Phases of a seismic project
Exploring for Oil and Gas Traps | |
Series | Treatise in Petroleum Geology |
---|---|
Part | Predicting the occurrence of oil and gas traps |
Chapter | Interpreting seismic data |
Author | Christopher L. Liner |
Link | Web page |
Store | AAPG Store |
Generally speaking, there are three phases of a seismic project:
- Acquisition
- Processing
- Interpretation
In this chapter we concentrate on interpretation, but it is hard to ignore the importance of the other phases.
Acquisition
A good interpreter knows the basics of seismic survey design and can recognize problems when they arise. Even a well-designed survey can be ruined by sloppy acquisition methods. Common culprits are poor positioning or cabling information (i.e., which receivers are live for which shots). For more information about acquisition, please see Seismic data acquisition on land and Marine seismic data acquisition.
A3-D seismic survey is designed to give optimum results for a particular depth interval containing the target(s). If there are design, acquisition, or processing problems, then the data may contain artifacts. These are most commonly seen as map-view amplitude patterns and are called an acquisition footprint. One should avoid footprints because they can mask or confuse geologic patterns in the data.
Processing
Raw seismic data look as much like an image of the earth as a hamburger looks like a cow. An enormous amount of computer and human effort is required to transform raw seismic data into a usable image. Each step involves many user-supplied parameters that can change the result—maybe a little, maybe a lot. In short, processing should rightly be coupled with the interpretation process since the processor makes decisions affecting data quality. However, this is rarely the case because few individuals possess sufficient expertise in both areas.
Getting the most from seismic data
In a perfect world, one person or a small team would design, oversee acquisition of, process, and interpret a seismic survey. All too often, an off-the-shelf design is shot by a low-bid contractor, processed with standard flow and parameters, then delivered for interpretation. The company that breaks out of this cycle of mediocrity can expect to pay more but can also achieve a competitive advantage.
See also
- Recurring themes
- 3-D seismic: the data cube
- Components of a 3-D seismic survey
- 3-D seismic data views