With better imaging than traditional 3D and declining costs, multicomponent technology promises to have positive impacts throughout the E&P cycle.

In recent years the development of marine four-component (4C) acquisition and processing technology has made it possible to use the technique in most geographical areas and in a wide range of water depths.
Despite the recent downturn and subsequent restructuring of the industry in general, 4C technology has moved forward and become more accepted.
What is going on?
Imaging of structures beneath gas clouds is a well-established application of this technology. Several 4C/3D surveys have been acquired lately, and more will be acquired in the near future to solve this particular problem. Geographically these surveys stretch from the Gulf of Mexico to the North Sea and various regions of the Asia-Pacific region.
Imaging of low-impedance compressional (P) wave reservoirs is also gaining acceptance, and surveys have been shot or are planned in various parts of the world.
Also encouraging is the fact that surveys have been shot with more ambitious goals like fracture detection and fluid discrimination. These applications may prove to be the biggest volume, but the industry still has a lot to learn in terms of processing and analysis.
Last, but not least, is an emerging application of seabed acquisition techniques related to the use of a 4C subset, the dual sensor, for improved P-wave imaging. Key words here are multiple suppression improvement and advantages related to wide azimuth imaging or wave-field imaging techniques. Associated with this is reservoir monitoring and 4D. 4C and 4D may prove to have a closer link than expected.
When should it be used?
Seen from an oil company perspective, the technology will be relevant for the main phases of a field: exploration, appraisal and production.
In the exploration phase, it will definitely help geoscientists find new plays, especially those stratigraphic plays that are invisible on the conventional P-wave data or are obscured by the presence of gas.
For the appraisal phase, significant improvement is expected in speed and decision quality in the planning of field production scenarios. Lithology and reservoir quality prediction are key possibilities here.
In the production phase, 4C will be used for reservoir description and enhanced recovery purposes. Given the quality of today's navigation, it also should become a significant 4D tool.
Overall, this technology will be used as a significant risk-reduction tool in all three phases.
Is it cost-efficient?
When towed streamer 3D was introduced, many objections similar to those encountered today regarding reliability and quality were raised. Many argued 2D was good enough and felt 3D was too expensive. The combination of geophysical success and technology development that brought the cost down contributed to its success. Few today will say streamer 3D is not cost-efficient.
When 4C was introduced some 5 years ago, the cost was in the order of US $100,000 per square kilometer. Since then it has been reduced significantly, but customers still complain this technology is too expensive. Technology will bring the cost down farther, but it is fair to say that at this stage, 4C already is cost-efficient for many applications.
The appraisal phase is likely to be where the technology is first used in a large volume. This is where important, long-lasting decisions are made and significant funds are available. The more one knows about the reservoir, the more cost-efficient the development strategy can be.
In a report evaluating the cost overruns on several recent field developments in Europe, increased drilling cost is identified as one of the main contributors. For the 10 fields investigated, the initial drilling and completion cost represents 28% of the total, while the average cost for later drilling and completion is 42%.
In the appraisal phase, the 4C method will be used to make better images, identify reservoir quality throughout the reservoir and possibly map fluid distribution.
Just as conventional 3D has been used for risk reduction in the exploration phase, 4C will be used for risk reduction in the appraisal phase. The time factor and fast-track development make it even more important.
Another factor is drilling cost. Therefore, 4C will be used increasingly in deep water to minimize risk prior to drilling at any stage in the exploration-production phase.
Near-term development
More equipment is being put on the seabed, and therefore unit cost is coming down. This will only improve as the market grows.
Challenges remain on the processing and interpretation side. The need for depth imaging and to account for anisotropy is widely acknowledged. But with increased volume, the service providers will be encouraged to develop tools and methods that will further increase the use of the technology similar to that of conventional 3D more than a decade ago.