Parameters effective on estimating a nonstationary mixed-phase wavelet using cumulant matching approach.
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| Title: | Parameters effective on estimating a nonstationary mixed-phase wavelet using cumulant matching approach. |
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| Authors: | Vosoughi, Ehsan1, Javaherian, Abdolrahim1,2 javaheri@ut.ac.ir |
| Source: | Journal of Applied Geophysics. Jan2018, Vol. 148, p83-97. 15p. |
| Subjects: | Seismology, Acoustic impedance, Wavelets (Mathematics), Cumulants, Windows (Graphical user interfaces) |
| Abstract: | Seismic inversion is a process performed to remove the effects of propagated wavelets in order to recover the acoustic impedance. To obtain valid velocity and density values related to subsurface layers through the inversion process, it is highly essential to perform reliable wavelet estimation such as cumulant matching approach. For this purpose, the seismic data were windowed in this work in such a way that two consecutive windows were only one sample apart. Also, we did not consider any fixed wavelet for any window and let the phase of each wavelet rotate in each sample in the window. Comparing the fourth order cumulant of the whitened trace and fourth-order moment of the all-pass operator in each window generated a cost function that should be minimized with a non-linear optimization method. In this regard, parameters effective on the estimation of the nonstationary mixed-phase wavelets were tested over the created nonstationary seismic trace at 0.82 s and 1.6 s. Besides, we compared the consequences of each parameter on estimated wavelets at two mentioned times. The parameters studied in this work are window length, taper type, the number of iteration, signal-to-noise ratio, bandwidth to central frequency ratio, and Q factor. The results show that applying the optimum values of the effective parameters, the average correlation of the estimated mixed-phase wavelets with the original ones is about 87%. Moreover, the effectiveness of the proposed approach was examined on a synthetic nonstationary seismic section with variable Q factor values alongside the time and offset axis. Eventually, the cumulant matching method was applied on a cross line of the migrated data from a 3D data set of an oilfield in the Persian Gulf. Also, the effect of the wrong Q estimation on the estimated mixed-phase wavelet was considered on the real data set. It is concluded that the accuracy of the estimated wavelet relied on the estimated Q and more than 10% error in the estimated value of Q is acceptable. Eventually, an 88% correlation was found between the estimated mixed-phase wavelets and the original ones for three horizons. The estimated wavelets applied to the data and the result of deconvolution processes was presented. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Applied Geophysics is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Parameters effective on estimating a nonstationary mixed-phase wavelet using cumulant matching approach. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Vosoughi%2C+Ehsan%22">Vosoughi, Ehsan</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Javaherian%2C+Abdolrahim%22">Javaherian, Abdolrahim</searchLink><relatesTo>1,2</relatesTo><i> javaheri@ut.ac.ir</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Applied+Geophysics%22">Journal of Applied Geophysics</searchLink>. Jan2018, Vol. 148, p83-97. 15p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Seismology%22">Seismology</searchLink><br /><searchLink fieldCode="DE" term="%22Acoustic+impedance%22">Acoustic impedance</searchLink><br /><searchLink fieldCode="DE" term="%22Wavelets+%28Mathematics%29%22">Wavelets (Mathematics)</searchLink><br /><searchLink fieldCode="DE" term="%22Cumulants%22">Cumulants</searchLink><br /><searchLink fieldCode="DE" term="%22Windows+%28Graphical+user+interfaces%29%22">Windows (Graphical user interfaces)</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Seismic inversion is a process performed to remove the effects of propagated wavelets in order to recover the acoustic impedance. To obtain valid velocity and density values related to subsurface layers through the inversion process, it is highly essential to perform reliable wavelet estimation such as cumulant matching approach. For this purpose, the seismic data were windowed in this work in such a way that two consecutive windows were only one sample apart. Also, we did not consider any fixed wavelet for any window and let the phase of each wavelet rotate in each sample in the window. Comparing the fourth order cumulant of the whitened trace and fourth-order moment of the all-pass operator in each window generated a cost function that should be minimized with a non-linear optimization method. In this regard, parameters effective on the estimation of the nonstationary mixed-phase wavelets were tested over the created nonstationary seismic trace at 0.82 s and 1.6 s. Besides, we compared the consequences of each parameter on estimated wavelets at two mentioned times. The parameters studied in this work are window length, taper type, the number of iteration, signal-to-noise ratio, bandwidth to central frequency ratio, and Q factor. The results show that applying the optimum values of the effective parameters, the average correlation of the estimated mixed-phase wavelets with the original ones is about 87%. Moreover, the effectiveness of the proposed approach was examined on a synthetic nonstationary seismic section with variable Q factor values alongside the time and offset axis. Eventually, the cumulant matching method was applied on a cross line of the migrated data from a 3D data set of an oilfield in the Persian Gulf. Also, the effect of the wrong Q estimation on the estimated mixed-phase wavelet was considered on the real data set. It is concluded that the accuracy of the estimated wavelet relied on the estimated Q and more than 10% error in the estimated value of Q is acceptable. Eventually, an 88% correlation was found between the estimated mixed-phase wavelets and the original ones for three horizons. The estimated wavelets applied to the data and the result of deconvolution processes was presented. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Applied Geophysics is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.jappgeo.2017.10.016 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 15 StartPage: 83 Subjects: – SubjectFull: Seismology Type: general – SubjectFull: Acoustic impedance Type: general – SubjectFull: Wavelets (Mathematics) Type: general – SubjectFull: Cumulants Type: general – SubjectFull: Windows (Graphical user interfaces) Type: general Titles: – TitleFull: Parameters effective on estimating a nonstationary mixed-phase wavelet using cumulant matching approach. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Vosoughi, Ehsan – PersonEntity: Name: NameFull: Javaherian, Abdolrahim IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 01 Text: Jan2018 Type: published Y: 2018 Identifiers: – Type: issn-print Value: 09269851 Numbering: – Type: volume Value: 148 Titles: – TitleFull: Journal of Applied Geophysics Type: main |
| ResultId | 1 |
