Imaging of the Shallow Alpine Fault Zone (New Zealand) Using 2D and Pseudo 3D Seismic Reflection Data

2010 ◽  
Author(s):  
A.E. Kaiser ◽  
H. Horstmeyer ◽  
A.G. Green ◽  
F. Campbell ◽  
R.M. Langridge ◽  
...  
Keyword(s):  
New Zealand ◽  
Fault Zone ◽  
Seismic Reflection ◽  
3D Seismic ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Alpine Fault

Detailed images of the shallow Alpine Fault Zone, New Zealand, determined from narrow-azimuth 3D seismic reflection data

Geophysics ◽  
2011 ◽  
Vol 76 (1) ◽  
pp. B19-B32 ◽  
Author(s):  
A. E. Kaiser ◽  
H. Horstmeyer ◽  
A. G. Green ◽  
F. M. Campbell ◽  
R. M. Langridge ◽  
...  
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Fault Zone ◽  
Seismic Reflection ◽  
3D Seismic ◽  
3D Images ◽  
Alpine Fault ◽  
3D Acquisition ◽  
2D Data ◽  
Basement Surface

Previous high-resolution seismic reflection investigations of active faults have been based on 2D profiles. Unfortunately, 2D data may be contaminated by out-of-the-plane reflections and diffractions that may be difficult to identify and eliminate. Although full 3D seismic reflection methods allow out-of-the-plane events to be recognized and provide superior resolution to 2D methods, they are only rarely applied in environmental and engineering studies because of high costs. A narrow-azimuth 3D acquisition and processing strategy is introduced to produce a high-resolution seismic reflection volume centered on the Alpine Fault Zone (New Zealand). The shallow 3D images reveal late Quaternary deformation structures associated with this major transpressional plate-boundary fault. The relatively inexpensive narrow-azimuth 3D acquisition pattern consisting of inline source and receiver lines was easily implemented in the field to provide 2- by [Formula: see text] CMP coverage over an approximately 500- by [Formula: see text] area.The narrow-azimuth acquisition strategy was well suited for resolving complex structures within the fault zone. Challenges in processing the data were amplified by the effects of strong velocity heterogeneity in the near surface and the presence of complex dipping, diffracted, and truncated events. A carefully tailored processing scheme including surface-consistent deconvolution, refraction static corrections, noise reduction, dip moveout (DMO) corrections, and 3D depth migration greatly improved the appearance of the final stacks. The 3D images reveal strong reflections from the faulted and folded late Pleistocene erosional basement surface. A steeply dipping planar main (dominant) fault strand can be inferred from the geometry and truncations of the overlying postglacial sediments. The 3D images reveal that the average apparent vertical displacement [Formula: see text] of the basement surface across the dominant fault strand at this location is somewhat less than that estimated from a pilot 2D seismic reflection profile, suggesting that the provisional dip-slip rate based on the 2D data is a maximum.

Investigating fault continuity associated with geologic carbon storage planning in the Illinois Basin

2014 ◽  
Vol 2 (1) ◽  
pp. SA151-SA162 ◽  
Author(s):  
John H. McBride ◽  
R. William Keach ◽  
Eugene E. Wolfe ◽  
Hannes E. Leetaru ◽  
Clayton K. Chandler ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Seismic Reflection ◽  
Oil Field ◽  
Illinois Basin ◽  
Storage Site ◽  
3D Seismic ◽  
Seismic Attribute ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Attribute Analyses

Because the confinement of [Formula: see text] in a storage reservoir depends on a stratigraphically continuous set of seals to isolate the fluid in the reservoir, the detection of structural anomalies is critical for guiding any assessment of a potential subsurface carbon storage site. Employing a suite of 3D seismic attribute analyses (as opposed to relying upon a single attribute) maximizes the chances of identifying geologic anomalies or discontinuities (e.g., faults) that may affect the integrity of a seal that will confine the stored [Formula: see text] in the reservoir. The Illinois Basin, a major area for potential carbon storage, presents challenges for target assessment because geologic anomalies can be ambiguous and easily misinterpreted when using 2D seismic reflection data, or even 3D data, if only conventional display techniques are used. We procured a small 3D seismic reflection data set in the central part of the basin (Stewardson oil field) to experiment with different strategies for enhancing the appearance of discontinuities by integrating 3D seismic attribute analyses with conventional visualizations. Focusing on zones above and below the target interval of the Cambrian Mt. Simon Sandstone, we computed attribute traveltime slices (combined with vertical views) based on discontinuity computations, crossline-directed amplitude change, azimuth of the dip, shaded relief, and fault likelihood attributes. The results provided instructive examples of how discontinuities (e.g., subseismic scale faults) may be almost “invisible” on conventional displays but become detectable and mappable using an appropriate integration of 3D attributes. Strong discontinuities in underlying Precambrian basement rocks do not necessarily propagate upward into the target carbon storage interval. The origin of these discontinuities is uncertain, but we explored a possible strike-slip role that also explains the localization of a structural embayment developed in Lower Paleozoic strata above the basement discontinuities.

Shallow 3D seismic-reflection imaging of fracture zones in crystalline rock

Geophysics ◽  
2007 ◽  
Vol 72 (6) ◽  
pp. B149-B160 ◽  
Author(s):  
Cedric Schmelzbach ◽  
Heinrich Horstmeyer ◽  
Christopher Juhlin
Keyword(s):  
Seismic Reflection ◽  
Crystalline Rock ◽  
Three Dimensions ◽  
Disposal Site ◽  
3D Seismic ◽  
Fracture Zones ◽  
Data Set ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Receiver Array

A limited 3D seismic-reflection data set was used to map fracture zones in crystalline rock for a nuclear waste disposal site study. Seismic-reflection data simultaneously recorded along two roughly perpendicular profiles (1850 and [Formula: see text] long) and with a [Formula: see text] receiver array centered at the intersection of the lines sampled a [Formula: see text] area in three dimensions. High levels of source-generated noise required a processing sequence involving surface-consistent deconvolution, which effectively increased the strength of reflected signals, and a linear [Formula: see text] filtering scheme to suppress any remaining direct [Formula: see text]-wave energy. A flexible-binning scheme significantly balanced and increased the CMP fold, but the offset and azimuth distributions remain irregular; a wide azimuth range and offsets [Formula: see text] are concentrated in the center of the survey area although long offsets [Formula: see text] are only found at the edges of the site. Three-dimensional dip moveout and 3D poststack migration were necessary to image events with conflicting dips up to about 40°. Despite the irregular acquisition geometry and the high level of source-generated noise, we obtained images rich in structural detail. Seven continuous to semicontinuous reflection events were traced through the final data volume to a maximum depth of around [Formula: see text]. Previous 2D seismic-reflection studies and borehole data indicate that fracture zones are the most likely cause of the reflections.

Sign in / Sign up

Export Citation Format

Share Document