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 ı 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.

Non-Newtonian Flow Characteristics of Heavy Oil in the Bohai Bay Oilfield: Experimental and Simulation Studies

“…The viscosity of oil sample #5 was 586.8 mPa•s, which was double than that of oil sample #6 at 30 °C. This is due to the interaction force between various molecules because they increase as the asphaltene content rises, resulting in an easier asphaltene aggregation and a stronger network structure [7,8,19,64].…”

“…Resins can develop a steric layer around asphaltenes to prevent them from overlapping, but the impact is lower than that observed from asphaltenes on viscosity [17]. (3) The rheology of heavy oil exhibits a Bingham behavior, which has been demonstrated in several studies [18][19][20][21]. Most of these previous studies focused only on one or two aspects and thus, this work cannot be considered as being comprehensive.…”

“…The TPG is one of the key parameters of the Bingham fluid found in heavy oil reservoirs [19]. It has a significant influence on oil productivity and recovery in addition to affecting the determination of reasonable well spacing and the distribution of remaining oil [26].…”

“…The steady-state method is most commonly employed as the test method of flow characteristics over the other methods due to its great advantages of test system stability, high precision and reliable data [23,[34][35][36]. The single-phase flow of heavy oil has been studied by the steady-state method [9,19,23]. Heavy oil does not flow until the displacing pressure gradient reaches the TPG.…”

“…Heavy oil does not flow until the displacing pressure gradient reaches the TPG. When the displacing pressure gradient is higher than the TPG, the flow rate of heavy oil increases linearly [19]. The flow behavior of heavy oil does not follow Darcy's law as it belongs to non-Newtonian flow [31,37,38].…”