Assessment of Geomechanical Properties along a well in a SAGD Project

• Author / Creator

  Du, Boyang

• Geomechanical properties of caprock shale formations for SAGD operations play a critical role in its integrity and must be well characterized. As a component of the development of a SAGD project, numerical simulations are used extensively to understand the uncertainties and forecast the economics of the project. For caprock integrity related studies, it is extremely important to establish accurate geomechanical properties. One of the primary elements in carrying out a geomechanical and hydraulic analysis is establishing the in-situ stress state. The magnitude and potentially even orientation, of the in-situ stress can limit the maximum operating pressure, prevent surface heave and maintain caprock integrity.
  This research focusses on the development of geomechanical properties and in situ stress estimates from data collected from a well drilled as part of a SAGD project in NE Alberta. Diagnostic formation injection tests or mini-frac tests were conducted at four different depths and pressure transient analysis techniques were used to determine the consistent closure pressure as estimation of the minimum in-situ principal stress. Additional interpretation techniques were adopted to estimate the maximum horizontal stress. In this research, a numerical modeling history match approach was adopted to estimate the maximum horizontal in situ stress. However, determining the magnitude of the maximum horizontal stress remains uncertain for this wellbore location. Geomechanical behavior of the caprock material from the Clearwater Formation and Wabiskaw Member were determined from limited experimental data through a numerical history matching procedure which provided the constitutive parameters for a strain softening model used in the numerical modeling components of this research. The research also integrated geophysical logs such as image log to estimate the stress orientation and calibrated the oriented caliper log to invert for stress magnitude. Integration of all these data types and analysis methods established a consistent stress gradient for this location in comparison to other regional studies and indicates primarily a strike-slip stress state.

• Subjects / Keywords

  • In-situ stress
  • Constitutive Model
  • Wellbore Deformation

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-h5be-dm38

• License

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