The current worldwide energy supply is insufficient to meet the rising demand. As a result,
the energy prices are expected to keep soaring despite the recent increases in a variety of …

The economic production of gas and oil from shales requires repeated hydraulic fracturing
operations to stimulate these tight reservoir rocks. Besides simple depletion, the often …

We carried out a series of long-term creep experiments on clay-and carbonate-rich shale
samples from unconventional gas reservoirs to investigate creep over both relatively short …

Safety assessment of geological nuclear waste repositories is essential for the permanent
disposal of spent nuclear fuels and high-level radioactive waste. The long-term integrity of …

In this paper, a numerical model of the time-dependent behavior of underground caverns
excavated in rock salt is presented. An elasto-viscoplastic constitutive model is utilized to …

Shale is known to exhibit significant creep across spatiotemporal scales. In this work, we
performed indentation and triaxial creep tests on organic-rich Woodford shale and showed …

Viscoplastic deformation of shale is frequently observed in many subsurface applications.
Many studies have suggested that this viscoplastic behavior is anisotropic—specifically …

An understanding of the creep behavior of clayey rocks is considered fundamental for further
development in the fields of nuclear waste underground disposal, underground mine …

To ensure long-term safety and performance, geological nuclear waste repositories require
low-permeability barriers such as bentonite buffers and/or shale host rock. Shale is not only …

We have developed a viscoplastic model that reproduces creep behavior and inelastic
deformation of rock during loading-unloading cycles. We use a Perzyna-type description of …