Projects

Geomechanics for Unconventionals

This area addresses various stages of development of unconventionals, from determination of in-situ stresses, to development of novel completion methods, and reservoir geomechanics during production. The work puts emphasis in departing from linear elastic isotropic models and incorporating realistic tight rock behavior through poroelasticity, anisotropy, visco-plasticity, non-linearity, and micro-porosity with adsorption capacity. Some examples follow:

Hydraulic fracture characterization

• High Resolution HFTS2 slant core imaging through X-ray Computed Micro Tomography (Paper)
• Numerical simulation of effects of hydraulic fracturing on sonic borehole measurements (Paper)

Rock characterization for model input

• Experimental measurements and molecular simulation of carbon dioxide adsorption on carbon surface (Paper)
• Implications of shale anisotropy on determination of stress fracture barriers for tectonically passive and active sites (Paper)
• Poroelastic and adsorptive properties of activated carbon (Paper)
• Anisotropic and nonlinear properties of rock samples in the Vaca Muerta Formation: Experimental measurements and implications on reservoir geomechanics (Paper)
• Poromechanical characterization of a tight-sandstone formation (Paper)
• Vaca Muerta Formation: From laboratory geomechanical characterization to the unconventional reservoir application (Paper)
• Impact of weak rock interfaces on fracturing patterns of synthetic laminated samples (Paper)
• Estimation of Thomsen’s epsilon and delta in a single core using ultrasonic phase and group velocity measurements (Paper)
• Microstructural controls on elastic anisotropy of finely laminated Mancos Shale (Paper)
• Quantifying static and dynamic stiffness anisotropy and nonlinearity in finely laminated shales: experimental measurement and modeling (Paper)
• Analyzing a suitable elastic geomechanical model for Vaca Muerta Formation (Paper)
• Assessment of mudrock brittleness with micro scratch testing (Paper)
• Use of shear-wave anisotropy to quantify the onset of stress-induced microfracturing (Paper)
• Adsorptive-mechanical properties of reconstituted granular coal: experimental characterization and poromechanical modeling (Paper)
• Natural and induced fractures in coal cores imaged through X-ray computed microtomography – Impact on desorption time (Paper)
• Measurement and modeling of adsorptive-poromechanical properties of bituminous coal cores exposed to CO₂: adsorption, swelling strains, swelling stresses and impact on fracture permeability (Paper)
• A transverse isotropic model for microporous solids – Application to coal matrix adsorption and swelling (Paper)

Novel methods for completion

• Propagation of toughness-dominated fluid-driven fractures in reactive porous media (Paper)
• Fracture propagation in heterogeneous porous media: pore-scale implications of mineral dissolution (Paper)

Unconventional reservoir geomechanics

• Permeability changes in coal seams: the role of anisotropy (Paper)
• Geomechanical implications of dissolution of mineralized natural fractures in shale formations (Paper)
• Coupled fluid flow-geomechanics simulation in stress-sensitive coal and shale reservoirs: impact of desorption-induced stresses, shear failure, and fines migration (Paper)
• Desorption-induced shear failure of coal bed seams during gas depletion (Paper)

Carbon Geological Storage

Our work seeks to enable short- and long-term safe storage of carbon dioxide in geological formations. The emphasis of our work is on injection pressure management for geomechanical integrity of the formation and on sealing capacity of caprocks and faults. We also investigate the coupled chemo-mechanical response of target formations to carbonic acid.

The following publications include some examples:

Pressure management to avert fault reactivation and caprock fracturing

• Optimization of CO2 injector location and rate in compartmentalized reservoirs (Paper)
• Optimization of subsurface CO2 injection based on neural network surrogate modeling (Paper)
• CO2 plume and pressure monitoring through pressure sensors above the caprock (Paper)
• Uniaxial strain unloading compressibility of Frio sand: measurements and implications on reservoir pressure management for CO₂ Storage (Paper)
• Wellbore injectivity response to step-rate CO₂ injection: coupled thermo-poro-elastic analysis in a vertically heterogeneous formation (Paper)
• Simulation of fault reactivation using the HISS model (Paper)
• Quantification of a maximum injection volume of CO₂ to avert geomechanical perturbations using a compositional fluid flow reservoir simulator (Paper)

