About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

GCAGS Transactions

Abstract


Gulf Coast Association of Geological Societies Transactions Vol. 58 (2008), Pages 455-460

EXTENDED ABSTRACT: Illuminating Previous HitSeismicNext Hit Stratigraphic Features Using 3D Visualization

Huw James

Paradigm, 820 Gessner Rd., Ste. 400, Houston, Texas 77024

EXTENDED ABSTRACT

Interpreters use a variety of workflows when performing structural interpretation of Previous HitseismicNext Hit Previous HitdataNext Hit and these workflows are fairly easy to turn into procedures that can be followed by other members of the team. Visualization of 3D Previous HitseismicNext Hit Previous HitdataNext Hit enables interpreters to scan volumes and reveal stratigraphic features. Interpreters can choose to work with amplitude volumes, attribute volumes or mixtures of both. The volumes can be datumed relative to the current sea-level surface, historical surfaces, or flattened horizons. The interpreter can sculpt, varying opacity and lighting to deliver a huge number of potential results. The outcomes can be so numerous that it becomes difficult to know where to stop in this process. Examples from a Previous HitdataNext Hit set from offshore Indonesia are below. The reader is referred to Yilmaz (2001) for additional information and views of this particular Previous HitdataNext Hit set.

Amplitude Previous HitDisplayNext Hit and Combined Amplitude with Coherency Previous HitDisplayNext Hit

Interpreters have traditionally used coherency displays to accentuate faults. These have frequently been combined with reflection amplitude displays to show bright spots bounded by faults, which indicate potential reservoirs. Coherency can also emphasize stratigraphic features such as channel boundaries, which are also discontinuities in the reflection amplitude field. A typical stratigraphic workflow begins with the interpreter scanning the 3D Previous HitseismicNext Hit Previous HitdataNext Hit set in section and plan view to look for stratigraphic features. Figure 1 shows a shallow time slice of reflection amplitude Previous HitdataNext Hit with indications of channels. Figure 2 shows the same time slice with a blend of amplitude and coherence Previous HitdataNext Hit. It is immediately evident that the channels are more clearly displayed in the combined attribute Previous HitdisplayNext Hit.

Flattened and Structural Voxel Displays

Once stratigraphic features have been spotted, the interpreter needs to discover their full extent in the Previous HitdataNext Hit set. Features are unlikely to lie flat on a particular time or depth slice. Channels may have an almost flat expression at the time of deposition but will typically occupy a depth or time range. Other features such as dunes, reefs, or channel fan complexes were not flat at the time of deposition. Interpreters may examine a thick slab of Previous HitseismicNext Hit Previous HitdataNext Hit by making some amplitude values transparent. Interpreters may also pick a structural horizon and then flatten the volume. A flattened slab can then be examined using transparency. Figure 3 shows a flattened slab where the positive

Figure 1. Time slice of amplitude Previous HitdataNext Hit showing channels.

 

Figure 2. Time slice that is a blend of amplitude and coherence Previous HitdataTop showing channels.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24