Stratigraphic Resolution Potential Of Marine Seismic Data
Authors: Neidell Norman S. , Lindsey J.P. , Hilterman Fred J. 
Published: October 2008

Marine seismic data offers immediate opportunities for markedly increased stratigraphic resolution owing to seismic modeling and other recent developments. Most of the initial benefits derived from simulating seismic exploration over subsurface models were directed toward structural interpretive applications. Current seismic model studies are providing insights which are principally of stratigraphic nature. For example, the resolution inherent in the usual band of seismic frequencies under appropriate conditions was discovered to be at least three times greater than previously conceived. Additionally, quantitative methods for utilizing marine wavelet processed data are beginning to emerge. Such progress at this early stage of effort suggests more significant results to follow.

INTRODUCTION

Developments in seismic resolution and stratigraphic interpretation draw on existing technology from several differing avenues. In this exposition of recent progress we shall firs1 note the significant steps which arose through seismic modeling. Afterwards we acknowledge the specific contributions of wavelet processing and go on to add a new dimension to our thinking on resolution - seismic amplitude. With these backgrounds we can illustrate certain of the newly developed quantitative approaches to stratigraphic interpretation.

LESSONS FROM SEISMIC MODELING

Seismic model studies employing wave theory calculations have shed much light on diffraction phenomena which up to such time had been a cause of disquiet amongst seismic interpreters. Diffractions were recognized as being associated with sharp curvature of wavefronts or "kinks" and not necessarily directly associated with structural properties. The structural interpretive significance of diffractions as distinct from point reflection signatures is now well understood and documented in the literature by Lindsey and Neidell (9.), Hilterman (7.) and Neidell (11.). Recent interest in diffractions has turned to stratigraphic objectives as exemplified by the task of relating diffraction signatures to the character of termination of a hydrocarbon zone. Such work is largely undocumented.

Offset ray trace modeling has well illuminated the differences between COP stacked sections and normal incidence ray profiles. Additionally, the distinctions between measured stacking velocities and r.m.s. velocities has been made clear.

Perhaps the first modeling study directly addressing questions of stratigraphic identification and resolving thin beds was the work of Lindsey (8.). This paper made use of waveform parameters such as peak-to-trough separation and peak-to-trough ampltiudes as functions of frequency content to attempt to develop interpretive criteria. Symmetric waveforms were considered, and when these could be directly introduced into the seismic data itself by the subsequent discovery of wavelet processing methods, the groundwork for quantitative approaches became complete. The techniques described by Dedman, Lindsey and Schramm (5.) allude to quantitative methods which we described more fully in 'the following discussions.