near-wellbore seepage resistance in heavy oil reservoirs,improving oil water agent flow patterns,and increasing crude oil recovery as a composite innovative technical means for thermochemical flooding of heavy oil.Based on the composite displacement scheme of post hydraulic pulse jet assisted pre heavy oil thermochemical displacement and the research method of multiple experimental equivalence/correlation,experiments on the influence of hydraulic pulse jet on heavy oil thermochemical displacement,as well as equivalent microscopic visualization experiments and numerical simulation studies,were conducted.First,by recording the changes of macro phenomena at the injection production end,the phased changes of recovery rate,injection production pressure difference and oil-water relative permeability are analyzed,and the production increase effect of the combined flooding scheme is preliminarily clarified;By analyzing the micro oil water emulsification state and seepage law in the observation area,further reveal the macro micro seepage principle of the composite displacement scheme;Finally,by establishing mathematical and physical models to analyze the changes in seepage flow in the calculation area under the composite flooding scheme,the influence mechanism of hydraulic pulse jet with different intensities/frequencies on pre thermal chemical flooding of heavy oil was systematically revealed.The results indicate that the effect of periodic hydraulic pulse jet on the pre heavy oil thermochemical displacement has a phased characteristic.As the intensity of hydraulic pulse jet increases,the displacement effect changes more significantly,and the effect of higher intensity hydraulic pulse jet is mainly manifested in two aspects:(1)promoting full contact between oil water agent solid,improving the oil washing efficiency of viscosity reducing agent solution,and facilitating the formation of W/O type emulsion,And the weighted average particle size of dispersed phases in the three stages reached 29.05μm、48.29μm、29.38μm.(2)Promote the pre displacement fluid to further affect the oil phase in the pore throat,accelerate the dynamic response of the leading edge thermochemical agent solution to hydraulic pulse jet waves.In indoor displacement experiments and numerical simulation experiments,the final recovery rate increased by 6.16% and 14.31% compared to the respective control groups,respectively.Under the premise of optimizing the intensity,the medium frequency hydraulic pulse jet can further enhance the development effect of the composite displacement scheme.In indoor displacement experiments and numerical simulation experiments,the final recovery degree is as high as 31.59% and 16.35%,respectively.The study aims to provide theoretical guidance for the design of new composite development schemes for heavy oil reservoirs by revealing the stimulation mechanism of a new type of heavy oil composite development process with physical chemical synergistic effects.