The Flow Research of Gas-Oil-Sand Three Phase in Wellbore with Heavy Oil Reservoir

摘要

The pressure calculation in wellbore is one of most important techniques in moderate sand production with unconsolidated sandstone heavy oil reservoir. Because the gas oil ratio is lower generally in heavy oil reservoir than that in normal reservoir, the influences that the gas acts on pressure in wellbore in heavy oil and sand mixture often have been neglected. So, it is a matter that is deserved to care how much the influence that the gas acts on pressure calculation is and whether can be neglected. Through research of phase state in flow process of oil and sand mixture(the gas of heavy oil show up by bubbly flow shape), the gas, oil and sand three phase is divided into gas and liquid two phase flow and oil and sand two phase flow. Using the relationship between pressure and dissolved gas oil ratio, viscosity, oil volume factor, the modified mechanistic model of gas-oil-sand has been created. At same time, based on the above-mentioned model, the pressure loss and carrying capacity of oil also have been calculated. The results show: through the gas rate is low in heavy oil reservoir, the influences that the gas acts on wellbore pressure calculation increase with the decrease of pressure and augment of gas oil ratio. Especially, when the pressure falls to one half of saturated pressure, it will have a large influence on the wellbore.