Rossen Sedev
Nanotechnologies to Optimise Productivity from Unconventional Reservoirs
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DMITRE-IMER Meeting of the Roundtable for Unconventional Gas Projects in South Australia 2-4 December 2013, National Wine Centre, Adelaide
The Wark
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RESEARCH EXPERTISE Mineral Processing Research on the science and technology of primary mineral extraction. Colloids and Nanostructures The science and engineering of materials and interfaces at the micro and nano level. Bio- and Polymer Interfaces Colloid, interfacial and surface science applied to biological, biomedical and pharmaceutical systems.
The Ian Wark Research Institute (The Wark) is a flagship institute of the University of South Australia dedicated to the study of the interfacial aspects of minerals and materials.
People
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A/Prof Rossen Sedev wettability, surface forces, physical chemistry of Interfaces, porous media, ionic liquids
Prof Naba K. Dutta polymer science, physical chemistry & materials engineering
Dr Catherine Whitby formation & stability of emulsions, rheology of jammed materials, powders
Prof Thomas Nann nanochemistry, surface & colloidal chemistry, photoelectrochemistry
Prof Dayang Wang particles at interfaces, synthesis & self-assembly, hydrogels
Prof Jonas Addai-Mensah solid-liquid processing & separation, minerals, materials & waste liquor processing
Approach
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Rheology & Formulation of
Fracturing Liquids
Wettability & Interactions in
Shales
Diagnostic Rock Characterization &
Surface Modification
Interfaces, Particles, Surface Engineering,
& Nanomaterials
Advanced Interfacial Engineering
Well Productivity
Colloid Chemistry of Fracturing Fluids
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Flow in confinement, Jamming
Formulation, Stability
Outlook & Challenge
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A viscoelastic fluid carrying coarse particles (proppant) is used to stimulate gas and oil production by fracturing the rock. Well productivity depends on fracture length and open pathways available to hydrocarbons.
The Challenge: • Develop tools to probe the flow of fluid microstructures in confined space. • Characterise the use of recycled/high-salinity water.
Reinicke et al (2010) Chem Erde
Flow of a Microstructured Fluid in Confined Space
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Maps of velocity profiles and coarse particle settling in model fluids as functions of channel width and wettability
• Fluorescent dyes stain fluid and coarse particles. • Tracer particles to track fluid flow. • Channels of different size and wettability. • Confocal fluorescence microscopy to visualise fluid
microstructure as fluid is pumped into the channel.
Whitby et al (2013) Soft Matter
A confined emulsion
Fluid Flow at Higher Temperature & Pressure Testing of fracturing fluid mechanical response and stability at
higher shear rates, temperatures and pressures
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• Determine the viscosity and elasticity of fracturing fluids under shear, temperature and pressure regimes encountered in wells.
• Equipment available: Rheometrics Dynamic Stress Rheometer (maximum temperature 180 °C, maximum pressure 750 psi).
GASINLET OUTLET
Peltier unit Couette geometry High pressure Couette
Fracturing Fluids with Recycled Water
• Freshwater shortages in Australia necessitate the use of recycled water. • Seawater can be used in guar gum (borate cross-linked) fracturing fluids for
offshore drilling (Harris & van Batenburg 1999). • The “Flowback water” and “produced water” have high salinity (metallic ions,
inorganic anions) and contain organics (oil, scale removers, biocides, corrosion inhibitors).
• This complex chemistry may affect the performance of the fracturing fluid.
Rheological characterisation of the effects of recycled water chemistry on fracturing fluid performance
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Garcia & Whitby (2012) Soft Matter
Particle-Stabilized Emulsions
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A better understanding of particle interactions with oil/water and gas/water interfaces provides opportunities for better stabilization or more effective destabilization of emulsions and foams.
Modify the surfaces of particles to manipulate their interfacial behaviour and stabilizing action
300 nm
A hydrogel ball stabilized with silica nanoparticles
Wu et al (2011) Adv Mater Whitby et al (2011) Soft Matter
Hydrogel-Based Composite Materials
Various molecules or nanoparticles can be encapsulated in hydrogel microparticles which can then be transferred across oil/water interfaces. No chemical modification of the loaded guests and hydrogel hosts is needed.
A hydrogel ball loaded with fluorescent nanoparticles
40 µm
Advanced multifunctional formulations based on hydrogels
Bai et al (2011) Adv Mater
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Design of Improved Fracturing Fluids
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Particles Surfactants
Polymers
Sedev & Exerowa (1999) ACIS
Mpofu et al (2004) JCIS
O’Shea & Tallon (2011) CS A
Clays & Organic Matter Distribution
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Jiang (2012) Clay Minerals in Nature
Mineralogy & Porosity
Bulk Structure & Surface Analysis
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Pore distributions + Chemical Imaging
Chemically enhanced 3D imaging of particles internal volume & structure:
Quantitative XRD/QEMSCAN, CT, XPS, ToF-SIMS, EXAFS & Synchrotron studies
1 mm
0.8 mm
0.5 mm
QEMSCAN
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QEMSCAN = Quantitative Evaluation of Minerals by Scanning Electron Microscopy
• The QEMSCAN system is a Scanning Electron Microscope (Zeiss Evo 50 SEM platform) combined with 2 silicon drift X-ray spectrometers (Bruker) and iDiscover v. 5.2 software (FEI).
• It allows analysis of drill cuttings, thin sections and powders. • The phase identification is based on chemical composition (EDX) and the BSE
(backscattered electrons) brightness. • It measures both crystalline and non-crystalline phases with distinct elemental
composition. • It provides quantitative mineral distribution and the association characteristics as
well as textural information such as laminations, size and shape of the minerals, organic phases and pores.
Goodall et al (2005) Miner Eng
Microstructure Characteristics (Tomography)
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2D 3D
Visualized internal porosity changes
1 mm
pores 1 mm
wet
wet
dried
dried wet
cracks
air-dried
Particles Particle Sections
Wettability & Interfacial Forces
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Particle-Particle Interactions
Particle-Wall Interactions
Wettability of Shales
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Pore size [m]
Contact Angle
Pressure [atm]
2×10-6 0° ~1
2×10-9 0° 1400
2×10-9 70° 490 r
2 cosCPrγ θ=
Physical Chemistry • Contact angle • Spontaneous imbibition • Pigment extraction • Optical microscopy
+ Petrophysics
• Dielectric spectroscopy • NMR • SEM • Fluorescence microscopy
= wettability characterization
CPγ
WS
Morrow & Mungan (1971) Rev IFP
Collaboration with CSIRO Petroleum
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Joint Industry Project “Integrated Predictive Evaluation of Traps and Seals (IPETS)”
Dr David Dewhurst geomechanics, shale behaviour, rock mechanics
Dr Ben Clennell petrophysics, gas hydrates, marine & structural geology
Borysenko et al (2009) J Geophys Res B
SFA & AFM
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Surface Force Apparatus Atomic Force Microscopy
Diversity
Surface Forces Between Interfaces
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van der Waals forces
Steric forces
Hydration forces
Double layer forces
Drummond & Israelachvili (2004) J Petrol Sci Eng
Mica-Crude Oil-Mica
a) approach
b) retraction
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“These represent opportunities for fundamental research that can have a direct impact on an important and developing industrial process.”
Yethiraj & Striolo (2013)
Colloid Chemistry of Fracturing Liquids
Clay & Organic Matter Distributions
Interactions with Rock Surfaces
Micro- and nanostructure characterisation Surface chemistry
Formulation of fracturing liquids Flow behaviour, colloidal chemistry
Wettability, interfacial forces Alteration by fluid contact