Elastic Anisotropy Reversal During Brittle Creep in Shale

Mechanical properties of shale-gas reservoir rocks — Part 2: Ductile creep, brittle strength, and their relation to the elastic modulus

We studied the elastic moduli, ductile creep behavior, and brittle strength of shale-gas reservoir rocks from Barnett, Haynesville, Eagle Ford, and Fort St. John shale in a series of triaxial laboratory experiments. We found a strong correlation between the shale compositions, in particular, the volume of clay plus kerogen and intact rock strength, frictional strength, and viscoplastic creep. V...

Creep: Time‐dependent brittle deformation in rocks

Experii\iental Deteri\iiination of Elastic Anisotropy of Berea Sandstone, Chicopee Shale and Chelmsford Granite

We use the ultrasonic transmission method to measure P-, SH-, and SV-wave velocities for Chelmsford Granite, Chicopee Shale, and Berea Sandstone in different directions up to 1000 bars confining pressure. The velocity measurements indicate that these three rocks are elastically anisotropic. The stiffness constants, dynamic Young's moduli, dynamic Poisson's ratios, and dynamic bulk moduli of the...

Mechanical properties of shale-gas reservoir rocks — Part 1: Static and dynamic elastic properties and anisotropy

Understanding the controls on the elastic properties of reservoir rocks is crucial for exploration and successful production from hydrocarbon reservoirs. We studied the static and dynamic elastic properties of shale gas reservoir rocks from Barnett, Haynesville, Eagle Ford, and Fort St. John shales through laboratory experiments. The elastic properties of these rocks vary significantly between ...

Brittle creep, damage and time-to-failure in rocks

We propose a numerical model based on static fatigue laws in order to model the time-dependent damage and deformation of rocks under creep. An empirical relation between time-to-failure and applied stress is used to simulate the behavior of each element of our finite element model. We first review available data on creep experiments, in order to study how the material properties and the loading...