Unconfined Compressive Strength Testing

Overview:
 
Rock strength is crucial for designing any field development activity, whether drilling a wellbore, hydraulically fracking or assessing mechanical behavior of a reservoir that is already producing.
Uniaxial Compressive Strength/ Unconfined Compressive Strength (UCS) test is the simplest of the laboratory geomechanics tests that provide measure of strength and mechanical property (Young’s Modulus and Poisson’s Ratio).
No confining pressure, no need for pressure vessel - “unconfined” strength.
The sample diameter can be between 0.75 to 4 inches. with length being twice the sample diameter, per ASTM/ISRM standard.
The example test shown here reports peak stress achieved during the test as UCS of the rock sample with Young’s Modulus being the slope of the stress-strain plot at linear-elastic region, after closure of micro-cracks (if any) and before yield.
 
Recommended Sample Dimensions:
 
Length: 2” Diameter : 1”
Length: 3” Diameter: 1.5”