Potential seal bypass and caprock storage produced by deformation-band-to-opening-mode-fracture transition at the reservoir/caprock interface

Journal Article · Sat Jun 18 00:00:00 EDT 2016 · Geofluids

DOI:https://doi.org/10.1111/gfl.12177· OSTI ID:1416301

Raduha, S. ^[1]; Butler, D. ^[1]; Mozley, P. S. ^[1]; Person, M. ^[1]; Evans, J. ^[2]; Heath, J. E. ^[3]; Dewers, T. A. ^[3]; Stauffer, P. H. ^[4]; Gable, C. W. ^[4]; Kelkar, S. ^[4]

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1. New Mexico Tech., Socorro, NM (United States). Dept. of Earth and Environmental Science
2. Utah State Univ., Logan, UT (United States). Dept. of Geology
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Here, we examined the potential impact on CO₂ transport of zones of deformation bands in reservoir rock that transition to opening-mode fractures within overlying caprock. Sedimentological and petrophysical measurements were collected along an approximately 5 m × 5 m outcrop of the Slick Rock and Earthy Members of the Entrada Sandstone on the eastern flank of the San Rafael Swell, Utah, USA. Measured deformation band permeability (2 mD) within the reservoir facies is about three orders of magnitude lower than the host sandstone. Average permeability of the caprock facies (0.0005 mD) is about seven orders of magnitude lower than the host sandstone. Aperture-based permeability estimates of the opening-mode caprock fractures are high (3.3 × 10⁷ mD). High-resolution CO₂–H₂O transport models incorporate these permeability data at the millimeter scale. We then varied fault properties at the reservoir/caprock interface between open fractures and deformation bands as part of a sensitivity study. Numerical modeling results suggest that zones of deformation bands within the reservoir strongly compartmentalize reservoir pressures largely blocking lateral, cross-fault flow of supercritical CO₂. Significant vertical CO₂ transport into the caprock occurred in some scenarios along opening-mode fractures. The magnitude of this vertical CO₂ transport depends on the small-scale geometry of the contact between the opening-mode fracture and the zone of deformation bands, as well as the degree to which fractures penetrate caprock. Finally, the presence of relatively permeable units within the caprock allows storage of significant volumes of CO₂, particularly when the fracture network does not extend all the way through the caprock.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Center for Frontiers of Subsurface Energy Security (CFSES); Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE; USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC04-94AL85000; AC52-06NA25396; FE0004844; SC0001114
• OSTI ID: 1416301
• Alternate ID(s): OSTI ID: 1400767; OSTI ID: 1497662
• Report Number(s): LA-UR--17-27584; SAND--2017-1967J
• Journal Information: Geofluids, Journal Name: Geofluids Journal Issue: 4 Vol. 16; ISSN 1468-8115
• Publisher: Hindawi
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
caprock
carbon storage
deformation bands
fractures
multiphase flow
reservoir rock
seal bypass