Influence Of Rheological Properties And Wetting Behavior Of Produced Fluid In Asp Flooding On Eccentric Wear Of Sucker Rod Tubing

The ASP flooding oil recovery technology has entered the late stage,the water content in the produced fluid has increased significantly,and the emulsion has been converted from a W/O type emulsion to an O/W type emulsion.The factors affecting the viscosity of oil-water emulsions are complex,and the particle size distribution range of the dispersed phase,the properties of the interfacial film,the viscosity of the dispersed phase and the volume fraction of the dispersed phase are the main factors affecting the viscosity of the emulsion.With the gradual transition of oil wells to aging wells,the phenomenon of eccentric wear and deformation of sucker rods during oil production is relatively serious,which seriously affects the production concept of efficient and low-consumption development of oilfields,and also causes oilfield production costs to rise and benefits to change.However,compared with water flooding and polymer flooding,the eccentric wear phenomenon of oil wells in ASP flooding has slowed down.Through on-site investigation,it is found that in ASP flooding oil wells with high surfactant concentration,the number of pump inspections of oil wells is higher than that of oil wells.There are few other oil wells.Therefore,it is very important to study the rheological properties and wetting properties of the ASP flooding emulsion to reduce the eccentric wear of the sucker rod.This paper uses theoretical analysis to find that the viscosity and shear rate of the dispersed phase and the oil phase are the main factors affecting the rheological properties of the ASP flooding emulsion.The solubility of polymers,surfactants and alkalis in pure oil is poor.Therefore,the three have little effect on the viscosity of the oil phase;the macroscopic characterization of the emulsion under different component concentrations was observed by an optical microscope,and the normal distribution of the particle size of the emulsion under different component concentrations was obtained.With the increase of alkali and surfactant components,the particle size of the emulsion gradually decreases,and the minimum is 7um.In this paper,the DSA(drop sharp analysis)experiment was used to measure the wetting angle of the emulsion droplets under the wellbore slice under different component concentrations,and a two-dimensional numerical calculation model of the wetting angle under different roughness was established.The results found:With the increase of water content and polymer concentration,the wetting angle increases;with the increase of alkali and surfactant components,the wetting angle decreases,and the better the adsorption of droplets,the stronger the wettability.In this paper,a two-dimensional calculation model of the friction force of the wellbore slice is established by numerical simulation,and the shear stress and deformation of the contact center of the friction pair are analyzed.The performance was analyzed,and it was found that the stress distribution at the contact center of the friction pair showed a"butterfly shape".The smaller the value,the smaller the stress value,the larger the surfactant,the better the lubricity of the emulsion.In this paper,the fluid-solid coupling calculation model combined with UDF(User Defined Function)method is used to analyze the displacement,stress and deformation of the sucker rod pipe in the ASP flooding wellbore due to fluid flow.It was found that the position of the pipe and the speed will form a vortex,which will lead to the secondary displacement of the rod pipe,the maximum secondary displacement can reach 1.162?10^-7m/s;the micro-deformation of the sucker rod pipe can increase to 9.639?10^-7m,the maximum pressure of the pipe occupies the largest area at the interface,and the length can reach 0.32m.