Two-dimensional depth migration by cross-correlation of source and reflected wavefields

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dc.contributor.advisorGardner, Gerald H. F.
dc.contributor.committeeMemberAnderson, Wallace L.
dc.contributor.committeeMemberKtonas, Preiklis Y.
dc.contributor.committeeMemberMcDonald, John A.
dc.contributor.committeeMemberJohnson, Olin G.
dc.creatorAgbo, Samuel Onyebuchukwu
dc.date.accessioned2024-01-10T21:02:33Z
dc.date.available2024-01-10T21:02:33Z
dc.date.copyright1984
dc.date.issued1984
dc.description.abstractMost of the existing methods of migrating seismic data are designed for zero source-receiver offset or stacked common midpoint sections. They employ the exploding reflector concept and half the actual velocities. Inherent in the exploding reflector concept is the assumption that the up-going and the down-going raypaths coincide, and that the upward and downward travel times are equal. This assumption is a source of inaccuracy. This dissertation presents a method of migration which could be applied to data collected with various source-receiver layouts, provided the method of data collection could be performed or conceived of as a single experiment or a superposition of such experiments. With this method, a record of the source wavefield is obtained by propagating the source wavefield into the model with the full velocities and the one-way wave equation and storing snapshots of the wavefield at equal time intervals. A record of the reflected wavefield is similarly obtained by reverse time propagation of the recorded time section into the model while also storing snapshots at equal time intervals. Thus, both wavefields are propagated downwards along their correct raypaths, to their points of intersection on the reflectors. True two-dimensional migrations are then produced by properly aligning the two sets of snapshots, cross-multiplying corresponding snapshots, and summing the products. Also presented are experimental verifications of the new method with the migration of both synthetic and physical data. By employing synthetic data generated over a simple model it was shown that, with this method, an accurate image of a simple structure could be obtained by migrating a single shot record. Another experimental verification employed a few single shot records collected over a physical overthrust model. The results show that the migration of a complex geologic model could be achieved by superimposing the migrations of a few single shot records or superimposing the single shot records prior to migration. In a third experimental verification, the shots were so closely spaced that they formed plane waves. Better results were obtained by migrating the plane wave records. By superimposing the migrated depth sections obtained from three plane wave records, further improvements were achieved.
dc.description.departmentElectrical and Computer Engineering, Department of
dc.format.digitalOriginreformatted digital
dc.format.mimetypeapplication/pdf
dc.identifier.other12240157
dc.identifier.urihttps://hdl.handle.net/10657/15899
dc.language.isoen
dc.rightsThis item is protected by copyright but is made available here under a claim of fair use (17 U.S.C. Section 107) for non-profit research and educational purposes. Users of this work assume the responsibility for determining copyright status prior to reusing, publishing, or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires express permission of the copyright holder.
dc.subjectSeismic waves
dc.titleTwo-dimensional depth migration by cross-correlation of source and reflected wavefields
dc.type.dcmiText
dc.type.genreThesis
dcterms.accessRightsThe full text of this item is not available at this time because it contains documents that are presumed to be under copyright and are accessible only to users who have an active CougarNet ID. This item will continue to be made available through interlibrary loan.
thesis.degree.collegeCullen College of Engineering
thesis.degree.departmentElectrical Engineering, Department of
thesis.degree.disciplineElectrical Engineering
thesis.degree.grantorUniversity of Houston
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy

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