Study of Two Phase Fluid Flow in Water Wet Reservoir Rocks by Using X-Ray In situ Saturation Monitoring

Document Type : Research Paper

Authors

Research Institute of Petroleum Industry (RIPI), Exploration and Production Research Center

Abstract

Displacement of oil and water in porous media of reservoir rocks is described by relative                      permeability curves, which are important input data for reservoir performance simulation and drive mechanism studies. Many core studies, such as multiphase relative permeability, capillary pressure and saturation exponent determination, depend on the volume fractions of multiphase fluids present in the studied rock samples. X-ray scanners are increasingly used for measurement of fluids saturation in the core samples during core studies, mainly due to expanding need of modeling and measuring reservoir condition fluid flow behavior and its being safer issues than other radioactive sources like gamma ray. Incorporating X-Ray in situ saturation measurements into the relative permeability, capillary pressure and intrinsic wettability characterization of reservoir rocks may improve reservoir management and productivity prediction. This paper describes two phase immiscible fluid flow behavior of oil displaced by water through water wet porous media interpreted by X-ray data utility, according to saturation profile shapes incorporated by history matching of oil production and differential pressure history in low oil to water viscosity ratio fluid flow. In situ saturation profiles have been obtained with 1% saturation accuracy. The in situ saturation profiles confirm wettability character of reservoir rock samples and are an indication                     of the fact that initial water saturation and non-wetting oil phase values are controlled by reservoir rock wettability characteristics. The immovable water saturation increases because of oil snap-off and when light oil enters a water wet porous media, even increasing the oil injection rate cannot overcome van der Waals forces throughout water molecules. The saturation profiles have been shaped rather flat after water breakthrough. These profiles attribute to the recovery of the bulk of oil before breakthrough in low viscosity ratio displacement through water wet rocks. Besides, overlapping of various after bump saturation profiles indicates that there is no significant difference between remaining oil saturation and residual oil saturation in water wet reservoir rocks.

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Reference
 
[1] Maloney, D.R., Wegener, D.C. , Zornes, D.R.,                Significance of Absorption Coefficients When Determining In-Situ Core Saturations by Linear X-ray Scans SCA 2013. Presented at 2000 SCA conference.
[2] Maloney, D.R., X-ray imaging technique simplifies and improves reservoir-condition unsteady-state relative permeability measurements. SCA 0211. Presented at 2002 SCA conference.
[3] Al-Shuraiqi, H.S., Grattoni, C.A., Muggeridge, A.H., Numerical and experimental investigation into the                 effects of viscosity and injection rate on relative permeability and oil recovery. SCA 2005-40, 2005.
[4] Guo-Qing, T., Kovscek, A.R., High-resolution                    imaging of high mobility ratio, immiscible displacements. SCA 2005-16, 2005.
[5] Pavone, D., Observation and correlations for immiscible viscous-fingering experiments. SPE Res. Eng., pp.187-192., May 1992.
[6] Donaldson, E.C., Lorenz, P., Thomas, R.D., The              effects of viscosity and wettability on oil and water relative permeabilities. SPE 1562 41st Annual SPE Fall Meeting, Dallas, 1942.
[7] Geffen, T., Owens, W., Parrish, D., Morse,R., Experimental investigation of factors affecting laboratory                     relative permeability measurements. Trans., AIME, Vol.192, pp.99-110, 1951.
[8] Morgan, J.T., Gordon, D.T., Influence of pore geometry on water-oil relative permeabilities. JPT. pp. 1199-1208, Oct.1970.
[9] Mungan, N., Relative permeability measurements using reservoir fluids. SPEJ. pp. 398-402, Oct.1972.
[10] McCaffery, F.G., Bennion, D.W., The effect of            wettability on two-phase relative permeabilities. Journal of Canadian Petroleum Technology, Vol. 13, No.4. pp. 42-53, 1974.
[11] Wendel, D.J., Anderson, W.G., Meyers, J.D.                 Restored-state core analysis for the Hutton reservoir. SPE Annual Technical Conference and Exhibition, Las              Vegas, pp.22-25, 1985.
[12] Anderson, W.G., Wettability literature survey – Part 5: The effects of wettability on relative permeability. JPT.  pp. 1453-1468,  Nov.1987.
[13] Stalheim, S.O., Eidesmo, T., Rueslatten, H., Influence of wettability on water saturation modeling. Journal of Pet.Sc. and Eng. Vol. 24, pp.243-253, 1999.
[14] Craig, F.F., The reservoir engineering aspects of water-flooding. Monograph series, SPE, Richardson, TX 3. 1971.
[15] Anderson, W.G., Wettability literature survey - Part 1: Rock/oil/brine interactions and the effects of core handling on wettability. JPT. pp.1125-1149, Oct. 1986. 
[16] Naylor, P., Puckett, D., In-situ saturation distributions, the key to understanding core analysis. SCA 9405. Presented at 1994 SCA conference.
[17] Mattax, C.C., Kyte, J.R., Ever see a water-flood? Oil & Gas J. Vol.59, No.42,  pp.115-128, 1961
[18] Morris, E.E., Wieland, D.R., A microscopic study of the effect of variable wettability conditions on                              immiscible fluid displacement. SPE Annual Meeting, New Orleans, pp. 6-9, 1963.
[19] Raza, S.G., Treiber, J.E., Archer, D.L., Wettability of reservoir rocks and its evaluation. Prod. Monthly.32, no.4. 2-7, 1968.
[20] Donaldson, E.C., Thomas, R.D., Microscopic              observations of oil displacement in water-wet and oil-wet systems. SPE Annual Meeting, New Orleans, pp. 3-6, 1971.
[21] Wang, J.X, Buckley, J.S., 1999. Wettability and rate effects on end-point relative permeability to water. SCA 9937. Presented at 1999 SCA conference.
[22] Coles, M.E. , Spanne, P., Muegge, E.L., and Jones, K. W., Computed Microtomography of Reservoir Core Samples, SCA-9401, Presented at 1994 SCA conference.
[23] Bakul C.S., William E.B., Louis M.C., CT Imaging Techniques for Two-Phase and Three-Phase In-Situ Saturation Measurements, SUPRI TR 107 Report, June1997, Stanford University
[24] Jones, S.C., Roszelle, W.O., Graphical techniques for determining relative permeability from displacement experiments. JPT. pp.807-817, May 1978.
[25] Kamath, J., Meyer, R.F., Nakagawa, M., Understanding water-flood residual oil saturation of four carbonate rock types. New Orleans, Louisiana, SPE 71505, 2001.