Advanced

Fracture mapping using seismic amplitude variation with offset and azimuth analysis at the Weyburn CO2 storage site

Duxbury, Alexander; White, Donald; Samson, Claire; Hall, Stephen LU ; Wookey, James and Kendall, J-Michael (2012) In Geophysics 77(6). p.17-28
Abstract
Cap rock integrity is an essential characteristic of any reservoir to be used for long-term CO 2 storage. Seismic AVOA (amplitude variation with offset and azimuth) techniques have been applied to map HTI anisotropy near the cap rock of the Weyburn field in southeast Saskatchewan, Canada, with the purpose of identifying potential fracture zones that may compromise seal integrity. This analysis, supported by modeling, observes the top of the regional seal (Watrous Formation) to have low levels of HTI anisotropy, whereas the reservoir cap rock (composite Midale Evaporite and Ratcliffe Beds) contains isolated areas of high intensity anisotropy, which may be fracture-related. Properties of the fracture fill and hydraulic conductivity within... (More)
Cap rock integrity is an essential characteristic of any reservoir to be used for long-term CO 2 storage. Seismic AVOA (amplitude variation with offset and azimuth) techniques have been applied to map HTI anisotropy near the cap rock of the Weyburn field in southeast Saskatchewan, Canada, with the purpose of identifying potential fracture zones that may compromise seal integrity. This analysis, supported by modeling, observes the top of the regional seal (Watrous Formation) to have low levels of HTI anisotropy, whereas the reservoir cap rock (composite Midale Evaporite and Ratcliffe Beds) contains isolated areas of high intensity anisotropy, which may be fracture-related. Properties of the fracture fill and hydraulic conductivity within the inferred fracture zones are not constrained using this technique. The predominant orientations of the observed anisotropy are parallel and normal to the direction of maximum horizontal stress (northeast–southwest) and agree closely with previous fracture studies on core samples from the reservoir. Anisotropy anomalies are observed to correlate spatially with salt dissolution structures in the cap rock and overlying horizons as interpreted from 3D seismic cross sections. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Geophysics
volume
77
issue
6
pages
17 - 28
publisher
Soc Exploration Geophysicists
external identifiers
  • wos:000312824300005
  • scopus:84870170477
ISSN
0016-8033
DOI
10.1190/geo2011-0075.1
language
English
LU publication?
yes
id
bd4ffa43-fc61-41b0-b111-3a5e5c4ace4c (old id 3164452)
date added to LUP
2012-11-13 12:22:12
date last changed
2017-11-12 04:08:49
@article{bd4ffa43-fc61-41b0-b111-3a5e5c4ace4c,
  abstract     = {Cap rock integrity is an essential characteristic of any reservoir to be used for long-term CO 2 storage. Seismic AVOA (amplitude variation with offset and azimuth) techniques have been applied to map HTI anisotropy near the cap rock of the Weyburn field in southeast Saskatchewan, Canada, with the purpose of identifying potential fracture zones that may compromise seal integrity. This analysis, supported by modeling, observes the top of the regional seal (Watrous Formation) to have low levels of HTI anisotropy, whereas the reservoir cap rock (composite Midale Evaporite and Ratcliffe Beds) contains isolated areas of high intensity anisotropy, which may be fracture-related. Properties of the fracture fill and hydraulic conductivity within the inferred fracture zones are not constrained using this technique. The predominant orientations of the observed anisotropy are parallel and normal to the direction of maximum horizontal stress (northeast–southwest) and agree closely with previous fracture studies on core samples from the reservoir. Anisotropy anomalies are observed to correlate spatially with salt dissolution structures in the cap rock and overlying horizons as interpreted from 3D seismic cross sections.},
  author       = {Duxbury, Alexander and White, Donald and Samson, Claire and Hall, Stephen and Wookey, James and Kendall, J-Michael},
  issn         = {0016-8033},
  language     = {eng},
  number       = {6},
  pages        = {17--28},
  publisher    = {Soc Exploration Geophysicists},
  series       = {Geophysics},
  title        = {Fracture mapping using seismic amplitude variation with offset and azimuth analysis at the Weyburn CO2 storage site},
  url          = {http://dx.doi.org/10.1190/geo2011-0075.1},
  volume       = {77},
  year         = {2012},
}