Wave Speed Measurements of Grosmont Formation Carbonates: Implications for Time-Lapse Seismic Monitoring

• Author / Creator

  Ong, Nam

• The Grosmont Formation is a Devonian-aged carbonate platform complex that is estimated to hold over 64.5 billion m3 (406 billion bbl) of bitumen in place, accounting for a significant portion of Canada’s total hydrocarbon reserves. Despite this, the Grosmont formation has largely been undeveloped as a reservoir due to the high degree of heterogeneity, as well as the economic and environmental risks associated with in-situ heavy oil production. For such operations, thermal processes such as steam-assisted gravity drainage (SAGD) are used to reduce the viscosity of the reservoir fluids, allowing them to flow freely towards producing wells. Time-lapse seismic (4D) methods are key tools used to monitor this process, allowing operators to potentially mitigate these risks associated with producing from such a reservoir. However, the proper interpretation of 4D seismic data requires detailed knowledge of how the physical properties of the reservoir rocks respond to the variety of pressure, temperature, and saturation conditions induced by steam injection. In this contribution, bitumen-saturated carbonates from the Grosmont Formation are characterized through ultrasonic velocity experiments conducted in a range of conditions. P- and S-wave velocities of bitumen-saturated samples decreased significantly with increasing temperature, largely governed by fluid effects. Principal component analysis (PCA) of the wave speed measurements highlighted porosity, temperature, pressure, and grain density as the main factors that contributed to velocity variations within and between samples. Multiple linear regressions applied to the dataset of wave speed measurements establish empirical relations between velocity and the predictor variables determined through PCA. These results provide insight into the behavior of heavy oil saturated rocks under production conditions, however, further measurements at seismic and well-logging frequency ranges are recommended for proper interpretation of seismic data.

• Subjects / Keywords

  • Rock Physics
  • Grosmont
  • SAGD
  • Seismic
  • Bitumen
  • Geophysics
  • Ultrasonic Velocity

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-mhkn-dp05

• License

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