Viscosity of Alaska Heavy Oil Saturated with Methane

Abstract

Viscosity, μ, of Ugnu heavy oil (North Slope of Alaska, USA) saturated with methane was measured at temperatures from 0 to 60 °C, pressure from 15 to 1800 psi, and shear rate of 0.1−500 s −1 using a high-pressure rheology apparatus constructed for this work. Under all saturated conditions, the oil behaves as a Newtonian fluid. The influence of temperature, pressure, and methane concentration was analyzed, and important regularities in the viscosity were established. A two-variable Antoine-type correlation, μ = f(T, p), with 6 fitting parameters was developed using 48 points on a p,T,μ-diagram for Ugnu oil. Since produced oil is accompanied by sand and water, their influence on the viscosity of Ugnu oil saturated with methane at 1500 psi was also studied. The relative viscosity of the Ugnu oil + water emulsions at temperatures from 2 to 60 °C increased linearly with increasing water concentration from 0 to 20 wt % following the Einstein viscosity model for dilute suspensions. Although possible in the time scale of days, hydrate formation at temperatures below 13 °C (thermodynamic hydrate formation temperature at 1500 psi) did not interfere with the rheological measurements for the emulsions. Due to rapid sand particle sedimentation in methane-saturated Ugnu oil during experimental stages, the impact of sand concentration on the live oil viscosity could not be evaluated. Overall, the viscosity of Ugnu oil as a function of pressure and temperature can be used to simulate the oil's behavior during production.

Rheological and Chemical Properties of Alaska Heavy Oils

“…The average enthalpy of solution of methane in the Ugnu oil was estimated to be -2.0 ± 0.3 kJ•mol -1 , which is in agreement with literature data [12]. More details about the developed p,T-correlation can be found elsewhere [8].…”

“…For high-pressure measurements, a unique high-pressure rheology setup rated for pressures from ambient to 2000 psi and temperatures from -10 o C to 150 o C was constructed. A schematic of the high-pressure setup is shown in Figure 2 and detailed in three very recent publications [6][7][8]. The design uses a high-pressure Couette system with a magnetically driven concentric cylinders geometry (1 mm gap), a stand-alone high-pressure vessel for mixing/saturation, and a high-pressure syringe pump connecting the two vessels.…”

“…Consistency coefficient K as a function of sand and water contents at 20°C for MPS-37 Contour of shear thinning degree m as a function of sand and water contents at 20°C for MPS-37Figure 10. p,T-dependence of methane saturated Ugnu oil: black lines, isotherms; grey lines, isopleths (constant liquid concentration), adapted from[8] 7 URTeC 1619821…”

“…Temperature dependence of relative viscosity of "live" Ugnu oil + water emulsions at different mass fractions of water at pressure pref =1520 psi, adapted from[8] Temperature dependence of viscosity of Ugnu oil with isopleths shifted by ∆Tshift (dependent on saturation pressure and determined from the p,T-correlation) along T-axis, adapted from[8] URTeC 1619821…”

Applications of nanotechnology in oil and gas industry: Progress and perspective

“…[63] Nanotechnology provides unprecedented opportunities to promote high efficiency recovery techniques for heavy oil production. Nanoparticles, such as metal oxides, can be used as catalysts in heavy oil in situ upgrading, offering the potential to enhance heavy oil recovery and reduce ground transportation and refining costs.…”