Laboratory investigation of capillary trapping under mixed‐wet conditions. Issue 7 (29th July 2013)

• Record Type: Journal Article
• Authors: Tanino, Y.; Blunt, M. J.
• Is Part Of: Water resources research. Volume 49:Issue 7(2013:Jul.)
• Page Start: 4311
• Page End: 4319
• Publication Date: 2013-07-29
• Subjects: Hydrology -- Periodicals; 333.91
• DOI: 10.1002/wrcr.20344
• Languages: English
• ISSNs: 0043-1397

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>[1] Remaining oil saturation established by waterflooding was measured in Indiana limestone in its original, water‐wet state and under mixed‐wet conditions established by adding organic acid to the oil phase. The porous plate technique was used to establish initial oil saturations ranging from <italic>S</italic>_nwi = 0.23 to 0.93 under capillary‐dominated conditions. For water‐wet conditions, the residual oil saturation increased linearly with its initial saturation. In contrast, the remaining oil saturation under mixed‐wet conditions, <italic>S</italic>_nw, displayed three distinct regimes. First, <italic>S</italic>_nw increased with its initial saturation up to <italic>S</italic>_nwi = 0.58. Next, <italic>S</italic>_nw decreased from <italic>S</italic>_nwi = 0.58 to 0.76. Finally, <italic>S</italic>_nw increased again as <italic>S</italic>_nwi approached one. The nonmonotonic dependence of <italic>S</italic>_nw on <italic>S</italic>_nwi at <italic>S</italic>_nwi &gt; 0.5 is well described by a concave‐up quadratic function, and may be a salient feature of mixed‐wet rocks.</p> </abstract>