Visualization Of Seismic Horizon Attributes
Authors: Dorn G.A. , Cole M.J. , Tubman K.M. 
Published: October 2008

Detailed interpretation of 3-D seismic data is typically performed by picking horizons and faults on orthogonal slices through a 3-D seismic volume. A generalized three-dimensional slice through the data in the shape of the interpreted horizon (horizon-slice) is then be used as a reference along which horizon attributes are interpreted for fault traces, stratigraphic edges and lateral Iithologic changes. Most of this work has been constrained to "map view" displays or flat projections of the interpreted horizon. The actual three-dimensional data variation and the integration of patterns from more than one attribute still must occur in the mind of the interpreter.

It is possible to render the interpreted horizons and attribute data in three dimensions. The interpreted horizon structure defines the shape of a surface, and any combination of attributes may be mapped onto the surface. Frequently, relationship that would take a significant amount of time to detect looking at individual planar displays become strikingly apparent when the data are viewed in three dimensions. Images from severs 3-D surveys clearly show some of the potential of this technology.

Lighting and motion may be used to highlight subtle faulting and texture changes on interpreted horizons. Interactive control of the position of the light source and the observer's viewpoint are essential. They can also be used to highlight temporal relationships between structural elements, and are useful in highlighting areas of poor data or pick quality.

These 3-D displays and movies can play an important role in conveying this complex information to other professionals and to management.

INTRODUCTION

The advent of 3-D seismic surveys in the late. 1970s and early 1980s was a major force behind the development of interactive interpretation systems. Trying to interpret on paper the vast amount of data provided by even those early, relatively small 3D surveys proved to be a daunting task.

Initially, interactive interpretation applications were computer implementations of methods traditionally used by the interpreter to work on paper. Later, applications allowed the generation of displays that would have been very difficult or impossible to create in a paper oriented environment. It became possible to interactively generate random traverses, perform volume autopicking, generate and display map views of attribute variation along interpreted horizons. But most data were still viewed in two dimensions.

Today, interactive interpretation is no longer constrained to two-dimensional displays. The world represented by a 3-D seismic volume consists of three spatial dimensions in which numerous physical parameters vary in a complex fashion. A multitude of parameters varies in a complex fashion in a multi-dimensional space. Three-dimensional data visualization techniques hold vast potential for improving 3-D seismic interpretation.

3D INTERPRETATION FROM 2D DISPLAYS

A 3-D seismic survey is a volume representation of a portion of the subsurface. When an explorationist interprets a 3-D volume, most of the hands on work is done on planar slices through this volume - in-lines, crosslines, and time-slices (Figure 1). In order to provide some three-dimensional insight to the interpreter, most systems also provide for cube or chair displays of the seismic data.