Print Email Facebook Twitter Adaptive deghosting of seismic data: A power-minimization approach Title Adaptive deghosting of seismic data: A power-minimization approach Author Schuberth, M.G. Contributor Kamil Amin, Y.I. (mentor) Caprioli, P. (mentor) Vassallo, M. (mentor) Van Manen, D.J. (mentor) Faculty Civil Engineering and Geosciences Department Geoscience & Engineering Programme Applied Geophysics and Petrophysics Date 2015-08-28 Abstract In marine seismic acquisitions, a major deteriorating effect on resolution is caused by ghost re- flections. Sensors towed at depth within a water column record not only the desired up-going wavefield reflected from geological formations, but also its reflections from the sea surface known as down-going wavefield, or seismic ghost. This generates notches in the spectrum of the measured wavefield, reducing significantly the usable bandwidth and hence the resolution of the seismic data. Recently, the removal of the ghost (‘deghosting’) has attracted increasing attention with the aim of obtaining more broadband data. In particular, improved deghosting promises to bring value to both legacy and newly acquired data in terms of high signal to noise ratio across a wide range of frequencies. Deterministic deghosting techniques assume a perfectly known ghost model. Unfortunately, environmental effects causing cable positioning errors and poor crossline sampling in marine seismic acquisition can cause deviations from a deterministic ghost model. As a result, this demands strong and often unrealistic assump- tions, such as exclusive inline propagation, a perfectly flat sea surface, or exactly positioned receivers. Additional measurements try to overcome these limitations, however, this is gener- ally expensive, thus motivating an adaptive deghosting approach for single sensor acquisitions. This thesis proposes a novel, simple and fast algorithm to effectively remove the ghost, based on a sequential approach that first estimates the ghost delay parameter through power min- imization of a hypothetical up-going wavefield, and deghosts the data in a final step. The algorithm was applied to real data and compared to current approaches, showing encouraging results. Through its simplicity and speed, the proposed method is largely domain independent and offers many opportunities to be extended. Subject adaptive deghostingmarine seismic To reference this document use: http://resolver.tudelft.nl/uuid:a01495d7-c791-4113-968e-4c2925b74aa1 Embargo date 2015-08-09 Part of collection Student theses Document type master thesis Rights (c) 2015 Schuberth, G.M. Files PDF MSc_Schuberth.pdf 8.03 MB Close viewer /islandora/object/uuid:a01495d7-c791-4113-968e-4c2925b74aa1/datastream/OBJ/view