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A Probabilistic Model for Ghost Delay Time Estimation Based on Recording Geometry
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 79th EAGE Conference and Exhibition 2017, Jun 2017, Volume 2017, p.1 - 5
Abstract
Summary
An estimate of the ghost operator is required to deconvolve the ghost response from marine seismic data. Typically, this estimate is made using a model of in-plane propagation: that is that the raypath at the receiver falls in the vertical plane defined by the source and receiver locations. Unfortunately this model breaks down when the source is in a crossline position relative to the receiver spread. In this paper, we model the posterior probability distribution functions for the vertical component of the ray vector (or equivalently ghost-delay time) given the known source azimuth and the measured inline component of dip of the wave in the plane of the streamer. The model is fairly robust with regards to the prior assumptions, and controlled by a single parameter that is related to the likelihood of in-plane propagation. The expected values of the resulting distributions are consistent with the deterministic in-plane model when in-plane likelihood is high, but valid everywhere in the signal cone. Relaxing the in-plane likelihood to a reasonable degree, radically simplifies the shape of the expected-value surface, lending itself for use in deghosting algorithms. The model can also be extended to other plane-wave processing problems, such as interpolation.
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