Imaging sub-basalt structures using locally converted waves

Baan, Mirko van der; Kerrane, T.; Kendall, J. M.; Taylor, Nicola C.

doi:10.3997/1365-2397.2003009

Cited by 4 publications

(4 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the Slyne Trough data, a comparison of PP and mode‐converted depth sections showed that the latter imaged coherent events deeper below the shallow volcanics than the former, a result which has been reported elsewhere (e.g. Emsley et al 1998; van der Baan et al . 2003), but which has not seen universal applicability (Hanssen et al 2003).…”

supporting

confidence: 71%

Imaging through Altantic Margin basalts: An introduction to the sub‐basalt mini‐set

Christie

White

2007

Geophysical Prospecting

View full text Add to dashboard Cite

supporting

confidence: 71%

Imaging through Altantic Margin basalts: An introduction to the sub‐basalt mini‐set

Christie

White

2007

Geophysical Prospecting

View full text Add to dashboard Cite

“…P-wave anisotropy have been observed using wide angle active seismic data 37 and measured in samples collected in geothermal fields (up to 20% in Larderello) 38 . Until now, mapping the presence of vapor-filled microcracks from observations of P-wave velocity anisotropy at depth implies extensive and cost-expensive active seismic survey, but resolution given by active seismic techniques is generally low beneath high-reflectivity horizons 39 , compromising the ability of mapping the change from ultra-high anisotropic to isotropic materials.…”

Section: Discussionmentioning

confidence: 99%

Discovering geothermal supercritical fluids: a new frontier for seismic exploration

Agostinetti

Licciardi

Piccinini

et al. 2017

Sci Rep

View full text Add to dashboard Cite

Exploiting supercritical geothermal resources represents a frontier for the next generation of geothermal electrical power plant, as the heat capacity of supercritical fluids (SCF),which directly impacts on energy production, is much higher than that of fluids at subcritical conditions. Reconnaissance and location of intensively permeable and productive horizons at depth is the present limit for the development of SCF geothermal plants. We use, for the first time, teleseismic converted waves (i.e. receiver function) for discovering those horizons in the crust. Thanks to the capability of receiver function to map buried anisotropic materials, the SCF-bearing horizon is seen as the 4km-depth abrupt termination of a shallow, thick, ultra-high (>30%) anisotropic rock volume, in the center of the Larderello geothermal field. The SCF-bearing horizon develops within the granites of the geothermal field, bounding at depth the vapor-filled heavily-fractured rock matrix that hosts the shallow steam-dominated geothermal reservoirs. The sharp termination at depth of the anisotropic behavior of granites, coinciding with a 2 km-thick stripe of seismicity and diffuse fracturing, points out the sudden change in compressibility of the fluid filling the fractures and is a key-evidence of deep fluids that locally traversed the supercritical conditions. The presence of SCF and fracture permeability in nominally ductile granitic rocks open new scenarios for the understanding of magmatic systems and for geothermal exploitation.

show abstract

“…According to the elastic migration principle (Kuo & Dai, 1984), we migrated data using a combination of velocities and event enhancement amplitude weights suitable for each event. This makes it possible to avoid misprocessing and misinterpreting non-PP arrivals as primary PP reflections, without applying labourintensive pre-processing that involves the use of handpicked mutes or interactive interpretations based on calculations of the traveltime response (Barzaghi et al, 2002;Van der Baan et al, 2003). In event-based migration with accurate velocities, migrated energy from assumed wave-propagation modes coincides with the actual reflector, although different parts of this reflector are imaged with each event (Kuo & Dai, 1984).…”

Section: Introductionmentioning

confidence: 99%

“…The precise mechanism for such noise varies from case to case (Martini & Bean, 2002;Maresh & White, 2005). Preliminary multi-wave-type or eventbased imaging, illumination and forward modelling studies (Purnell, 1992;Barzaghi et al, 2002;Van der Baan et al, 2003) have been particularly encouraging, suggesting the possibility of imaging beneath HVLs using converted waves generated at the interface between formations with strong velocity contrast. Traditionally, wide-angle data have been used to derive a starting large-scale velocity model by traveltime inversion (Fruehn et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

A study of sub-basalt depth imaging using the local Radon attributes on the Erlend Tertiary volcanic complex - North of Shetland, UK

Droujinine

Pajchel

Hitchen

2008

Netherlands Journal of Geosciences

View full text Add to dashboard Cite

IAcquiring conventional 3 km towed streamer data along a 2D profile in the North of Shetland (UK) enables us to use the local Radon-attributes within the context of depth processing methodology for accurate delineation of volcanic units and imaging beneath high-velocity layers. The objective is to map the radially-dipping structure of the Erlend pluton and to investigate the potential existence of relatively soft Cretaceous sediments underneath volcanic units. Success in the Erlend Volcano study requires strict attention to the separation between different groups of events. The crucial point is the generalized discrete Radon transform formulated in terms of local wavefront (dip and curvature) characteristics. This transform is utilized during pre-CMP processing and migration to minimize event-coupling artefacts. These artefacts represent cross-talk energy between various wave modes and include the unwanted part of the wavefield. We show how to produce detailed subsurface images within the region of interest (exploration prospect only) by applying the closely tied processes of prestack event enhancement and separation, well-driven time processing for velocity model building, and final event-based prestack depth imaging. Results show enhanced structural detail and good continuity of principal volcanic units and deeper reflections, suggesting a faulted 0.6 -0.9 km thick layer of Cretaceous sediments in the proximity of well 209/09-1. Our interpretation complements existing low-resolution geophysical models inferred from gravity and wide-angle seismic data alone.

show abstract

Imaging sub-basalt structures using locally converted waves

Cited by 4 publications

References 14 publications

Imaging through Altantic Margin basalts: An introduction to the sub‐basalt mini‐set

Imaging through Altantic Margin basalts: An introduction to the sub‐basalt mini‐set

Discovering geothermal supercritical fluids: a new frontier for seismic exploration

A study of sub-basalt depth imaging using the local Radon attributes on the Erlend Tertiary volcanic complex - North of Shetland, UK

Contact Info

Product

Resources

About