Regional Stress Variations in the Pembina-Warburg Area of the Alberta Basin: Implications in Coalbed Methane Exploration

Abstract

This study documents a comprehensive investigation of the in-situ stress magnitude and orientation data from borehole breakouts, mini- and micro-fracture tests, bulk density logs and other stress data, for strata in or adjacent to the Mannville Group and Edmonton Group coals in a part of the west-central Alberta Basin, Canada. The horizontal in-situ stress orientation data can be used to plan horizontal well trajectories in the coal strata of interest to intersect natural fractures and cleats possessing the highest permeability. Horizontal stress orientation data can also be used to assess the effects of well trajectory or borehole collapse risks during drilling, completions, and production operations. Subtle variations in the vertical total stress in the study area may reflect similar trends in the mean effective stress. However, this would need to be confirmed with more complete horizontal stress magnitude and formation pressure data.

Keywords:

• coalbed methane
• Alberta Basin
• Mannville/Edmonton Groups
• stress variation