Fold-related fractured reservoir analysis of the Pennsylvanian Ksituan Member of the Belloy Formation, Monkman Pass, northeastern British Columbia: Optimal drilling directions determined from image log and outcrop studies.

摘要

The Ksituan Member of the Pennsylvanian-Permian Belloy Formation contains three main lithofacies: dolomudstones, dolowackestones and dolopackstones. Out of the three studied, the dolowackestones have the best reservoir quality due to the interaction of fractures and matrix porosity, followed by the dolomudstone and dolopackstone lithofacies.; Six main fracture orientations are observed at all fold positions in outcrop and subsurface data. The two dominant fracture orientations are orthogonal and directly related to in situ principal stresses that are slightly oblique to the structural trend of the area. The second most dominant sets consist of Stearns' regional Type 1 and fold-related Type 2 fractures. The remaining two sets have been interpreted as fractures related to a paleo-stress regime, perhaps basement normal faulting.; An optimal drilling direction can be determined through the use of occurrence and should target the crest of the structure at an orientation perpendicular to the regional compressive stress direction.