Deploying Nanotechnology in Oil and Gas Operations: Pore-Scale Modelling of Nanoparticle Adsorption-Desorption Behavior Boya Subhono, Mark Wilson, Nik Kapur,

Anne Neville, Harvey Thompson

University of Leeds, UK

PRESENTATION TOPICS

• Company Overview (2-3 minutes);

• Problem Description;

• Methodology;

• Conclusion;

• Future work

Institute of Engineering Thermofluids, Surfaces & Interfaces (iETSI)

• Largest insitute within the School of Mechanical Engineering at University of Leeds

• Top rated under UK Government Research Assessments

• Core strengths in

– Corrosion and erosion-corrosion

– Mineral scale management

– Combustion

– Tribology

– CFD

– Optimization

– Metrology

iETSI – Corrosion and Erosion-Corrosion

• Corrosion – Electrochemical assessment

– Corrosion in oil and gas (sweet and sour)

– Marine corrosion

– Evaluation of pitting and other localised corrosion

– Stainless steels, Cu-based alloys, CRAs

• Erosion-corrosion – Erosion-corrosion assessment

– Erosion-corrosion modelling

– Cavitation-corrosion

– Mitigation using chemicals

• Coating development and assessment – Assessment of damage mechanisms on composite coatings

– Development of new HVOF coatings

iETSI – Mineral scaling

• Surface deposition – Kinetics and mechanisms of surface deposition and adhesion

– Adhesion assessment by fluid flow analysis

– Calcium carbonate and barium sulphate

• Wide Angle X-Ray Diffraction (WAXRD) – Tube blocking tests with online sensing

– In situ measurement of crystal formation (Brookhaven, US)

• Anti-fouling surfaces – Assessment of surfaces for low fouling

– Surface modification by chemical and physical means

iETSI – Advanced Coatings Design Lab

• State-of-the-art commercial scale PVD system

– Application-driven research approach

– Synergy with tribology and surfaces/interfaces research

iETSI – Extensive surface analysis capability

0

1.8 mm

50

25

2.3 mm

μm

iETSI – Oil and Gas Education

• MSc Oilfield Corrosion Engineering

– Tailored MSc for the oil & gas industry

– Provides students with skills needed to practise as Corrosion Engineers in the oil & gas sector

– Led by Professor Anne Neville

• Modules include

Corrosion Corrosion Prediction

Mettalurgy & Welding Flow-induced Corrosion

Surface Engineering Coatings, linings & non-metallics

Corrosion Inhibition Risk Assessment

Corrosion Monitoring Erosion-Corrosion

NANOTECHNOLOGY IN OIL AND GAS

• Rapidly growing interest in nanotechnology in oil and gas industry, as highlighted by recent SPE conference

• Example applications include using nanoparticles for

– Agents for modifying surface wettability

– Mobilization agents for recovery of residual oil

– Enhancing mineral scale management systems

– Enhanced drilling fluids

– Water shut-off

NANOPARTICLE TRANSPORT

• Problem in using nanoparticles downhole is understanding and controlling nanoparticle transport through porous media

• Nanoparticles need to be delivered to the required location

• Nanoparticles need to adsorb/desorb to/from surfaces of they are to change surface properties e.g. wettability – effect of flow?

• Experimental corefloods can give some idea of macroscopic effects and changes in behavior, but give no indication of pore-level coverage or mechanisms

NANOPARTICLE TRANSPORT

Inject e.g.

nanoparticle

suspension

Monitor

effluent

Rock core sample

What is the

distribution and

coverage inside?

• Pore-scale CFD can help explore nanoparticle transport and adsorption and desorption

NANOPARTICLE TRANSPORT

AIM & METHODOLOGY

• Aim is to explore the effect of flow on adsorption

• Consider flows in idealized pore-scale geometries

• Finite element analysis

• Build up understanding of influence of flow and geometry on adsorption and desorption

• Infer behavior in much larger pore networks

MODEL

• Treat nanoparticle suspension as a dilute suspension with a continuous concentration field

• Navier-Stokes equations for (steady) fluid flow

• One-way coupling of (time-dependent) advection-diffusion equation for nanofluid concentration

• Freundlich adsorption-desorption model

GEOMETRY CONSIDERED

• To isolate effect of inclination of surface to main flow direction, consider:

90 ͦᵒ

0ͦᵒ 180 ͦᵒ

0ͦᵒ

45ᵒ 90ᵒ 135ᵒ

180 ͦᵒ

Active adsorption surfaces Flow

α

Flow direction

GOVERNING EQUATIONS AND BOUNDARY CONDITIONS

Surface concentration of adsorbed species Bulk concentration

GOVERNING EQUATIONS AND BOUNDARY CONDITIONS

SIMULATION CONDITIONS

Description Value Unit

Initial concentration in place 0 mol/m3

Inlet discharge concentration 1000 mol/m3

Adsorption rate constant 1.00E-06 m3/(s.mol)

Desorption rate constant 1.00E-09 1/s

Water Diffusivity 1.60E-09 m2/s

Channel width 1.00E-05 m

Simulation time length 2.00E+03 s

Particle diameter 1.20E-09 m

Inlet pressure 3 Pa

Outlet pressure 0 Pa

RESULTS

Velocity field

RESULTS

Concentration field at steady state

RESULTS

Bu

lk c

oncentr

atio

n a

t th

e a

ctive s

urf

ace

Arc length around octagon

Higher

concentration

at the edge

that is

perpendicular

to and facing

the flow

RESULTS

Re

du

ctio

n in c

oncen

tration

of adso

rbed

sp

ecie

s c

om

pare

d to s

urf

ace facin

g flo

w

time

CONCLUSIONS

• CFD offers the opportunity to explore nanoparticle penetration and distribution within pore networks

• To begin, simple geometries considered to explore local effects

• Through variations in the bulk concentration at the surface, fluid flow has been shown to influence the local adsorption of nanoparticles

• However, flow is not explicitly included in the material balance (adsorption-desorption) equation

FUTURE WORK

• Adsorption experiments using micromodels to verify the correct adsorption-desorption model to be used

• Extension to more complicated pore networks

• Extension to 3D

ACKNOWLEDGEMENTS

This work was supported by the Flow Assurance and Scale Team (FAST) Joint Industry Project

Thank you for your attention