1887

Abstract

Summary

Vertical seismic profiling (VSP) was tested for mapping volcanic stratigraphy, fractures, dykes, fluid and steam in the geothermal area of Krafla in Iceland. Seismic imaging in magmatic environments is very challenging, largely due to the intense scattering of seismic waves traveling through the highly heterogeneous volcanic rocks. VSP offers means to image structures beneath and away from the well in complex volcanic environments. The VSP survey at Krafla was carried out in two wells, for each of which a zero offset, a far offset and a walk-away experiment were recorded. The zero offset data is of good quality, with the observed reflections corresponding to stratigraphic boundaries that can be explained by a simple 1D velocity model. The corridor stacks of the synthetic and field data look similar to each other, apart from a constant time shift and amplitude differences. High scattering in the subsurface leads to low amplitude reflections from deeper horizons. The walk-away data shows little coherent reflectivity. Furthermore, a complex 2D velocity model involving heterogeneities in the horizontal as well as vertical directions will be required to explain the observed seismograms.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201701098
2017-06-12
2024-03-28
Loading full text...

Full text loading...

References

  1. Bohlen, T., Müller, C., Milkereit, B.
    [2003] Elastic Seismic-Wave Scattering from Massiv Sulfide Orebodies: On the Role of Composition and Shape. In D. W.Eaton, B.Milkereit, and M. H.Salisbury, eds., Hardrock seismic exploration, 70–89.
    [Google Scholar]
  2. Cosma, C., Heikkinen, P., Keskinen, J.
    [2003] Multi-azimuth VSP for rock characterization of deep nuclear waste disposal sites in Finland. In D. W.Eaton, B.Milkereit, and M. H.Salisbury, eds., Hardrock Seismic Exploration, 207–226.
    [Google Scholar]
  3. Elders, W. A., Friöleifsson, G. Ó., Albertsson, A.
    [2014]. Drilling into magma and the implications of the Iceland Deep Drilling Project (IDDP) for high-temperature geothermal systems worldwide. Geothermics, 49, 111–118.
    [Google Scholar]
  4. HersirG. P., Halldórsdóttir, S., Erlendsson, Ö., Gunnarsson, K., Flóvenz, Ó., Giese, R., Kästner, F., Júlíusson, E., Millett, J.M., Planke, S.
    [2016] Summary Report of Task 4.2: Active Seismic With VSP, Reykjavik, Collaborative project: Integrated Methods for Advanced Geothermal Exploration (IMAGE).
    [Google Scholar]
  5. Juhojuntti, N.
    [2001] Seismic imaging of deep crustal reflectivity in Sweden and Iceland. PhD thesis, University of Uppsala.
    [Google Scholar]
  6. Nakagome, O., Toshihiro, U., Takamasa, H.
    [1998] Seismic reflection and VSP in the Kakkonda geothermal field, Japan: fractured reservoir characterization. Geothermics, 27, 535–552.
    [Google Scholar]
  7. Schmelzbach, C., Greenhalgh, S., Reiser, F., Girard, J. F., Bretaudeau, F., Capar, L., Bitri, A.
    [2016] Advanced seismic processing/imaging techniques and their potential for geothermal exploration. Interpretation, 4, SR1–SR18.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201701098
Loading
/content/papers/10.3997/2214-4609.201701098
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error