Dataset Information

Subsecond pore-scale displacement processes and relaxation dynamics in multiphase flow.

ABSTRACT: With recent advances at X-ray microcomputed tomography (?CT) synchrotron beam lines, it is now possible to study pore-scale flow in porous rock under dynamic flow conditions. The collection of four-dimensional data allows for the direct 3-D visualization of fluid-fluid displacement in porous rock as a function of time. However, even state-of-the-art fast-?CT scans require between one and a few seconds to complete and the much faster fluid movement occurring during that time interval is manifested as imaging artifacts in the reconstructed 3-D volume. We present an approach to analyze the 2-D radiograph data collected during fast-?CT to study the pore-scale displacement dynamics on the time scale of 40 ms which is near the intrinsic time scale of individual Haines jumps. We present a methodology to identify the time intervals at which pore-scale displacement events in the observed field of view occur and hence, how reconstruction intervals can be chosen to avoid fluid-movement-induced reconstruction artifacts. We further quantify the size, order, frequency, and location of fluid-fluid displacement at the millisecond time scale. We observe that after a displacement event, the pore-scale fluid distribution relaxes to (quasi-) equilibrium in cascades of pore-scale fluid rearrangements with an average relaxation time for the whole cascade between 0.5 and 2.0 s. These findings help to identify the flow regimes and intrinsic time and length scales relevant to fractional flow. While the focus of the work is in the context of multiphase flow, the approach could be applied to many different ?CT applications where morphological changes occur at a time scale less than that required for collecting a ?CT scan.

SUBMITTER: Armstrong RT

PROVIDER: S-EPMC4328147 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature

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Subsecond pore-scale displacement processes and relaxation dynamics in multiphase flow.

Armstrong Ryan T RT Ott Holger H Georgiadis Apostolos A Rücker Maja M Schwing Alex A Berg Steffen S

Water resources research 20141201 12

With recent advances at X-ray microcomputed tomography (μCT) synchrotron beam lines, it is now possible to study pore-scale flow in porous rock under dynamic flow conditions. The collection of four-dimensional data allows for the direct 3-D visualization of fluid-fluid displacement in porous rock as a function of time. However, even state-of-the-art fast-μCT scans require between one and a few seconds to complete and the much faster fluid movement occurring during that time interval is manifeste ...[more]

PMID: 25745271

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Dataset Information

Subsecond pore-scale displacement processes and relaxation dynamics in multiphase flow.

Publications

Subsecond pore-scale displacement processes and relaxation dynamics in multiphase flow.

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