How do we teach Geomechanics? Manolis Veveakis, Thomas Poulet, Klaus Regenauer-Lieb School of Petroleum Engineering Unconventional Geomechanics Group School of Petroleum Engineering e.veveakis@unsw.edu.au

Geomechanics Geotechnics Landslides Rock properties Tunnel design Engineering Geology Seismology Geophysics Seismic Core logging Soil Mechanics Rock Mechanics Fluid Mechanics Solid Mechanics What is Geomechanics? Geomechanics (from the Greek prefix geo- meaning "earth"; and "mechanics") involves the geologic study of the behavior of soil and rock. The two main disciplines of geomechanics are soil mechanics and rock mechanics. The former deals with the behaviour of soil from a small scale to a landslide scale. The latter deals with issues in geosciences related to rock mass characterization and rock mass mechanics, such as applied to petroleum industry or high depths, tunnel design, rock breakage, and rock drilling. Many aspects of geomechanics overlap with parts of geotechnical engineering, engineering geology, and geological engineering. Modern developments relate to seismology, continuum mechanics, discontinuum mechanics, and transport phenomena. In the petroleum engineering Industry, geomechanics is used to predict important parameters, such as in-situ rock stresses, modulus of elasticity, leak-off coefficient and Poisson's ratio. Reservoir parameters that include: formation porosity, permeability and bottom hole pressure can be derived from geomechanical evaluation. The geotechnical engineer or geophysicist relies on various techniques to obtain reliable geomechanical models. These techniques that have evolved over the years, are: coring, log analysis; well testing methods like hydraulic fracturing, and geophysical sonar methods such as acoustic emission. The problem: Geomechanics seems to be loosely defined!

Established in 1985 as a joint industry/UNSW initiative Image based petrophysical rock properties and EOR (ARC, Industry Consortium) - $500k/year NMR Laboratory (ARC, consortium) - $1mil in 2012; $200k/year since CO2 sequestration (CO2CRC) - $200k/year Unconventionals – CBM, Tight Gas, Shale Gas, Fractured Basement and Geothermal (ARC, DigitalCore, ONGC) - $2.2 mil in 2012 + $4.1 mil in 2014

Teaching: Petroleum Engineering (Honours)

Consulting areas Reservoir appraisal Field development geology Reservoir characterisation Conventional log analysis Log analyses for complex reservoir Formation evaluation Field development Reservoir simulation Reservoir engineering Well test analysis Drill string failure analysis Improved oil recovery Natural gas engineering Drilling engineering Integrated reservoir development studies Carbon Capture and Storage Economic assessment and commercial activities Reserves assessment and certification Arbitration Unitisation Field development planning economics Economic evaluation Oil and gas company and property valuation Oil and gas economic modelling Engineering and Economics

Geo-mechanics vs. Geo-mechanics in Petroleum Engineering! But, do we need Geo-mechanics?

Petroleum Industry is interested in exploiting: Conventional hydrocarbon reservoirs (Multi-phase flow, EOR, permeability measures, core logging, rock typing, seismic inversion etc)  (virtually) No mechanics are required at first order Unconventional reservoirs (shale gas, CSG, CBM etc)  Strong mechanics and multiphysics are required

Conventional reservoir modelling Unconventional Conventional reservoir modelling UN Conventional = Darcy flow in permeable rocks Unconventional = low permeability stimulation to crack brittle rock (Unconventional)2 = unconventional in ductile environment Brittle http://csironewsblog.com/tag/rock/ Ductile Applications to geothermal, shale gas, resources…

Shell Scenario

Unconventional Energy: Shale Gas US Report in Environmental and Energy Politics 22nd of April 2015

Australia’s future: Deloitte ‘Oil and gas reality check 2013’ http://www.deloitte.com/assets/Dcom-BruneiDarussalam/Local%20Assets/Documents/oil_gas_reality_check_2013.pdf

Geo-mechanics vs. Geo-mechanics in Petroleum Engineering! We need multi-physical Geo-mechanics!

Why multi-physics?

What skills we need to develop? From Mathematics: Vector-Tensor algebra and analysis ODE and systems PDE and systems Statistical analysis Bifurcation methods Eigenvalue problems Numerical methods in continuum/stochastic framework Numerical methods in discrete framework …

What skills we need to develop? From Mechanics: Constitutive modelling Experimental verification Solid mechanics: Elasticity and LEFM Solid Mechancis: Plasticity and limit analysis Poromechanics: Fluid flow through porous medium Poromechanics: Poroelastoplasticity Fluid mechanics: Navier Stokes and Viscoplasticity Contact Mechanics/ micromechanics …

What skills we need to develop? From Physics: Reversible/Irreversible Thermodynamics Statistical Physics Material Science (spectrometry, thermography etc) CT scanning Nuclear Magnetic Resonance (NMR) analysis Wave analysis (seismic inversion etc) Geochemistry Petrology …

What skills we need to develop? From Experimental multi-physics (THMC): Mechanical deformation (triaxial etc) Infrared measurements (Temperature) Flow cells (Hydraulic processes) Geochemical measurements

What skills we need to develop? For the industry: Knowledge of the world of industry HSE regulations Project Management Risk Analysis Risk Assessment Risk Management Finance and Economics Expertise in using dedicated FEM software packages (Eclipse, Ansys, Abaqus etc) Seismic inversion …

The pyramid of knowledge Create Evaluate Academia Analyze Apply Understand - Explain Industry Knowledge - Remember Atherton J S (2013) Learning and Teaching; Bloom's taxonomy

Clash of opinions!

Conclusions Highlight state-of-the-art and future research (multiphysics) Equip students with sound basic knowledge, so that they can walk the path by themselves Geo-Mechanics is the fundamental basis of Multiphysics

Thank you!