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

1. 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 University 2 The Technology and Research Center, Oil, Gas and Metals National Corporation (JOGMEC)

2. -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

3. quartz carbonate clay Vapor/fluid liquid solid Water-oil-rock (Enhanced oil recovery) Oil brine rock Sea water quartz carbonate clay Sea water＋ chemical quartz carbonate clay （Young’s equation）

4. Comparison of computational and experimental results

6. The previous results presented in 2008 （北京）

7. Contact angle vs Salinity of brine

8. Observation of oil droplet on micaby AFM (Oil diameter ;400nm)

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

10. The results in 2009 (A preliminary report)

11. h R Macro analyses C10H22 Decane 0.7g/cm3 H2O droplet R = 159 μm h = 20 μm Θ= 28.2° θ/2 method

12. Sample preparation for micro droplet Mica preparation Large emulsion (10 micro m~) Small emulsion (~10 micro m) Make Mica cleavage H2O Cleanup mica surface with water Splash by air compressor Decane Soak mica in Decane for 1 day Magnetic stirrer Ultrasonic bath Decane H2O droplet mica H2O 5m Decane 500ml H2O ~1ml Decane 100ml Naturally deposition for 1 hour Contact angle measurement

13. Mica surface in decan (AFM) Cantilever: k=0.01 Pressure: 2.5nN Scan rate: 0.5Hz Root mean square Roughness Roughness; 0.75nm ⇒smooth surface in nanoscale 1μm×1μm

14. Water droplet in decan (AFM) Cantilever: k=0.01 Pressure: 2.5nN Scan rate: 0.5Hz H2O droplet 5μm×5μm Rms roughness; 0.32nm

15. Contact angle of water droplet in decan h R 5μm×5μm θ/2 method R=2.109 micro m H=92.25 nano m Contact angle 12.7 degree (θ/2 method)

16. Contact angle of water droplet in decanon mica surface (f=2.5nN) Cantilever: k=0.01 Pressure: 2.5nN Scan rate: 0.5Hz

17. × Effect of cantilever pressure on contact angle Is it a realcontact angle? F=2.5nN F=25nN R~10 micro m h=456.6 nano m Contact angle= 10.7° Cantilever: k=0. 1 Pressure: 25nN Scan rate: 0.5Hz

18. Contact angle of water droplet in decanon mica surface C.Pressure(low) C.Pressure(high)

19. AA=15.4 micro m cantilever F=25nN Real surface Apparent surface Effects of scanning pressure Topography Error signal (Differential calculus)

20. ＊ Effects of scanning pressure Force curve near water droplet cantilever Retract Approach Approach Retract Decan on mica surface In H2O droplet

21. Correction of contact angle Error signal⇒contact angle correction Force curve⇒height correction

22. Contact angle vs. oil size (AFM) Modified Young’s equation Similar value to the observed one in macro scale

23. Vertical Scan Interferometry (VSI)

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

26. Water droplet in decan (VSI) Width：9.9μm Height：0.52μm Contact angle　＝　12.0°

27. H2O Hexane CH3(CH2)4CH3 α-Quartz 5nm hydrophilic no hydrophilic

28. Thank for your attention.