Ensemble relative permeability in naturally fractured rocks: the role of wettability
Research output: Contribution to conference › Presentation › Research › peer-review
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- University of Melbourne
Abstract
Where fractures provide the permeability and the rock matrix the storage for oil and gas, fracture-matrix transfer has a decisive impact on recovery and capillary-driven transfer. However, while most modeling assumes constant (often zero) fracture capillary pressure, in actuality, fracture aperture varies among and within individual fractures, so will capillary pressure. Here we contrast and compare relative permeability curves derived from simple and more realistic fracture capillary pressure treatments applied in discrete fracture and matrix simulations (DFM) of pervasively fractured layered rock mapped in meter- to kilometer-scale outcrops. Fracture aperture is obtained by mechanical modeling. Imbibition simulations are performed with the Finite Element-Centered Finite Volume Method (FECFVM). Resulting fracture-matrix ensemble relative permeability curves highlight the importance of wettability: ultimate recovery is 2-3 times higher in the water-wet than the oil-wet case. With increasing wetting angle, counter-current-imbibition (CCI) rate decreases gradually because small fractures that contribute to the most of the fracture-matrix transfer area have small fracture-matrix capillary pressure differences.
Details
Original language | English |
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Publication status | Published - 14 Sept 2017 |
Event | SIAM Conference on Mathematical and Computational Issues in the Geosciences - Erlangen, Germany Duration: 11 Sept 2017 → 14 Sept 2017 http://www.siam-gs17.de/ |
Conference
Conference | SIAM Conference on Mathematical and Computational Issues in the Geosciences |
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Country/Territory | Germany |
City | Erlangen |
Period | 11/09/17 → 14/09/17 |
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