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Capillary entrapment caused by small-scale wettability heterogeneities

Journal Article · · SPE Reservoir Engineering
DOI:https://doi.org/10.2118/30782-PA· OSTI ID:227838
Small-scale heterogeneities are abundant in oil reservoirs. It is well known that these heterogeneities can reduce the displacement efficiency of immiscible flooding because of capillary entrapment of oil. A typical heterogeneous facies is the laminated crossbed set with alternating high- and low-permeability laminae. Apart from this heterogeneity in grain size, the wettability of the laminae can also differ. The laminae can contain different minerals with different wetting characteristics, and wettability can be affected by adsorption of hydrocarbons to the grain surface. In this paper the authors focus on the effects of wettability on the entrapment. They describe a procedure that allows the reader to quantify the trapped oil saturation depending on absolute permeability, relative permeability, and capillary pressure curves of the foreset laminae, on the basis of a simplified crossbed geometry. The example calculations show the sensitivity of various parameters with respect to the magnitude of trapping.
Sponsoring Organization:
USDOE
OSTI ID:
227838
Journal Information:
SPE Reservoir Engineering, Journal Name: SPE Reservoir Engineering Journal Issue: 2 Vol. 11; ISSN 0885-9248; ISSN SREEEF
Country of Publication:
United States
Language:
English