Rossen Sedev

Nanotechnologies to Optimise Productivity from Unconventional Reservoirs

(rossen.sedev@unisa.edu.au)

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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