Preprints
Filtering by Subject: Engineering Science and Materials
Laboratory validation of a new hydro-mechanical energy-based brittleness index model for hydraulic fracturing
Published: 2022-11-30
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Engineering Science and Materials, Mining Engineering, Oil, Gas, and Energy, Petroleum Engineering
Brittleness Index (BI) is a critical parameter characterising the deformation regime of geo-materials, covering the range from purely brittle (fractures) to ductile (plastic flow). A variety of BI models have been developed based on rock properties such as mineralogy, elastic parameters, or stress-strain data. However, very few of them are based on the deformation induced by hydro-mechanical [...]
Spatio-temporal clustering of seismicity enabled by off-fault plasticity
Published: 2021-12-06
Subjects: Applied Mechanics, Civil and Environmental Engineering, Dynamics and Dynamical Systems, Earth Sciences, Engineering, Engineering Mechanics, Engineering Science and Materials, Geophysics and Seismology, Mechanical Engineering, Mechanics of Materials, Other Mechanical Engineering, Physical Sciences and Mathematics, Tribology
While significant progress has been made in understanding earthquake source processes in linear elastic domains, the effect of more realistic rheologies including plasticity is poorly understood. Here, we simulate sequence of earthquake and aseismic slip of a 2D antiplane rate-and-state fault embedded in a full-space elastic-plastic bulk. We show that off-fault plasticity may lead to partial [...]
Linking elastic and electrical properties of rocks using cross-property DEM
Published: 2020-10-22
Subjects: Earth Sciences, Engineering Science and Materials, Geophysics and Seismology, Materials Science and Engineering, Physical Sciences and Mathematics
Joint electrical-elastic rock physics modelling can be instrumental in lowering uncertainty in subsurface reservoir characterisation. Typical electrical-elastic cross-property models, however, are empirical or require an intermediate step of porosity estimation to link a rock's electrical and elastic moduli, which can be error-prone away from well controls. Another outstanding issue in [...]
High Attenuation Recycled Materials as landfill liners (the HARM project) – A new concept for improved landfill liner design
Published: 2020-01-28
Subjects: Bioresource and Agricultural Engineering, Civil and Environmental Engineering, Earth Sciences, Education, Engineering, Engineering Science and Materials, Environmental Public Health, Environmental Sciences, Geochemistry, Geotechnical Engineering, Hydrology, Medicine and Health Sciences, Physical Sciences and Mathematics, Public Health, Soil Science
A new approach in landfill liner design which combines hydraulic containment of leachate with contaminant attenuation to improve the performance of these environmental control systems at landfills is described. The idea is to re-use readily available industrial waste residues (construction and biomass waste) as additives for natural clay liners, wherein the additives have specific properties [...]
Imbibition in porous media: correlations of displacement events with pore-throat geometry and the identification of a new type of pore snap-off
Published: 2019-08-23
Subjects: Chemical Engineering, Civil and Environmental Engineering, Complex Fluids, Dynamics and Dynamical Systems, Engineering, Engineering Science and Materials, Environmental Engineering, Materials Science and Engineering, Mechanics of Materials, Petroleum Engineering, Transport Phenomena
The displacement of a non-wetting fluid by a wetting fluid in porous media, called imbibition, is important in many natural and industrial processes. During imbibition, the wetting fluid invades the pore space through a series of competitions between piston-like displacement, film and corner flow, snap-off, pore bypassing and trapping. Our understanding of these fundamental pore-scale [...]
Cohesive-Zone Effects in Hydraulic Fracture Propagation
Published: 2019-08-22
Subjects: Earth Sciences, Engineering, Engineering Mechanics, Engineering Science and Materials, Environmental Sciences, Geophysics and Seismology, Oil, Gas, and Energy, Physical Sciences and Mathematics
Hydraulic fracture presents an interesting case of crack elasticity and fracture propagation non-linearly coupled to fluid flow. Hydraulic fracture (HF) is often modeled using the Linear Elastic Fracture Mechan- ics (LEFM), which assumes that the damaged zone associated with the rock breakage near the advancing fracture front is small compared to the lengthscales of other physical processes [...]
Lithological, petrophysical and seal properties of mass-transport complexes (MTCs), northern Gulf of Mexico
Published: 2019-02-22
Subjects: Earth Sciences, Engineering, Engineering Science and Materials, Geology, Physical Sciences and Mathematics, Sedimentology
Mass transport complexes (MTCs) are one of the most sedimentologically and seismically distinctive depositional elements in deep-water depositional systems. Seismic reflection data provide spectacular images of their structure, size, and distribution, although a lack of borehole data means there is limited direct calibration between MTC lithology and petrophysical expression, or knowledge of how [...]