Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Laurain, R. Articles by Strand, C. Search for Related Content GeoRef GeoRef Citation

Simulated migration amplitude for improving amplitude estimates in seismic illumination studies

Norsar, Kjeller, Norway

Christian Strand

PGS, Oslo, Norway

Corresponding author: renaud.laurain@norsar.com

The first 20% of the full text of this article appears below.

Ideally, a seismic data cube should contain amplitudes that are proportional to the reflectivity of the subsurface. However, when working with real data, the seismic amplitudes used for interpretation are highly dependent on other factors such as survey geometry, instrumentation, filtering and muting of prestack data, migration artifacts, focusing/defocusing, wave attenuation in the overburden, and several other factors. When an amplitude variation is encountered in the seismic data, determining which factor is responsible is not easy. In this paper we apply a method based on a combination of 3D seismic ray modeling and simulation of migration that is able to distinguish between some factors contributing to the amplitudes. This will reduce the risk of interpreting "false" anomalies and drilling dry wells.

The method, presented in Laurain and Vinje (2001), is an extension of work proposed by Schneider and Winbow (1999). It is computationally efficient and is thus well suited for survey planning where the amplitude response of several surveys is to be compared.

We show the results of the method in a real case where the real amplitudes and the new simulated migration amplitudes (SMA) have striking similarities. We compare the results with various types of conventional illumination maps that can be generated from ray tracing such as hit maps and illumination amplitude maps.

	Background

 
In conventional illumination mapping, 3D forward ray tracing of reflected rays coupled with target-oriented binning methods are extensively used to study the illumination of a particular target horizon in depth. Various attributes from ray-traced reflections are summed within bin cells on the target reflector to provide illumination maps. Counting the number of hits in each bin cell generates a hitmap. Summing the amplitudes of all rays that fall into each bin cell generates the illumination amplitude map (Figure 1). This mapping process associates a . . . [Full Text of this Article]