Measure what is measurable, and make measurable what is not so.
– Galileo Galilei –
NER AutoLab 1500
This is the work-horse of the RDL a multipurpose triaxial apparatus that can reach 200 MPa confining pressure and 125 deg C. We use this machine to measure ultrasonic velocities, permeability, and other physical properties of rocks. The apparatus can be equipped with various instruments including high pressure syringe pumps to control the pore pressure.
Bevo-Q and WIGED apparatus – seismic wave attenuation in liquids
Bevo-Q resembles the mascot of UT Austin – Bevo the longhorn and it is an apparatus to measure the attenuation of seismic waves in liquids. Such an instrument can measure attenuation at frequencies between 0.01 and 10 Hz.
To study the attenuation in bubbly liquids and the Wave-Induced-Gas-Exsolution-Dissolution attenuation mechanism we have a dedicated instrument that records the deformation of a gas bubble in a liquid undergoing a variation of pressure.
- McCann, M.*, Tisato, N., & Spikes, K. (2019) Low-frequency attenuation measurements of fluids. In SEG Technical Program Expanded Abstracts 2019 (pp. 3598–3602). San Antonio, Texas: Society of Exploration Geophysicists. DOI: 10.1190/segam2019-3193361.1
Energy Controlled Rotary Shear (ECoR)
The ECoR is a rotary shear apparatus that takes advantage of a clock spring to impose a shear stress boundary condition on a couple of cylindrical samples. The apparatus accumulates elastic energy in the clock spring until slip initiates, translating the elastic energy into displacement.
- Conrad, E. M.*, Tisato, N., Carpenter, B. M., & Di Toro, G. (2023) Influence of Frictional Melt on the Seismic Cycle: Insights From Experiments on Rock Analog Material. Journal of Geophysical Research: Solid Earth, 128, (19 pages). DOI: 10.1029/2022JB025695
X-RETTA – combining Rock-physics with X-ray imaging – in collaboration with the UTCT
The X-Ray Transparent Tri-axial Apparatus (X-RETTA) allows us to load cylindrical rock samples triaxially while simultaneously embedding them inside Micro-scale X-ray Computed Tomography (microCT) scanners as shown in the images below. This is possible due to the small footprint of the device and the use of flexible hydraulic tubing that is used to control the hydraulic fluid pressures of different X-RETTA chambers. Given a cylindrical rock sample with a diameter of 25mm (~1 inch), the X-RETTA is capable of producing an axial load of ~160MPa, and confining pressure of about ~ 21MPa. Also, the X-RETTA allows for accessing the sample pore pressure. This allows for either drained or undrained experimental configurations. Finally, we built a custom permeameter that integrates with the X-RETTA to measure the permeability of the sample while the apparatus is mounted inside the microCT scanner at UTCT.
The RDL equipment includes i) a 4 channels 100 MHz sampling rate digital oscilloscope, ii) a 10 MHz 8 channels 12 bits oscilloscope for acoustic emission (AE) recording, iii) a 100 MHz 4 channels 16 bits oscilloscope, iv) two 20 MHz function generators, v) 3 pulse generators for ultrasonic transducers, vi) 9 Olympus ultrasonic transduces for measurements of Vp and Vs in samples with diameters greater or equal 1/2 inches, vii) a set of 5 acoustic emissions (AE) preamplifiers and sensors, and vii) two high precision (5.5 and 6.5 digits) multimeters.
Analytical instruments and computational facilities
The RDL has i) a helium pycnometer to measure sample porosity, ii) a BET surface area analyzer (autosorb), iii) a falling-head permeameter.
Several Linux workstations with multiple cores, GPUs, and up to 256 GB of memory and the Texas Advanced Computing Center (TACC).
Rock preparation lab
To prepare our experiments and core plugs, the RDL has a dedicated room, that accommodates a fume hood, a lathe with surface grinder, a milling machine, two drill presses and other tools.