Wellbore Lift Technology Optimization Based On Viscosity Characteristics Analysis Of Water-containing Heavy Oil

The heavy oil reservoirs in the Xianhe are mainly composed of super heavy oil and extra heavy oil,which has strong temperature sensitivity.As the water cut and temperature of heavy oil wells vary greatly in different production stages,the viscosity of crude oil also changes greatly,thus affecting the production load and energy consumption of pumping units because the load of pumping units increases greatly with the viscosity of crude oil.Therefore,in order to analyze the problem of heavy crude oil wellbore lifting,it is necessary to carry out dynamic analysis on the viscosity of oil-water mixture under different components,different water cuts and temperatures of heavy oil.In this paper,heavy oil wells of different blocks and different viscosities in Xianhe area are selected to carry out emulsified viscosity test of heavy oil,which under different temperature and water cut conditions.By means of grey entropy correlation analysis of four components of heavy oil polarity and the method of scanning electron microscope observation,the internal and external causes affecting the viscosity of heavy oil and the changing rules are clarified,and the inflexion point formula of heavy oil inverse emulsification is deduced.Considering of the actual wellbore conditions and other heavy oil assistant thermal recovery technologies,the boundary conditions(temperature,water cut)for controlling viscosity during wellbore lifting in different heavy oil wells are determined,and the wellbore lifting technology charts for different emulsified heavy oil are worked out to guide the wellbore lifting technology.At present,heating by using electric is efficient to reduce the viscosity of the heavy oil.viscosity reduction by wellbore electric heating is the leading technology for solving lifting problems in heavy oil production.In this years,with the development of some super heavy oil and super heavy oil reservoirs,the number of wellbore electric heating wells has been increasing year by year,the power consumption is increasing day by day,and the operation cost remains high.Using the wellbore lifting technology chart,the operation mode of electric heating for heavy oil in different units can be optimized.And the number of the wells with electric heating are controlled.According to the statistics,73 wells with electric heating in Xianhe oilfield were reduced,which accounts for 38.45% of all the electric heating wells.The annual average energy consumption was saved by 8.76 million kilowatt hours,and the economic benefit was remarkable.