Oil & Natural Gas Projects
Exploration and Production Technologies
Elastic-Wavefield Seismic Stratigraphy: A New Seismic Imaging Technology
The objective of this project is to demonstrate the value of elastic-wavefield
seismic stratigraphy, a new seismic interpretation science based on the principles
- All modes of an elastic wavefield have equal value for studying subsurface
- One wave mode of a multicomponent (i.e., elastic) seismic wavefield often
reveals depositional sequences and depositional facies across a stratigraphic
interval that cannot be detected with the other modes of that wavefield.
Bureau of Economic Geology
University of Texas at Austin
Fasken Oil and Ranch
Examples have been documented in which shear (S)-wave data provide geologic
information that cannot be extracted from the companion compressional (P)-wave
data. Examples also have been documented in which P-wave data provide information
that is not present in the companion S-wave data.
The principal benefit of this research is that it introduces a new seismic technology
that will aid in the search for subtle stratigraphic trap oil reservoirs. If
a subsurface structural description of major Earth layers is the only information
that is needed to exploit a prospect, that information can be provided by P-wave
seismic data alone. In contrast, significantly more stratigraphic information
can be extracted from multicomponent (elastic wavefield) seismic data than from
single-component P-wave data.
Seismic stratigraphy was introduced by Exxon as a formal seismic interpretation
science in 1975-77. For decades, the science was limited to single-component
P-wave seismic data. This project is expanding the science to multicomponent
seismic data and showing how these expanded concepts improve the detection of
In Year 1, the study focused on West Texas 3-component, 3-D seismic data and
demonstrated how this new science improves detection of carbonate stratigraphic
traps. In Year 2, the research moved to a 3,000 square-mile area of 4-component
(4-C), 2-D seismic data coverage across the northern shelf of the Gulf of Mexico
and showed that new elastic-wavefield concepts allowed critical new insights
into the distribution of stratigraphic traps in sand/shale sequences . In Year
3, the study concentrates on applying elastic-wavefield interpretation concepts
to 9-component, 3-D seismic data across the Williston Basin. In each study area,
the principal problem that is addressed is to improve the detection of stratigraphic
Among the project highlights:
- 9-C, 3-D seismic data from the Williston Basin have been interpreted. The research team is now documenting distinctions and similarities between P and S seismic sequences and seismic facies observed in these data.
- The greatest differences between P and S seismic sequences and facies observed to date occur in deepwater, near-seafloor strata. Several examples are being documented.
- A numerical study of P-P, P-S, and S-S reflectivities is being done to define key petrophysical properties that cause these modes to exhibit different reflection behavior for identical geological layering.
Current Status (June 2006)
The project is on schedule and midway through its third and final year. The research team is now beginning to prepare the final project report, documenting key principles and research findings, and thinking about publications and public work-shops. Improved S-wave volumes (fast-S and slow-S) across the 9-C, 3-D Williston Basin survey will be delivered to the research team in late January. If there are significant improvements or image variations in this second processing effort compared with the volumes that have already been studied, a second interpretation will be done to develop additional comparisons of P and S seismic sequences and facies.
Project Start: August 1, 2003
Project End: July 31, 2006
Anticipated DOE Contribution: $740,573
Performer Contribution: $189,000 (20.3% of total)
NETL: Purna Halder (email@example.com or 918-699-2084)
U. of Texas: Bob Hardage (firstname.lastname@example.org or 512-471-0300
Six quarterly reports and one continuation report have been delivered to DOE.
Hardage et al., Defining P-wave and S-wave stratal surfaces with 9-C VSPs,
The Leading Edge, V. 22, 2003, pp. 720-729.
Fomel et al., Multicomponent seismic data registration for subsurface characterization
in the shallow Gulf of Mexico, Offshore Technology Conference, 2003, Houston,
Murray et al., Interpreting multicomponent seismic data in the Gulf of Mexico,
Offshore Technology Conference, 2003, Houston, TX.
DeAngelo et al., Depth registration of P and C seismic data for shallow marine
sediment characterization, The Leading Edge, V. 22, pp. 96-105.
Hardage and Aluka, Elastic-wavefield seismic stratigraphy, scheduled for the
January 2006 issue of AAPG Explorer.
Hardage and Aluka, Depth registration of P and S data, scheduled for the February
2006 of the AAPG Explorer.
Maps of P-P and P-SV amplitude-based seismic facies (top) across a carbonate
interval of West Texas and vertical sections through these P-P and P-SV data
volumes along inline 67 (bottom). A unique P-SV amplitude facies follows the
trend of productive stratigraphic-trap wells (right); the P-P amplitude facies
does not (left).
Comparison of deep, depth-equivalent, P-P and P-SV data windows, Gulf of Mexico.
These data are a classic example of the principle of elastic-wavefield seismic
stratigraphy in that the sequence geometry defined by P-SV features 1 and 2
differs from the P-P geometry.