Brazilian Tensile Strength Test - Post-failure Behavior of Jurassic and Cretaceous Shales from Svalbard
M. Abbas, B. Bohloli, N.H. Mondol and L. Grande
Event name: 77th EAGE Conference and Exhibition 2015
Session: Geomechanics I
Publication date: 01 June 2015
Info: Extended abstract, PDF ( 1.17Mb )
Price: € 20
This study presents results of indirect tensile tests on cap rock shale samples from Svalbard CO2 storage pilot. It elaborates on tensile strength and the relationship between loading direction and post-failure behaviour of cap rock shale samples. Several test plugs were sampled from Jurassic and Creataceous Age cores of borehole Dh2, Dh4 and Dh6 from depth range of about 400 to 700 m. Samples were tested both parallel and perpendicular to bedding plane. Result of the tests showed that cap rock shale samples subjected to the Brazilian test in different directions relative to bedding planes differs not only in terms of the peak strength but also in the shape of the post-failure curve. The cap rock shale loaded perpendicular to bedding have higher strength and those loaded parallel with bedding show lower strengths. Samples loaded perpendicular to bedding bear load up to a maximum peak followed by a large drop and never reaches the maximum peak load again. For samples loaded parallel with bedding a maximum load is reached at failure followed by sudden drop, but load can increase to the same or higher level than the initial failure stress.