Design Of A Water-bearing Heavy Oil Blending Mixer In Tahe Oilfield

Down-hole heavy oil blending is an important technology for heavy oil recovery.Thin oil is injected from the annulus and mixed with heavy oil in the pipe to achieve the purpose of viscosity reduction.However,due to the low flow rate of heavy oil,the mixture cannot be fully mixed depending on the flow of thin oil and heavy oil itself,thus the viscosity reduction is not much effective.The heavy oil blending and mixing tool is widely used by changing the direction and flow velocity,increasing the contact area of heavy oil and thin oil so as to improve the mixing effect.When it is applied to heavy oil with high water cut,the down-hole blending mixer ignores the influence of the oil-water two-phase flow pattern on the mixing viscosity reduction,which makes the mixed liquid viscosity reduction effect worse.Therefore,this paper conduct in-depth research on the mixed-mixing tools for water-bearing heavy oil wells,combined with numerical simulation and physical simulation.The paper mainly carried out the following works:(1)This paper statistically analyzes the water cut of the production Wells,tests the viscosity-temperature characteristics of the heavy oil and the thin oil in Tahe oilfield,evaluates the viscosity-reducing effect of the thin oil used in the field on the heavy oil,and optimizes the calculation model of the viscosity of the heavy oil with the thin oil,which provides the basis for the development of a new type of underground mixing tank(2)The physical model of siphon mixer used is established,and the optimal calculation model of heavy oil blending with dilute viscosity is introduced by UDF,the mixing effect of siphon mixer is simulated numerically,and the influence rule of water content on viscosity reduction effect is analyzed,which provides research ideas for designing new underground siphon mixer in Tahe oilfield.(3)Based on the flow pattern of oil-water two-phase upward pipe flow,a water-rich heavy oil blending mixer was designed,and the Fluent numerical model was established to analyze the effect of oil-water swirling separation and jet mixing,and the number of pipes in the jet mixing section was optimized based on the ratio of oil to water.(4)The visualized physical simulation experiment was carried out for the mixing device of water-bearing heavy oil to analyze the mixing effect of different liquid amounts and water contents:with the increase of flow rate,the effect of water removal was enhanced and the mixing effect was improved.In this paper,considering the influence of water cut on the mixing effect of mixed mixture,a down-hole mixing mixer suitable for the heavy oil is designed,which is of guiding significance for the underground thickening process of water-bearing heavy oil well in Tahe Oilfield.