S-wave Reflection Seismic Exploration of a Shallow Sediment Body - A Case Study at Alfbach Valley, Vulkaneifel, Germany

Abstract. We present the pre-stack depth imaging results for a case study of 3D reflection seismic exploration at the Blötberget iron-oxide mining site belonging to the Bergslagen mineral district in central Sweden. The goal of this case study is to directly image the ore-bearing units and to map its possible extension down to greater depths than known from existing boreholes. Therefore, we applied a tailored pre-processing workflow as well as two different seismic imaging approaches, Kirchhoff pre-stack depth migration and Fresnel Volume Migration (FVM). Both imaging techniques deliver a well resolved 3D image of the deposit and its host rock, where the FVM image yields a significantly better image quality compared to the KPSDM image. We were able to unravel distinct reflection horizons, which are linked to known mineralisation and provide insights on lateral and depth extent of the deposits beyond their known extension from borehole data. A comparison of the known mineralization and the image show a good agreement of the position and the shape of the imaged reflectors caused by the mineralization. Furthermore, the images show a reflector, which is interpreted to be a fault intersecting the mineralisation and which can be linked to the surface geology. The depth imaging results can serve as the basis for further investigations, drillings and follow-up mine planning at the Blötberget mining site.

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Wave equation datuming applied to S-wave reflection seismic data

Journal of Applied Geophysics ◽

10.1016/j.jappgeo.2018.03.015 ◽

2018 ◽

Vol 152 ◽

pp. 167-172 ◽

Cited By ~ 2

Author(s):

U. Tinivella ◽

M. Giustiniani ◽

R. Nicolich

Keyword(s):

Wave Equation ◽

Seismic Data ◽

Wave Reflection ◽

S Wave ◽

Reflection Seismic

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The Signature of a Small-throw Fault Affecting Unconsolidated Sediments in S-wave Reflection Seismic Data

74th EAGE Conference and Exhibition incorporating EUROPEC 2012 ◽

10.3997/2214-4609.20148178 ◽

2012 ◽

Author(s):

J. P. Carvalho ◽

R. Ghose ◽

A. Loureiro

Keyword(s):

Seismic Data ◽

Wave Reflection ◽

Unconsolidated Sediments ◽

S Wave ◽

Reflection Seismic

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Comment on Shear wave reflection seismic yields subsurface dissolution and subrosion patterns: application to the Ghor Al-Haditha sinkhole site, Dead Sea, Jordan by Polom et al. (2018)

10.5194/se-2019-132 ◽

2019 ◽

Author(s):

Michael Ezersky ◽

Anatoly Legchenko ◽

Lev Eppelbaum ◽

Abdallah Al-Zoubi ◽

Abdelrahman Abueladas

Keyword(s):

Shear Wave ◽

Seismic Data ◽

Seismic Reflection ◽

Wave Reflection ◽

Dead Sea ◽

S Wave ◽

Reflection Seismic ◽

Salt Layer ◽

Wave Technique

Abstract. Seismic reflection S-wave technique is very effective and has demonstrated nice results in previous investigations of various authors. However, the salt layer was not detected in the Ghor Al-Haditha area (Jordan) because of some reasons. The main reason is that about ~ 80 % of reflection lines were carried outside the salt area delineated by Ezersky et al. (2013b) based on results of El-Isa et al. (1995). Other possible factor is too strong filtering of seismic data obtained from the upper part of the section (up to 50 m deep). Our and Polom (2018) assessment of the work of other authors diverges. We affirm that the salt layer of 7–10 m thickness is located at ~ 40 m depth in the Ghor Al-Haditha area.

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A COMPARATIVE CASE STUDY OF REFLECTION SEISMIC IMAGING METHOD

10.1130/abs/2017am-308144 ◽

2017 ◽

Author(s):

Moones Alamooti ◽

◽

Adnan Aydin

Keyword(s):

Seismic Imaging ◽

Comparative Case Study ◽

Imaging Method ◽

Reflection Seismic

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S-wave experiments for the exploration of a deep geothermal carbonate reservoir in the German Molasse Basin

Geothermal Energy ◽

10.1186/s40517-021-00189-w ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Britta Wawerzinek ◽

Hermann Buness ◽

Hartwig von Hartmann ◽

David C. Tanner

Keyword(s):

Upper Jurassic ◽

Carbonate Reservoir ◽

P Wave ◽

Seismic Survey ◽

Seismic Exploration ◽

Molasse Basin ◽

S Wave ◽

Induced Earthquakes ◽

Conversion Point ◽

Facies Classification

AbstractThere are many successful geothermal projects that exploit the Upper Jurassic aquifer at 2–3 km depth in the German Molasse Basin. However, up to now, only P-wave seismic exploration has been carried out. In an experiment in the Greater Munich area, we recorded S-waves that were generated by the conventional P-wave seismic survey, using 3C receivers. From this, we built a 3D volume of P- to S-converted (PS) waves using the asymptotic conversion point approach. By combining the P-volume and the resulting PS-seismic volume, we were able to derive the spatial distribution of the vp/vs ratio of both the Molasse overburden and the Upper Jurassic reservoir. We found that the vp/vs ratios for the Molasse units range from 2.0 to 2.3 with a median of 2.15, which is much higher than previously assumed. This raises the depth of hypocenters of induced earthquakes in surrounding geothermal wells. The vp/vs ratios found in the Upper Jurassic vary laterally between 1.5 and 2.2. Since no boreholes are available for verification, we test our results against an independently derived facies classification of the conventional 3D seismic volume and found it correlates well. Furthermore, we see that low vp/vs ratios correlate with high vp and vs velocities. We interpret the latter as dolomitized rocks, which are connected with enhanced permeability in the reservoir. We conclude that 3C registration of conventional P-wave surveys is worthwhile.

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