Fundamentals of 3D Seismic Volume Visualization

Abstract

Abstract Since the early 1980's, the volume of 3D seismic data has been steadily growing. Beyond the increase in size and number of 3D seismic surveys, there is also proliferation of attribute data. This increase places additional demands on the interpreter that is difficult to meet using traditional mainstream interpretation methods. A key element in solving this interpretation problem is the application of 3D volume visualization, which introduces new technologies and requires new skills. It enables the geoscientists to extract tremendous amounts of information in short periods of time. To maximize benefits, skills in the art of volume visualization must be established. Grasping the fundamentals of 3D seismic volume visualization provides a foundation for growth and creative solutions. Essential fundamental concepts and visualization processes, namely the Zone System, are discussed with examples of its application on stratigraphic, structural and amplitude interpretation problems. Important interpretation considerations, and discussions on color, and key strategies for quality visualization are included. Introduction 3D volume visualization is a method of seismic interpretation in which the interpreter directly evaluates the seismic reflectivity of the subsurface in three-dimensional space by applying various levels of transparency to the data. The technology and philosophy of 3D volume visualization1 differs from conventional interpretation and includes new interpretation strategies and methodology. Through direct integration of structural, stratigraphic and amplitude data, both regional and prospect-specific details can be revealed and evaluated prior to significant digital interpretation. This helps the interpreter to design an efficient work plan to achieve higher quality interpretations in a shorter period of time. Visualization Types There are two basic types of visualization: surface and volume. Surface visualization is the result of mapping individual horizons and faults, and then re-interpreting them collectively in 3D space as a 3D model. This method is time-consuming, involving two major interpretation steps and utilizes only a portion of the 3D data. Volume visualization assumes that the reflectivity of the subsurface provides enough detail to allow interpreters to directly evaluate and integrate structural, stratigraphic and amplitude features in 3D space. Both 3D regional and prospect-specific evaluations, including the identification of potential fluid contacts, can be performed quickly in detail. In contrast to surface visualization, a large percentage of the data volume is often evaluated. Interpretation Considerations In general, conventional interpretation methods produce maps, while volume visualization methods produce 3D perspectives. When the purpose of the task is specific, we normally make a map.