Abstract

Elastic and plastic mechanical properties of liquids-rich shale rocks play a critical role in well placement and stimulation. In this study, elastic, plastic, and failure behavior of the Lower Jurassic Nordegg Member from various wells in the Western Canada Sedimentary Basin is investigated with laboratory triaxial compression tests. The triaxial compression tests show a wide range of elastic parameters, e.g. Young’s moduli ranging from <10 GPa to >30 GPa and Poisson’s ratios from <0.15 to >0.35. Mechanical anisotropy is also observed with vertically-oriented samples (normal to bedding) generally having lower compressive strength and Young’s modulus than horizontally-oriented samples (parallel to bedding). The characteristics of plastic deformation, brittle and/or ductile behavior, and residual strengths are also investigated. The variability in measured mechanical properties suggests the highly variable lithologies and fabrics in these samples. Efforts are made to delineate possible correlations between the rock mechanical properties, mineralogy, fabric, porosity, and pore-throat size distribution. The study also discusses the implications of the variable elastic and plastic mechanical properties on determining optimal placement of horizontal wells in the Nordegg Member, designing for multistage-fracture stimulation and selecting appropriate proppant. Proppant embedment and fracture conductivity are discussed using laboratory data and analytical and numerical analyses.

This content is only available via PDF.
You can access this article if you purchase or spend a download.