Experimental and Numerical Modeling of the Thermal Conductivity of High-Viscosity Hydrocarbon Systems

Musin

2016

Braz. J. Chem. Eng.

-The results of two-dimensional mathematical modeling of heat and mass transfer in a highly viscous hydrocarbon liquid by inductive and radio-frequency (RF) electromagnetic (EM) heating are presented. The model takes into account the dependence of the liquid's viscosity and thermal conductivity on the temperature and also the presence of thermal convection effects. It is shown that the occurrence of volumetric heat sources inside the liquid caused by EM radiation yields an intensive deep heating as compared with inductive heating. Numerical calculations show that, in both these cases, the single vortex flow structure is formed in the whole volume of the liquid. However, RF EM heating provides a more homogeneous distribution of heat in the medium and requires three-fold less power consumption in comparison with induction heating.

Section: Additional Relationsmentioning

confidence: 99%

“…The dependence of the conductivity coefficient of the liquid on the temperature was set as linear (Kovaleva et al, 2005):…”

Section: Additional Relationsmentioning

confidence: 99%

“…-induction (contact) heating is modeled by placing the distributed sources of heat on the inner tube of the reservoir (2 in Figure 1) (Kovaleva et al, 2005):…”

Section: Additional Relationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Numerical Modeling of Heavy Hydrocarbon Liquid Heating

Musin

2016

Braz. J. Chem. Eng.

“…Results of experimental research of heating of heavy hydrocarbon systems by an inductive heater and results of mathematical modeling of this experiment were reported in [1]. The thermal convection of the fluid was taken into account by introducing an effective thermal conductivity.…”

Section: Introductionmentioning

confidence: 99%

Modeling of heat and mass transfer in a hydrocarbon fluid under inductive heating

Kireev

Musin

2009

J Appl Mech Tech Phy

Self Cite

Results of numerical simulations of the thermal action on a high-viscosity hydrocarbon fluid with temperature-dependent viscosity and thermal conductivity are presented. A system of equations of thermal convection in the Boussinesq approximation is used as the constitutive equations to describe the convection of the hydrocarbon fluid. The dynamics of the temperature field and convective structures in the fluid is studied. The spatial motion of the fluid is found to be locally nonuniform; the motion is accompanied by vortex flows; as a result, two regions with significantly different temperatures are formed in the medium. Introduction.Results of experimental research of heating of heavy hydrocarbon systems by an inductive heater and results of mathematical modeling of this experiment were reported in [1]. The thermal convection of the fluid was taken into account by introducing an effective thermal conductivity. The fluid under study was a heavy hydrocarbon system, which has extremely low values of fluidity and thermal conductivity at low temperatures. Based on results of experimental and numerical studies, a conclusion was drawn that the effective thermal conductivity became substantially increased with increasing temperature, which was a consequence of the emergence of local spots of vortex motion of the fluid in regions where the temperature exceeded some threshold value corresponding to the beginning of fluidity. The spatial region where this motion occurred and the temperature field in this region displayed permanent irregular changes, which was observed visually and was recorded by temperature gauges located inside the reservoir. A mathematical model of heating of a heavy hydrocarbon system in a closed reservoir is proposed in the paper to describe the effects noted above. The model takes into account not only the effect of temperature on viscosity and thermal conductivity of the fluid, but also the presence of free convective motion of the fluid.Mathematical Model. We consider a closed metallic reservoir whose base is covered by a concrete layer, and there is an inductor tube in the center. The space between the inductor tube and the outer wall of the reservoir is filled by a high-viscosity hydrocarbon fluid. Some part of the inductor tube wall is heated by the inductor tube; as a result, the fluid becomes heated. The computational domain corresponding to the physical model described above is schematically shown in Fig. 1. The problem is solved in an axisymmetric formulation in a cylindrical coordinate system with the origin in the center of the reservoir base and with the z axis directed upward, perpendicular to the base. From the viewpoint of mathematical modeling, the physical model is a multilayer system consisting of the inductor tube, concrete layer, and hydrocarbon medium (see Fig. 1). The temperature field is calculated in each layer; the velocity field of the convective flow of the fluid is additionally determined in the hydrocarbon medium.

Numerical Modeling of Heavy-Oil Recovery Using Electromagnetic Radiation/Hydraulic Fracturing Considering Thermal Expansion Effect

Davletbaev

Journal of Heat Transfer

Зайнулин

et al. 2018

Production of heavy oil from deep/tight formation using traditional technologies (“cold” production, injection of hot steam, etc.) is ineffective or inapplicable. An alternative is electromagnetic (EM) heating after fracturing. This paper presents the results of a numerical study of heavy oil production from a well with hydraulic fracture under radiofrequency (RF) EM radiation. Two parameters ignored in our previous modeling studies, namely adiabatic effect and the thermal expansion of oil, are considered in the new formulation, while high gradients of pressure/temperature and high temperature occur around the well. The mathematical model calculates the distribution of pressure and temperature in the system of “well-fracture-formation.” The distribution of thermal heat source is given by the Abernetty expression. The mathematical model takes into account the adiabatic effect and the thermal expansion of heavy oil. The latter makes a significant contribution to heavy oil production. Multistage heavy production technology with heating is assumed and several stages are recognized: stage 1: “Cold” heavy oil production, stage 2: RF-EM heating, and stage 3: RF is turned off and “hot” oil production continues until the flow rate reaches its initial (before heating) value. These stages are repeated starting from the second stage. Finally, RF-EM heating technology is compared to “cold” production in terms of additional oil production and economics. When producing with RF-EM heating with power 60 kW (50 days in the second stages), the oil rate increased several times. Repeated RF-EM heating (25 days in the fourth stage) doubled the production rate. Near-well region temperature increased by ∼82 °C in the second stage with RF-EM heating. Temperature increased by ∼87 °C in the fourth stage with repeated RF-EM heating and production cycles. Economic analysis and evaluation of energy balance showed that the multistage production technology is more efficient; i.e., the lower the payback period, the greater the energy balance. With the increase in pressure difference, the payback period and energy balance increased linearly.