Pressure and temperature dependence of acoustic wave speeds in bitumen-saturated carbonates: Implications for seismic monitoring of the Grosmont Formation

Abstract

Recent time-lapse seismic observations in carbonate reservoirs subject to steam-assisted enhanced oil recovery display substantial changes in seismic reflectivity due to the combined effects of saturation, pressure, and temperature. Understanding these field seismic observations requires knowledge of the effects on the seismic wave speeds in bitumen-saturated carbonates. We have conducted ultrasonic measurements of P- and S-wave velocities in bitumen-saturated dolomite taken from the Grosmont Formation in northern Alberta. Wave speeds are measured under a variety of conditions of constant pore pressure, constant effective pressure, and with varying temperature to map the various controlling factors. The temperature-dependent declines of 12% and 9% for the P- and S-wave speeds, respectively, with temperatures from 10°C to 102°C are most notable. Unlike oil sands, at times, the dolomite retains its structure upon removal of the bitumen allowing for measurement of the dry and water-saturated frame properties and their subsequent use in substitutional modeling. None of the standard bounding, inclusion, or Biot-Gassmann family models adequately describe the observations in the heated sample. The deviations may be in part due to the inability of these models to properly incorporate the complex bitumen non-Newtonian rheology including a bulk viscosity.

Temperature Effect on the Velocity‐Porosity Relationship in Rocks

“…The results in Figure 13 are similar to the trend of the attenuation in heavy oil saturated carbonates obtained by Rabbani et al. (2017). This may be due to the fact that attenuation is affected by the viscosity of the fluid (Vasheghani et al., 2009).…”

“…The porosity was measured by the gas‐expansion method (Stevens, 1939) under room temperature and atmospheric pressure. The permeability was measured with a gas permeameter (Rabbani et al., 2017).…”

“…Several studies about the effect of temperature on the attenuation and dispersion characteristics of seismic waves in complex reservoirs have been carried out (Jaya et al., 2010; Rabbani et al., 2017; Xi et al., 2007; Zhu & Pan, 1993). These studies offer some insights to understand the link between temperature and wave attenuation in rocks.…”

A Seismic‐Frequency Laboratory Study of Solid Substitution in Bentheim Sandstone

“…The laboratory studies of solid‐filled rocks presented in literature are rather numerous (see, e.g., Batzle et al, ; Behura et al, ; Chopra et al, ; Han et al, ; Kato et al, ; Spencer, ; Sun & Han, ; and Rabbani et al, ) but are mainly limited to experiments at ultrasonic frequencies. One main implication of a number of experimental investigations (Batzle et al, ; Behura et al, ; Das & Batzle, ; Hinkle et al, ) is that the elastic parameters of heavy oil in a quasi‐solid state are strongly frequency‐dependent.…”

Rock-physics characterization of bitumen carbonates: A case study

“…Different from bitumen sands, bitumen carbonates are generally stiffer rocks with smaller porosity and lower permeability. Rabbani et al (2014Rabbani et al ( , 2017 measure the bitumen-saturated Grosmont carbonates under different pressure and temperature conditions and try to simulate the carbonate samples with geometric models. Chen et al (2015) extend Rabbani's measurements to a broader pressure range.…”