Rock Physics & Geomechanics

The research of the group focusses on intergrating physical experiments, as per the capabilities outlined below, with geological data from thin section analyses using optical and scanning electron microscopy.  We also compare measured data with theoretical predictions from rock physics and rock mechanics models. We regularly host visiting students and interns from the UK and overseas.

Equipment

Uniaxial press: Uniaxial rock deformation apparatus (Controls Testing) with axial force up to 2000 kN.  We can measure stress, strain and elasticity during deformation.  This device takes cylindrical or block samples over a range of sizes.  We are adding acoustic emission detection to this device.
Triaxial cell and rock physics assembly: Triaxial rock deformation apparatus (Sanchez Technologies) with confining pressure to 250 MPa, axial stress to 1500 MPa and temperature to 200°C.  We can measure stress, strain, elasticity, acoustic velocities, permeability and pore fluid volumes during deformation.  We are adding acoustic emission detection to this device.  Loading can be either constant strain rate or constant stress.  This device takes cylindrical core plug samples 25 mm in diameter and up to 60 mm long.  This apparatus has been funded by the Oil & Gas Innovation Centre (OGIC, part of the SFC) but is available for a wide range of projects funded from various sources.
Hydrostatic permeameter: Hassler sleeve nitrogen permeameter using constant flow rate for 1”, 1.5” and 40 mm diameter core plugs; High pressure nitrogen permeameter using constant flow rate, with confining pressure and fluid pressure to 250 MPa (36 kpsi). 1” and 20 mm diameter core plugs; High pressure water permeameter using transient decay or constant flow rate, with confining pressure and fluid pressure to 250 MPa (36 kpsi). 1” and 20 mm diameter core plugs [under construction]
Jones porosimeter and permeameter:  helium porosimeters for 1” and 1.5” diameter core plugs
Mercury injection porosimetry: Mercury injection porosimeter (Autopore IV 9500 from Micromeritics) for capillary pressure and pore throat size distributions
Ultrasonic wave velocities: P- and S-wave velocity measurements at ultrasonic (~1 MHz) frequencies on dry samples. Sample holders for axial and radial measurements to quantify velocity anisotropy; P- and S-wave velocity measurements at ultrasonic (~1 MHz) frequencies on fluid saturated samples, at confining pressures up to 70 MPa (10 kpsi) and fluid pressures to 17 MPa (2.5 kpsi). Pressure vessel can hold up to 5 x 1.5” cores simultaneously [under construction]
Fracture pattern quantification code: Semi-automate routine to analyse fracture images using MatLab (see software& tools section)
Handheld spectral gamma ray detector: For mapping shale and other formations.
Helium pycnometer: Standard gas pycnometer using Helium for rock surface area determination.

Current Projects

- We have active research programmes in permeability anisotropy, rock physics of volcanics and volcaniclastics, the links between evaporite fabrics and anisotropies, and hydrothermal alteration of fractured granites.
- Staff and students interested in rock physics and geomechanical measurements are welcome to use the laboratory. Laboratory fees for consumables and staff time are generally paid for via research grant income, or industrial sponsorship. Please contact the lab manger for more information.