Non-Newtonian flow characterization of heavy crude oil in porous media

Abstract

As a temperature-sensitive non-Newtonian fluid, the seepage of heavy crude oil in porous media shows the non-linear characteristics. The flowing behavior of three heavy oils through porous media is experimentally investigated, and the influence of temperature and pressure-drop on this flowing process is also described. Thereafter, based on the flowing behavior of heavy crude oil, the new models of productivity of the thermal producers (including vertical well and horizontal well) are proposed. In these models, both the threshold pressure gradient (TPG) and thermal effect are taken into account. The flowing experiments of heavy oil in porous media indicate that the pressure gradient and temperature have the significant influence on the flowing process because of the existence of threshold temperature and TPG. Heavy crude oil begins to flow only when the pressure gradient is in excess of TPG, and there dose not actually exist TPG above the threshold temperature. The viscosity-temperature curves demonstrate that the viscosity of heavy crude oil has an obvious feature of two straight-lines on semilog coordinate. On account of the damage of overlapping phenomena of asphaltenes in crude oil, when temperature is higher than the critical temperature, the reducing trend of TPG (with the increase of temperature) will be lessened. Furthermore, on the basis of flowing process of heavy crude oil, the concepts of threshold temperature and certain production temperature of thermal wells are introduced. That heavy oil with a higher viscosity would have a higher threshold temperature, as well as the certain production temperature. The application of horizontal wells tremendously increases the oil recovery rate in comparison with the vertical wells. This investigation could be used as a tool to study the flowing process of heavy oil and productivity calculation of thermal wells in heavy oil reservoirs.

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

“…It increased as permeability decreased for the same heavy oil. Dong et al [23] observed a similar behavior. This was attributed to the fact that the migration of heavy oil was influenced by the properties of fluid and porous media [31].…”

“…Heavy oil starts to flow when the pressure gradient exceeds the TPG and the flow does not follow Darcy's law [22,23]. It is similar to the Bingham fluid because it does not express a shear rate until a specific stress (i.e., yield stress) is imposed.…”

“…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].…”

Immiscible Displacement of Viscoplastic Waxy Crude Oils: A Numerical Study

“…The most striking non-Newtonian feature of waxy crude oils is their viscoplastic behavior. This means that these oils do not flow unless a certain stress thresholdthe so-called yield stressis exceeded (Wardhaugh et al, 1988;Chang et al, 1999;Davidson et al, 2004;Dong et al, 2013). The existence of yield stress makes a theoretical study of the water-flooding operation much more difficult for such fluids.…”

Toward an optimal design principle in symmetric and asymmetric tree flow networks

“…However, there is the recognition that body fluids (e.g., blood) and fluids used in industrial applications often exhibit non-Newtonian (non-linear) behavior (Schreiner et al, 1997;Chhabra and Richardson, 1999;Baieth, 2008;Dong et al, 2013). Non-Newtonian rheology has a significant impact on flows in narrow-diameter tubes.…”