Influence of open and sealed fractures on fluid flow and water saturation in sandstone cores using Magnetic Resonance Imaging

Baraka-Lokmane, S., Teutsch, G. and Main, I.G. (2001) Influence of open and sealed fractures on fluid flow and water saturation in sandstone cores using Magnetic Resonance Imaging Geophysical Journal International, 147 (2). pp. 263-271. ISSN 0956-540X

Full text not available from this repository.

Abstract

We use Magnetic Resonance Imaging (MRI) to image the imbibition of water by capillary action in a right-cylindrical sample of a porous sedimentary rock with low iron content. In the method some 55 repeat images are taken over a period of approximately two hours, covering five vertical sections. The evolution of the water flood front and the degree of water saturation can be observed by examining snapshots of proton density. The results clearly show (a) the development of a rising wetting front in the rock matrix (b) preferential flow along open fractures observed on the core surface, and (c) reduced flow associated with sealed fractures. The inferred location, orientation and connectivity of conducting and sealing fractures are confirmed by impregnating the sample after the test with an appropriate low-viscosity setting resin and taking serial thin sections in destructive mode. The results validate the utility of MRI as a non-destructive analytical tool for visualizing the distribution of water inside fractured porous media with low iron content. The technique identifies paths of high and low permeability in the sample, and quantifies the fracture location, orientation, and connectivity in sedimentary rocks. Preferential fluid flow in open fractures during capillary imbibition implies that the fractures are more water-wet than the clasts within the matrix. This may be due to due to differences in the age, morphology and mineral structure on the surface of the pores and the fractures.

Item Type:Journal article
Uncontrolled Keywords:fracture geometry; MRI; water saturation
Subjects:F000 Physical Sciences > F800 Physical Geography and Environmental Sciences > F840 Physical Geography
F000 Physical Sciences > F600 Geology
DOI (a stable link to the resource):10.1046/j.0956-540x.2001.01519.x
Faculties:Faculty of Science and Engineering > School of Environment and Technology > Applied Geosciences
Faculty of Science and Engineering > School of Environment and Technology
ID Code:2154
Deposited By:editor environment
Deposited On:21 Jan 2008
Last Modified:09 May 2012 09:16

Repository Staff Only: item control page