Roles of chemical and mechanical processes on the evolution of fracture permeability in carbonates

T. P. McGuire, D. Elsworth, Z. Karcz

Research output: Contribution to conferencePaper

Abstract

We explore how fracture permeability in confined carbonates evolves due to flow of reactive fluids. Core plugs of the Capitan Massive Limestone are saw-cut to form a consistent axial fracture that is subsequently roughened to simulate a natural fracture with controlled topography. Either distilled water or 0.176 M NH4Cl solutions are circulated while initial fracture roughness, influent fluid pH, and confining stresses are controlled. Throughout the experiment we measure the fluid flow rate and chemical composition of the effluent fluid. The cubic law is used to infer the retreat or advance rate of the fracture walls from the evolution of permeability. By taking measurements in regimes of both increasing and decreasing permeability we quantitatively constrain the transition between fracture-gaping and fracture-closing modes of behavior. We parameterize this transition using the ratio of mechanically- to chemically-controlled dissolved mass fluxes and compare it to the effective hydraulic aperture velocity. The transition value of unity for the mass flux ratio logically coincides with a predicted net effective hydraulic aperture velocity that asymptotes to zero. These results offer a first opportunity of constraining the transition between stress-dominated and dissolution-dominated mechanisms of permeability evolution for stress-sensitive fractures.

Original languageEnglish (US)
StatePublished - Dec 6 2011
Event45th US Rock Mechanics / Geomechanics Symposium - San Francisco, CA, United States
Duration: Jun 26 2011Jun 29 2011

Other

Other45th US Rock Mechanics / Geomechanics Symposium
CountryUnited States
CitySan Francisco, CA
Period6/26/116/29/11

Fingerprint

Carbonates
carbonates
permeability
carbonate
hydraulics
Fluids
fluid
fluids
Mass transfer
apertures
Hydraulics
advance rate
asymptotes
chemical
Calcium Carbonate
effluents
limestone
closing
plugs
confining

All Science Journal Classification (ASJC) codes

  • Geochemistry and Petrology
  • Geophysics

Cite this

McGuire, T. P., Elsworth, D., & Karcz, Z. (2011). Roles of chemical and mechanical processes on the evolution of fracture permeability in carbonates. Paper presented at 45th US Rock Mechanics / Geomechanics Symposium, San Francisco, CA, United States.
McGuire, T. P. ; Elsworth, D. ; Karcz, Z. / Roles of chemical and mechanical processes on the evolution of fracture permeability in carbonates. Paper presented at 45th US Rock Mechanics / Geomechanics Symposium, San Francisco, CA, United States.
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McGuire, TP, Elsworth, D & Karcz, Z 2011, 'Roles of chemical and mechanical processes on the evolution of fracture permeability in carbonates' Paper presented at 45th US Rock Mechanics / Geomechanics Symposium, San Francisco, CA, United States, 6/26/11 - 6/29/11, .

Roles of chemical and mechanical processes on the evolution of fracture permeability in carbonates. / McGuire, T. P.; Elsworth, D.; Karcz, Z.

2011. Paper presented at 45th US Rock Mechanics / Geomechanics Symposium, San Francisco, CA, United States.

Research output: Contribution to conferencePaper

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McGuire TP, Elsworth D, Karcz Z. Roles of chemical and mechanical processes on the evolution of fracture permeability in carbonates. 2011. Paper presented at 45th US Rock Mechanics / Geomechanics Symposium, San Francisco, CA, United States.