Wettability effects on oil recovery mechanisms in fractured chalk
Abstract
This thesis is a part of the ongoing project, “Oil recovery from fractured chalk reservoirs”, which is a collaboration between the Reservoir Physics Group at the University of Bergen and ConocoPhillips Research Center in Bartlesville, Oklahoma. The project was initiated in 1990 and for the last 15 years about 30 Master and PhD candidates have graduated and, mainly employed by the oil industry. Dedicated candidates combined with professional guidance and stable funding has been a key to the success of this long term research project. Early work in this project report experiments on large chalk blocks subjected to water floods. The dynamics of the water front propagation during water floods were monitored by nuclear tracer imaging for homogeneous whole blocks and when fractured. The impact of the fractures on the water flood could then be investigated. Emphasis was on the effect of wettability condition on the recovery mechanism. In addition to the saturation monitoring system, attempts to measure the pressure difference across different fractures in the block were made with varying degree of success. Based on the findings of the earlier work, emphasis for further research as a part of this thesis work was chosen: 1. Improve the aging technique to obtain reproducible, uniform and relevant wettabilities 2. Improve imaging in order to study the details on fluid transfer across open fractures at different wettability conditions.
Has parts
Paper I: Journal of Petroleium Science & Engineering 33(1), Graue, A.; Aspenes, E.; Bognø, T.; Moe, R. W. and Ramsdal, J., Alteration of Wettability and Wettability Heterogeneity, pp. 3-17(15). Copyright 2002 Elsevier. http://dx.doi.org/10.1016/S0920-4105(01)00171-1Paper II: Journal of Petroleium Science & Engineering 39, Aspenes. E.; Graue, A.; Ramsdal, J., In-Situ Wettability Distribution and Wetting Stability in Outcrop Chalk Aged in Crude Oil, pp. 337-350. Copyright 2003 Elsevier. http://dx.doi.org/10.1016/S0920-4105(03)00073-1
Paper III: Graue, A.; Aspenes, E.; Moe, R. W.; Baldwin, B. A.; Moradi, A.; Stevens, J.; Tobola, D. P., (2001), MRI Tomography of Saturation Development in Fractures During Waterfloods at Various Wettability Conditions, SPE 71506, Proc.: 2001 SPEATCE, New Orleans, Louisiana, USA, Oct. 1-3, 2001. Appeared as synopsis in JPT, January 2002, (52-53). Invited for publication in SPEJ. Copyright Society of Petroleum Engineers. Fulltext not available due to publisher restrictions.
Paper IV: Aspenes, E.; Graue, A.; Baldwin, B. A.; Moradi, A.; Stevens, J.; Tobola, D.P., Fluid Flow in Fractures Visualized by MRI During Waterfloods at Various Wettability Conditions - Emphasis on Fracture Width and Flow Rate, SPE 77338, Proc.: 2002 SPEATCE, San Antonio, TX, USA, Sept. 29- Oct. 3, 2002. Copyright Society of Petroleum Engineers. Submitted to Journal of Petroleum Science and Engineering. Published by Elsevier. Fulltext not available due to publisher restrictions.
Paper V: Graue, A.; Baldwin, B. A.; Aspenes, E.; Stevens, J.; Tobola, D. P.; Zornes, D. R., Complementary Imaging Techniques Applying NTI and MRI Determined Wettability Effects on Oil Recovery Mechanisms in Fractured Reservoirs, Reviewed Proc.: "2003 International Symposium of the Society of Core Analysts", Pau, France, Sept. 21-24, 2003. Copyright 2003 Society of Core Analysts.
Paper VI: Aspenes, E.; Ersland, G.; Graue, A.; Stevens, J.; Baldwin, B. A., Wetting Phase Bridges Establish Capillary Continuity Across Open Fractures And Increase Oil Recovery In Mixed-Wet Fractured Chalk. Preprint. Submitted to Transport in Porous Media. Published by Springer Verlag.