Abstract
Most clastic reservoirs display an intermediate type of wettability. Intermediate wettability covers several local wetting configurations like fractional wet and mixed-wet where the oil-wet sites could either be in the large or smaller pores. Clastic reservoirs show a large variation in fluid flow properties. A classical invasion–percolation network simulator is used to investigate properties of different intermediate wet situations. Variation in wetting properties like contact angles, process dependent contact angles, contact angle distribution, and fraction of oil wet sites are investigated. The fluid flow properties analysed in particular are residual oil saturation and normalized endpoint relative permeability. Results from network modelling have been compared to reservoir core analysis data. The network models applied are at the capillary limit, while the core flood results are clearly viscous influenced. Even though network modelling does not cover all the physics involved in fluid displacement processes, results show that data from simulations are sufficient to present trends in fluid flow properties which are comparable to experimental data.
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Abbreviations
- Sor:
-
Residual oil saturation
- Swi:
-
Irreducible water saturation
- Krw(Sor):
-
End-point relative permeability
- MWL:
-
Mixed wet large
- FW:
-
Fractional wet
- MWS:
-
Mixed wet small
- I o :
-
Oil wettability index
- I w :
-
Water wettability index
- I AH :
-
Amott Harvey wettability index (I w–I o)
- I USBM :
-
USBM wettability index
- α:
-
Oil-wet fraction
- α num :
-
Oil-wet fraction by number
- α vol :
-
Oil-wet fraction by volume
- α crit :
-
Critical oil-wet fraction
- α num,crit :
-
Critical oil-wet fraction by number
- αvol,crit :
-
Critical oil-wet fraction by number
- θ:
-
Contact angle
- θ ww :
-
Contact angle in the water-wet pores
- θ ow :
-
Contact angle in the oil-wet pores
- θ a :
-
Advancing contact angle
- θ cw :
-
Critical water-wet contact angle
- θ co :
-
Critical oil-wet contact angle
- r :
-
Radius
- σ ow :
-
Interfacial tension between oil and water
- β:
-
Angle of pore corner
- P c :
-
Capillary pressure
- P o :
-
Pressure oil phase
- P w :
-
Pressure water phase
- A i :
-
Arbitrary numbers
- x i :
-
Random number between 0 and 1
- ΔS ws :
-
Change in water saturation during spontaneous water imbibition
- ΔS wf :
-
Change in water saturation during forced water imbibition
- ΔS os :
-
Change in oil saturation during spontaneous oil imbibition
- ΔS of :
-
Change in oil saturation during forced water imbibition
- A :
-
Area under curve
- D :
-
Network dimension
- z :
-
Co-ordination number
References
Amott E. (1959). Observations relating to the wettability of porous rocks. Trans AIME. 216: 156–162
Bakke S. and Øren P.E. (1997). 3D Pore-Scale Modelling of Sandstones and Flow Simulations in the Pore Networks. SPE J. 2: 136–149
Blunt M.J. (1997a). Effects of heterogeneity and wetting on relative permeability using pore level modeling. SPE J. 2: 70–86
Blunt M.J. (1997b). Pore level modeling of the effects of wettability. SPE J. 2: 494–510
Blunt M.J. (1998). Physically-based network modelling of multiphase flow in intermediate-wet porous media. J. Petrol. Sci. Eng. 20: 117–125
Boneau, D.F., Clampitt, R.L.: A Surfactant system for the oil-wet sandstone of the North Burbank Unit. J. Petrol. Technol. May, 501–506 (1977)
Dixit, A.B., McDougall, S.R., Sorbie, K.S.: A Pore-Level Investigation of Relative Permeability Hysteresis in Water-Wet Systems, Paper presented at the SPE International Symposium on Oilfield Chemistry, held in Houston, Texas, 18-21 February, SPE paper 37233 (1997)
Dixit A.B., Buckley J.S., McDougall S.R., Sorbie K.S.: Core wettability: Should IAH Equal IUSBM? Paper presented at the International Symposium of the SCA, the Hague, the September (1998)
Dixit A.B., McDougall S.R., Sorbie K.S. and Buckley J.S. (1999). Pore-Scale modelling of wettability effects and their influence on oil recovery. SPE Reservoir Eval. Eng. 2(1): 25–36
Dixit A.B., Buckley J.S., McDougall S.R. and Sorbie K.S. (2000). Empirical measure of wettability in porous media and the relationship between them derived from pore-scale modeling. Transport Porous Med. 40: 27–54
