Flow Characteristics of Heavy Oil through Porous Media

Abstract

Performance of flowing through a capillary and porous media for different kinds of heavy oil at different temperatures have been studied by experiments in this article. It shows that the heavy oil containing asphaltene-colloids displays yield-stress rheology (Bingham fluids). The displacing pressure difference increases linearly with the increase of the flow rate. However, the start flowing pressure is different for different heavy oil samples at different temperatures. The higher the temperature is, the lower pressure the heavy oil needs to flow; and when the temperature is high enough, the start flowing pressure equals zero. The minimum temperature at which the start flowing pressure equals zero is called converting temperature. Also, the more viscous the heavy oil is, the higher the converting temperature will be. An exponential relationship of yield stress and temperatures has been obtained for different kinds of heavy oils by the experiments of heavy oil flowing through a capillary. A logarithmic relationship of converting temperatures and the dead oil mobility at 50°C has been obtained for heavy oil through different porous media. When a temperature is lower than the converting temperature, the start flowing pressure gradient decreases as a log tendency with the increase of temperature when different heavy oils are flowing through different porous media. For the existence of the start flowing pressure gradient, the heavy oil production rate is different from that for the Newton fluid and it is adverse to the development of heavy oil reservoirs. The test results are favorable to choose the reasonable temperature for heavy oil transportation running in a pipe or well bore and also determine the temperature limitation for different production rates for a specific well sample. It is also important for improving the development effect efficiently.