Calculation And Analysis Of Wellbore Temperature Distribution In The Super Heavy Oilfield

The temperature change in a wellbore affects oil production directly, during the production of oil well, especially the super-heavy oil production. A model to calculate the distribution of temperature, pressure and steam quality in the wellbore during the production of super heavy oil steam-injection is developed by analyzing the related domestic and overseas researches on the basis of the theory of vertical multiphase flow and the law of energy conservation. Considering the correlativity among the pressure, temperature and steam quality synthetically, the four ranks Runge-Kutta method is used to calculate the steam parameters in this paper. A mathematical model is developed to calculate the temperature distribution in the wellbore considering the asymmetry of the well fluids in super heavy oil well when electric heating rod is used to produce heavy oil. The Fully Implicit Method is used to solve this model based on the consideration that the character such as the viscosity, density and coefficient of heat conductivity of extra heavy oil are sensitive to the unknown temperature. The relevant software for calculating is made using VB language based on the mathematic model by which the temperature distribution of the fluid in the wellbore is calculated in different situations such as heating power, oil rate, water cut and formation temperature. The result is satisfactory when compared with practical data of the oilfields, and it is advisable to use this model in practice. The sensibilities of the numerable factors which can affect the temperature in and around the wellbore are analyzed using the software in this paper. Theory and means are supplied according to research on particular super thick oil well pit shaft temperature distribution calculation and analysis. This research will play a significant role in guiding the technology parameters design of that type oil well's steam injection and oil production.