Flow-dependence of matrix diffusion in highly heterogeneous rock fractures
2013 (English)In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 49, no 11, 7587-7597 p.Article in journal (Refereed) Published
Diffusive mass transfer in rock fractures is strongly affected by fluid flow in addition to material properties. The flow-dependence of matrix diffusion is quantified by a random variable ("transport resistance'') denoted as beta [T/L] and computed from the flow field by following advection trajectories. The numerical methodology for simulating fluid flow is mesh-free, using Fup basis functions. A generic statistical model is used for the transmissivity field, featuring three correlation structures: (i) highly connected non-multiGaussian; (ii) poorly connected (or disconnected) non-multi-Gaussian; and (iii) multi-Gaussian. The moments of beta are shown to be linear with distance, irrespective of the structure, after approximately 10 integral scales of ln T. Percentiles of beta are found to be linear with the mean beta when considering all three structures. Taking advantage of this property, a potentially useful relationship is presented between beta percentiles and the fracture mean water residence time that integrates all structures with high variability; it can be used in discrete fracture network simulations where T statistical data on individual fractures are not available.
Place, publisher, year, edition, pages
2013. Vol. 49, no 11, 7587-7597 p.
rock fractures, diffusive mass transfer, heterogeneity structure, transport, retention, attenuation
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:kth:diva-140175DOI: 10.1002/2013WR014213ISI: 000328683800031ScopusID: 2-s2.0-84887863971OAI: oai:DiVA.org:kth-140175DiVA: diva2:689055
QC 201401202014-01-202014-01-172014-01-20Bibliographically approved