Novel true triaxial apparatus applied to the study of sand mass production under anisotropic stress conditions.

Using a novel true triaxial setup, sand production tests on hollow quasi-cylinder
Castlegate sandstone specimens have been performed on irreducible water saturated specimens
with oil flow under varying levels of axial and lateral stress anisotropy, obtaining sand onset and
rate. The experimental results have been compared with analytical models for sand onset and sand
rate predictions. Also, a new model that includes the effect of axial and lateral stress anisotropy has
been developed and calibrated on the test results.