Donaldson, E.C., Thomas, R.D., Lorenz, P.B.: Wettability determination and its effect on recovery efficiency. SPE J. March, 13–20 (1969)
Heiba, A.A., Davis, H.T., Scriven, L.E.: Effect of Wettability on Two-Phase Relative Permeabilities and Capillary Pressures, Paper presented at the 58th Annual Technical Conference and Exhibition held in San Francisco, CA, October 5-8, SPE paper 12172 (1983)
Jackson M.D., Valvatne P.H. and Blunt M.J. (2003). Predictions of wettability variation and its impact on flow using pore- to reservoir-scale simulations. J. Petrol. Sci. Eng. 39: 231–246
Kovscek A.R., Wong H. and Radke C.J. (1993). A Pore-Level Scenario for the Development of Intermediate wettability in Oil Reservoirs. AlChE J. 39(6): 1072–1085
Land, C.S.: Calculation of Imbibition relative permeability for two-and three-phase flow from rock properties. SPE J. June, 149–156 (1968)
Lenormand R., Zarcone C. and Sarr A. (1983). Mechanisms of the displacement of one fluid by another in a network of capillary ducts. J. Fluid Mech. 135: 337–353
Lenormand, R., Zarcone, C.: Role of roughness and edges during imbibition in square capillaries, Presented at the SPE Annual Technical Conference and Exhibition, 16-19 September, Houston, Texas, SPE paper 13264 (1984)
Ma S., Mason G. and Morrow N.R. (1996). Effect of contact angle on drainage and imbibition in regular polygonal tubes. Colloid. Surf. A: Physicochem Eng. Aspect. 117: 273–291
Mason G. and Morrow N.R. (1984). Meniscus Curvatures in Capillaries of Uniform Cross-section. J. Chem. Soc. Faraday Trans. 1 1(80): 2375–2393
McDougall S.R. and Sorbie K.S. (1995). The impact of wettability on water flooding: Pore-scale simulation. SPE Reservoir Eng. 10(3): 208–213
Mohanty, K.K., Salter, S.J.: Multiphase Flow in Porous Media: III. Oil Mobilization, Transverse Dispersion, and Wettability, Paper presented at the 58th Annual Technical Conference and Exhibition held in San Francisco, CA, October 5-8, SPE paper 12127 (1983)
Morrow, N.R., McCaffery, F.G.: Displacement Studies in Uniformly Wetted Porous Media, of Chemical Ind. International symposium on wetting, Loughborough, England, 21–29 September (1976)
Øren, P.E., Bakke, S., Arntzen, O.J.: Extending predictive capabilities to network models. SPE J. December, 324–336 (1998)
Øren P.E. and Bakke S. (2002). Process based reconstruction of sandstones and prediction of transport properties. Transport Porous Med. 46: 311–343
Øren P.E. and Bakke S (2003). Reconstruction of Berea sandstone and pore-scale modelling of wettability effects. J. Petrol. Sci. Eng. 39: 177–199
Skauge, A., Ottesen, B.: A Summary of Experimentally derived Relative Permeability and Residual Saturation on North Sea Reservoir Cores, Paper presented at the International Symposium of the SCA, Monterey, CA, September (2002)
Skauge, A., Ottesen, B., Vik, B.: Variation of Special Core Analysis Properties for Intermediate Wet Sandstone Material, Paper presented at the International Symposium of the SCA, Pau, France, September (2003)
Skauge, A., Spildo, K., Høiland, L., Vik, B.: Theoretical and experimental evidence of different wettability classes. J. Petrol. Sci. Eng. in press (2006)
Valvatne, P.H., Blunt, M.J.: Predictive Pore-Scale Network Modeling, Paper presented at the SPE Annual Technical Conference and Exhibition held in Denver, Colorado, USA, 5–8 October, SPE paper 84550 (2003)
Valvatne, P.H., Jing, X.D., Smits, R.M.M.: (2004), Modeling Pore Geometric and Wettability Trends of Multiphase flow in Porous Media, Paper Presented at the International Symposium of the Society of Core Analysts held in Abu Dhabi, UAE, 5–9 October
Valvatne, P.H.: Predictive Pore-Scale Network Modeling, PhD thesis, Imperial college, London, England (2004)
Valvatne, P.H., Blunt, M.J.: Predictive pore-scale modeling of two-phase flow in mixed wet media. Water Resour. Res. 40, W07406, doi:10.1029/2003WR002627 (2004)
Wilkinson D. and Willemsen J.F. (1983). Invasion percolation: a new form of percolation theory. J. Phys., A: Math. Gen 16: 3365–3376
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Høiland, L.K., Spildo, K. & Skauge, A. Fluid flow properties for different classes of intermediate wettability as studied by network modelling. Transp Porous Med 70, 127–146 (2007). https://doi.org/10.1007/s11242-006-9088-x
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DOI: https://doi.org/10.1007/s11242-006-9088-x