Voxel Technology
Authors: Roberts David M. 
Published: October 2008

Voxel technology has recently become widely available to geoscientists in the form of advanced 3D seismic interpretation software. This paper discusses the power of this relatively new technology which potentially allows a step change in the speed with which 3D seismic data can be interpreted. In addition, powerful new analytical functionality is now available which for example allows amplitude connectivity to be very quickly evaluated, and more than one 3D survey to be interpreted at the same time. The objective of the paper is to encourage geoscientists to use voxel technology to assist in the interpretation of 3D seismic data. The value of much faster, and more robust 3D seismic interpretation is clearly linked to the business drive for faster seismic cycle times, and accelerated exploration and field development and production.

Introduction

Voxel technology has recently become widely available to geoscientists in the form of advanced 3D seismic interpretation software. Several vendors market voxel based interpretation systems either as standalone applications, or as part of their integrated interpretation platforms.

3D seismic interpretation turnaround time

Voxel technology differs from that used in conventional workstation design, in that all the seismic trace data is stored in memory (RAM). This leads to a step change in speed in terms of data access time which has a corresponding very positive impact on the time that it takes to interpret a 3D seismic dataset. Faster 3D seismic interpretation is clearly linked to the business drive for faster seismic cycle times, and accelerated exploration, and field development and production.

3D seismic interpretation'in real 3D'

A further benefit of using Voxel based software to interpret 3D seismic data is that it is possible to interpret the data 'in real 3D'. Instead of interpreting in lines, crosslines and timeslices from a 3D seismic dataset, it is now possible to display and interpret a complete 3D seismic cube on a workstation screen in 3D. This has major benefits in allowing the interpretation and visualization of 3D seismic data in a way that results in a much faster understanding of the geological significance of the dataset. Although voxel based interpretation systems were initially considered to only work well in good data areas, and where reservoirs and/or hydrocarbons are represented by amplitude anomalies, we now conclude that they are equally useful in poor dilta qualily areas. The ability to animate, or pan through, any dataset in real-time can allow the identification of subtle features which might otherwise have been overlooked. Such techniques also allow more confidence to be established in the interpretation of poorer quality datasets, by for example animating through 'squash' volumes.

Connectivity analysis and 'sculpting'

Voxel based interpretation systems are particularly well suitedfor analyzing the connectivity of seismic amplitude anomalies. This works particularly well on acoustic impedance datasets where a reservoir is well resolved, for example as a high porosity acoustic impedance trough. Voxel technology also allows 3D seismic volumes to be 'sculpted'. For example, a top and base reservoir interpretation can be used to 'sculpt out' the seismic between the top and base reservoir.