Sealing capacity of caprocks and fault gouge

• Stochastic quantification of CO2 fault sealing capacity in sand-shale sequences (Paper)
• Multiphase CO2-brine transport properties of synthetic fault gouge (Paper)
• Two-phase fluid flow properties of rough fractures with heterogeneous wettability (Paper)
• The effect of organic matter and thermal maturity on the wettability of supercritical CO₂ on organic shales (Paper)
• Textural and compositional controls on mudrock breakthrough pressure and permeability (Paper)
• CO₂ breakthrough – Caprock sealing efficiency and integrity for carbon geological storage (Paper)
• Clay interaction with liquid and supercritical CO₂: The relevance of electrical and capillary forces (Paper)
• Water-CO₂-mineral systems: interfacial tension, contact angle and diffusion – Implications to CO₂ geological storage (Paper)

Chemo-mechanical interactions

• Geochemically induced shear slip in dolomite- and clay-cemented sandstone fractures (Paper)
• Impacts on mechanical strength of chemical reactions induced by hydrous supercritical CO₂ in Boise Sandstone (Paper)
• Geochemical and geomechanical alteration of siliciclastic reservoir rock by supercritical CO₂-saturated brine formed during geological carbon sequestration (Paper)
• Shale-brine-CO₂ interactions and the long-term stability of carbonate-rich shale caprock (Paper)
• Reservoir rock chemo-mechanical alteration quantified by triaxial tests and implications to fracture reactivation (Paper)
• Rock mechanical alteration due to flow of CO₂-charged brine: strength and stiffness of outcrop samples from the Crystal Geyser analog (Paper)
• CO₂-induced chemo-mechanical alteration in reservoir rocks assessed via batch reaction experiments and scratch testing (Paper)
• Discrete element modeling of micro-scratch tests: investigation of mechanisms of CO₂ alteration in reservoir rocks (Paper)
• Discrete element modeling of indentation tests to investigate mechanisms of CO₂-related chemo-mechanical rock alteration (Paper)

Methane Hydrate-Bearing Sediments

The research in this area seeks to measure geophysical, petrophysical and geomechanical properties of hydrate-bearing sediments relevant to geophysical prospection, natural gas production from hydrates, and CO2-enhanched recovery.

Petrophysical and geophysical properties

• Pore-scale evidence of ion exclusion during methane hydrate growth and evolution of hydrate pore-habit in sandy sediments (Paper)
• Ostwald ripening changes the pore habit and spatial variability of clathrate hydrate (Paper)
• Pore-scale determination of relative permeability in hydrate-bearing sediments using X-Ray computed micro-tomography and lattice Boltzmann method (Paper)
• Physical properties of hydrate-bearing sediments (Paper)

Gas production

• Gas permeability, pore habit and salinity evolution during methane hydrate dissociation in sandy sediments (Paper)
• Surface Area Controls Gas Hydrate Dissociation Kinetics in Porous Media (Paper)

CO2-enhanced gas recovery

• P-wave monitoring of hydrate-bearing sand during CH₄-CO₂ replacement (Paper)
• Properties and phenomena relevant to CH₄-CO₂ replacement in hydrate-bearing sediments (Paper)

Geothermal Energy

This research area explores the geomechanical response of geothermal reservoirs to heat extraction accounting for fully coupled thermo-poroelastic response (e.g., undrained response to temperature change). We focus on how geomechanics could limit the recoverable heat energy from conventional hydrothermal reservoirs, multi-fractured enhanced geothermal reservoirs and reservoirs completed with closed-loop wellbores.

Enhanced Geothermal Systems

• Thermal destressing: Implications for short-circuiting in enhanced geothermal systems (In review)
• Geometrical Controls on Thermal Short-circuiting in Multi-fracture Enhanced Geothermal Systems (Paper)

Thermo-poroelasticity

• Depth dependent thermo-poro-elastic response of geothermal reservoirs during heat extraction (Paper)

Reservoir Geomechanics

This research area explores geomechanics problems in recovery of hydrocarbons from conventional reservoirs with advanced experimental tools and numerical methods.

Geomechanics for EOR

• Coupled CFD-DEM modeling of immiscible fluid injection into granular media (Paper)
• Experimental study of the effects of non-Newtonian polymers on fracture opening and leak-off patterns (Paper)
• Simulation of polymer injection in granular media (Paper)
• Impact of suspended solids on initiation of fluid-driven fractures in granular media (Paper)
• Fluid-driven fractures in granular media: new insights from numerical investigations (Paper)

Pressure Depletion

• Grain- to reservoir-scale modeling of depletion-induced compaction and implications on production rate (Paper)

Funding and Sponsors

Completed Projects