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Quantification of signal and noise in two-way transmitted wavefields to improve well ties in Cooper Basin, Australia

Chen Qi and Fred Hilterman
Quantification of signal and noise in two-way transmitted wavefields to improve well ties in Cooper Basin, Australia (in Well ties to seismic data, Donald A. Herron (prefacer), Robert C. Wegner (prefacer), Rachel T. Newrick (prefacer) and John R. Sumner (prefacer))
Interpretation (Tulsa) (May 2014) 2 (2): SD19-SD31

Abstract

Permian coal beds at 2400-2900 m depth in Cooper Basin, Australia have normal-incident reflection coefficient values as large as + or -0.6. If internal multiples are included in synthetic seismograms, excellent correlations exist between the synthetic seismogram and seismic, even when more than 50 coal beds are present. However, neither the synthetic seismogram nor the seismic tie the well-log lithologic boundaries because the incident wavefield that strikes a lithologic boundary and returns to the surface contains a signal wavelet followed by high-amplitude noise, which are interbed multiple reflections. Because the spectra of the signal and noise coda at a given two-way time normally do not overlap, time-varying Gaussian filters applied to the near-offset stack enhance the signal and suppress the noise coda. After filtering, the apparent time delay of reflections introduced by the coal beds is removed with variable time shifts (time compression), based on the estimated time-varying signal wavelets. The two-step process of low-pass filtering and compression yields seismic events that successfully tie the lithologic boundaries in the borehole, although with limited resolution. Our preliminary tests on a seismic line indicate that the horizon event associated with the base of a 500-m-thick coal sequence is more coherently imaged with our processing than with conventional processing.


ISSN: 2324-8858
EISSN: 2324-8866
Serial Title: Interpretation (Tulsa)
Serial Volume: 2
Serial Issue: 2
Title: Quantification of signal and noise in two-way transmitted wavefields to improve well ties in Cooper Basin, Australia
Title: Well ties to seismic data
Author(s): Qi, ChenHilterman, Fred
Author(s): Herron, Donald A.prefacer
Author(s): Wegner, Robert C.prefacer
Author(s): Newrick, Rachel T.prefacer
Author(s): Sumner, John R.prefacer
Affiliation: University of Houston, Houston, TX, United States
Affiliation: Consultant, Sugar Land, TX, United States
Pages: SD19-SD31
Published: 201405
Text Language: English
Publisher: Society of Exploration Geophysicists, Tulsa, OK, United States
References: 14
Accession Number: 2015-007004
Categories: Economic geology, geology of energy sourcesApplied geophysics
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. chart, sects., sketch map
S29°00'00" - S10°00'00", E138°00'00" - E153°00'00"
S38°00'00" - S26°00'00", E129°00'00" - E141°00'00"
Secondary Affiliation: Wegner Geophysics, USA, United StatesRacian Ventures, CAN, CanadaSumner Geophysics, USA, United StatesGeokinetics, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by Society of Exploration Geophysicists, Tulsa, OK, United States
Update Code: 201504
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