|Title||Résistance mécanique et pressions de fracturation de quelques matériaux rocheux sédimentaires typiques|
|Alt Series||Earth Sciences Sector, Contribution Series 20140370|
|Subjects||fossil fuels; structural geology; sedimentology; fracturing; fractures; hydraulic fracturing; deformation; sedimentary rocks; rock pressures; shales; gas; porosity; permeability|
|Illustrations||photographs; core logs; tables; graphs; formulae|
|Program||Shale Gas - groundwater, Environmental
Compression and micro-fracking hydraulic tests were carried out at the CanmetMINING Rock Mechanics Laboratory in Ottawa, Ontario, to determine the mechanical strength, elastic
deformation moduli and fracking pressures of some typical sedimentary rocks. These tests were initiated, first, to characterize the materials under investigation, and second, to support the assessment of eventual projects either in relation with
shale gas extraction and/or CO2 sequestration, with storage or disposal of natural or used fuels, of radioactive type or not, within these rocks. Test results were excellent, either considering their consistency or their relative dispersion around
the mean. Variations observed can be explained mainly by the modes of deposition (formation) and/or retrieval of these rocks. Micro-fracking tests allowed the verification in laboratory of theoretical models currently used to predict hydraulic
pressures for fracking and circulating fluids through rocks, either intact or fractured, with low porosity and/or permeability.
|Summary||(Plain Language Summary, not published)|
Shale gas is becoming an increasingly important source of natural gas in North America. The gas is tightly locked in very small spaces within the rock,
requiring advanced technologies to stimulate (fracture) the gas-bearing zones. Sedimentary rocks were studied as attention is focussed on their possible use as gas extraction and/or sequestration formations and/or long-term nuclear waste
repositories. Laboratory compression and hydraulic micro-fracking tests were performed at the CanmetMINING Rock Mechanics Laboratory, Ottawa, Ontario, Rock samples from Québec shales (Utica and Lorraine shales) and from an Ontario limestone (Coburg
Formation) were used. Results show great homogeneity and a good concordance with current theories on hydraulic fracking and fracture opening in intact and fractured rocks. This means important knowledge has been gained toward advancing the
extraction technology of shale gas, such as hydraulic fracturing ("fracking").