Wellbore Flow Pattern Research In Gas Well Of Producted Heavy Oil

On the basis of the composition and viscosity-temperature characteristics analysis of heavy oil,11 kinds of viscosity reducer are selected from the commonly used of water-based and oil-based viscosity reducer,and they are mixed five different concentration of the sample with the heavy oil,under the conditions of wellhead temperature 9 ℃ and bottom hole temperature 34 ℃,to adopt RS-6000 rheometer tested the rheology of these sample,Rheological parameters and apparent viscosity of heavy oil are given respectively.The results showing:under the condition of low dosage,water-based viscosity reducer can increase the viscosity of heavy oil,so cannot be used in ALX gas Well;oil-based viscosity agent can effectively reduce the viscosity of heavy oil,Considering from two aspects of technical indexes and economic costs,Optimizing the CY1 JL viscosity agent,and the best dosage range of 22%~25%.According to the condition which the wind blow the surface of the water to make Jeffreys H.waves,referring the gas-liquid two phase flow pattern criterion and flow pattern distribution map of Taitel Y.-Dukler A.E.in level pipe,adopting extreme value method to determine the speed which the waves speaded to the downstream and choosing average Jeffreys cover coefficient,established the maximum viscosity equationsof heavy oil which airflow can carry heavy oil in the loop-fog flow state,according to the actual production data,calculated the highest viscosity of heavy oil which airflow can carry out heavy oil(target value of gas well heavy oil viscosity reduction) is0.02092914 mPa.s in ALX gas well.According to the method of Turner,from the Angle of improve gas well production and optimizing production string,a large amount of calculation is done. The calculation results show:If you want to produc heavy oil in gas well,the gas production should be increased to nearly 2.4×104m3/d,it is greater than the actual production in gas well; If you want to the lift the largest droplet to the ground, the production string diameter must be reduced from 62 mm to 30 mm.In the level,if the liquid film can be stripped in the form of a droplet from the pipe wall,and lifted with the air flow rates together,air velocity must overcome the surface tension and viscous elastic modulus of the liquid film of heavy oil,combined with Jeffreys puted forward the equation of producing wave,setting up the correcting Jeffreys equation.According to the calculation results of the correcting Jeffreys equation show:when the surface tension and viscous elastic modulus are considered at the same time,the wellbore is fully occupied by heavy oil liquid membrane,gas well is fully blocked,there is no production.In the vertical,according to the method of Ansari,if liquid membrane can flow upward along the wellbore wall,pressure gradient of gas core and pressure gradient of liquid film is equal. According to the calculation results show:when the liquid film thickness of heavy oil is more than 3mm(in addition to the liquid film thickness is equal to 15 mm),liquid film may flow upward along the wellbore wall,heavy oil can be producted to the ground.