Observations of Microdrop Decan and Oil on Mica Surface by AFM and VSI.

Ueda, A.1, Kunieda, M.1, Fukunaka, Y.1, Liang, Y.1, Matsuoka, T.1 and Okatsu, K.2

1 Kyoto University2 The Technology and Research Center, Oil, Gas and Metals National Corporation (JOGMEC)

-Background “EOR⇔NANO”-

High recovery=EOR (Enhanced Oil Recovery)

⇒ Viscosity, Fluidity, Substitution efficiency…

micro-phenomena controls the wettability (contact angle, surface tension)

in oil-mineral-fluid

quartzquartz carbonatecarbonate clayclay rockrock

OilOil

quartzquartz carbonatecarbonate clayclay

Sea waterSea water

quartzquartz carbonatecarbonate

Sea waterSea water ＋＋chemicalchemical

brine

Water-oil-rock (Enhanced oil recovery)

lv

slsv

Vapor/fluid

solid

liquid Ylvslsv cos（ Young’s equation ）

clayclay

Oil

Mineral

Brine

Oil

Mineral

Brine

Brine

Oil

Oil

Mineral

MD

Ab initio

Calculations Experiment

+

Contact angle(macro)

Mineral

Oil

Brine

Mica/Quartz

・Light oil・Heavy oil・Crude oil

Analyses of oil-water-mineral interface

Flow test (lab)

Flow test (Field)

Zeta potential

Experiments

Oil

Contact angle(nano)+Force

Comparison of computational and experimental results

5

5

Force curve

AFMInterface equilibrium

Contact angle

Force curve

ζ potential

MD

Fluidity

LBMContact angle under low P,T

Contact angle under high P,T

VSI

ζ potential

Experiment Simulation

yes

Wettability

Salinity

electric double layerDLVO

Adhesion, cohesion

Contact angle

Contact angle

Geochemical behavior in pore and fracture

OIL-PAC

The previous results presented in 2008 （北京）

Contact angle vs Salinity of brine

20

30

40

50

60

70

0 10 20 30

Oil volume μ L（ ）

Con

tact

ang

le（○

） Distilled water

Sea water

Cruide oil Higashi-Niigata 　　

Locality Niigata

Density(g/cm3) 0.784

API 49.0

Velosity(30℃) 1.2

Observation of oil droplet on mica by AFM

(Oil diameter ;400nm)

1

Sapphire disc

Petroleum droplet

VSI measurement

~4.2

Observation of oil droplet by VSI (Vertical Scanning Interferometry) in distilled water at 25℃ 　 and 1 atm

9

CCD cameraPC

Laser/White light

= 532 nm

Piezo actuator

Phase shift interferometry

Thin section sample

The results in 2009(A preliminary report)

Macro analyses

R

h

2

Decane

H2O droplet

R

h2arctan2

θ/2 method 　

R = 159 μmh = 20 μm

Θ= 28.2°

C10H22

0.7g/cm3

mica

H2O droplet

Decane

Naturally deposition for 1 hour

Cleanup mica surface with water

Make Mica cleavage

Splash by air compressor

Soak mica in Decane for 1 day

Mica preparation

Contact angle measurement

Small emulsion(~10 micro m)

Large emulsion(10 micro m~)

Decane

H2O

Ultrasonic bath

Magnetic stirrer

Sample preparation for micro droplet

dw

Cantilever: k=0.01Pressure: 2.5nNScan rate: 0.5Hz

1μm×1μm

21

hhn

Rrms

Root mean square Roughness

Roughness; 0.75nm

⇒ smooth surface in nanoscale

Mica surface in decan (AFM)

5μm×5μm

Rms roughness; 0.32nm

Cantilever: k=0.01Pressure: 2.5nNScan rate: 0.5Hz

H2O droplet

Water droplet in decan (AFM)

R=2.109 micro mH=92.25 nano mContact angle

12.7 degree (θ/2 method)

Contact angle of water droplet in decan

5μm×5μm

R

h

2

θ/2 method

R

h2arctan2

Contact angle of water droplet in decan on mica surface (f=2.5nN)

Cantilever: k=0.01Pressure: 2.5nNScan rate: 0.5Hz

Effect of cantilever pressure on contact angle

Is it a real contact angle?

R~10 micro mh=456.6 nano mContact angle= 10.7°

F=2.5nN

Cantilever: k=0. 1Pressure: 25nNScan rate: 0.5Hz

F=25nN

×

Contact angle of water droplet in decan on mica surface

C.Pressure(low)

C.Pressure(high)

Error signalTopography

Effects of scanning pressure

Real surfaceApparent surface

cantilever

F=25nN

AA=15.4 micro m

(Differential calculus)

Effects of scanning pressure

cantilever

Force curve near water droplet

ApproachRetract

Decan on mica surface In H2O droplet

Approach

Retract

＊

Correction of contact angle

Error signal⇒ contact angle correctionForce curve⇒ height correction

RlvY

coscos

degree1.26

N1097.2 9

Y

N/m053.0lv

Contact angle vs. oil size (AFM)

Modified Young’s equation

Similar value to the observed one in macro scale

Waterchiller

Optical bench

Peltiercooler

HEPA filter

VSI optics(RSI, MM5500)

Wind shield(metal frame)

Active stage

Air-conditionerAmbient: 22± 0.5 ℃<40 % humidity

Air

Vertical Scan Interferometry (VSI)

= 520 nm

fluid

20x

20xreferencemirror

compensator

PZT scanning

interferogram

beam-splitter

mica substrate

lens

lens

stage unit for reference mirror

lens

Vertical Scanning Interferometer HT-HP cell and In-situ optics

x’x

0

500

1000

1500

2000

2500

3000

0 50 100 150 200

Distance (µm)

x-x’ profile

p1 p2

He

igh

t (n

m)

20µm

（２２℃、40µl/min）

CVD diamondsubstrate

Cell body(titanium)w/ heater

Sample holder(titanium)

Calcite substrateSapphire substrate(cell window)

VSI

PTFE + metal coilseal

Gold wire(spacer)

Reaction cell for high T and P (~200℃, ~20MPa)

Width ： 9.9μmHeight ： 0.52μm

Contact angle 　＝　 12.0°

Water droplet in decan (VSI)

27

hydrophilic no hydrophilic

5nm

α-Quartz

HexaneCH3(CH2)4CH3

H2O

Thank for your attention.