*Adapted from oral presentation at AAPG Annual Convention, San Antonio, Texas, April 20-23

¹dGB-USA, Sugar Land, TX (mailto:[email protected])

Abstract

Seismic data is one of the important sources of sequence stratigraphic information. Despite (or due to) the richness of sequence stratigraphic information in seismic data, it is difficult to isolate, map, and interpret system tracts in 3D seismic data. However, once mapped in a Wheeler diagram, interpretation of system tracts, sea-level change, and shoreline shifts becomes much easier, ultimately facilitating the identification of source rock, reservoir-seal-couplets, and stratigraphic traps.

We will present a workflow illustrated with case study examples in which we semi-automatic construct a Wheeler-type diagram from seismic data and use a dual seismic/Wheeler display for system tract interpretation. Finally, we show how detailed stratigraphic features, such as channels and fans, can be mapped with ease in 3D Wheeler space.

The procedure depends on the accurate determination of the dip of seismic events, using a method called dip-steering. Subsequent step is the automated data driven tracking of chrono-stratigraphic horizons using the calculated dips from the previous step. The tracking is designed to honor horizon truncations at unconformable boundaries. Using the chrono-stratigraphy, we transform the data from the seismic domain to the Wheeler domain, including creation of hiatuses in areas of non-deposition and erosion. A simultaneous display of amplitude data (seismic character) and chrono-stratigraphy in the seismic domain and depositional trends in the Wheeler domain allows an easy and accurate interpretation of the system tracts and depositional style.

Using the information obtained in the previous step we build a 3D model-driven chrono-stratigraphy, again honoring unconformities. We use this to create a 3D Wheeler space, in which time slices are equivalent to horizons slices in the seismic domain.

uAbstract uFigures uConclusions   uAbstract uFigures uConclusions

Selected Figures   Location map of case study. Chrono-stratigraphy illustrated on seismic profile. Seismic domain (left) and Wheeler domain (right). Seismic Wheeler diagram.   System tract interpretation. Geomorphology — composite similarity + segmentation. Conclusions Examples showing integration latest seismic interpretation techniques with well logs and regional geology. Comprehensive analysis leading to a geological concept. Interpretation analog. Future analysis will expand and fine-tune interpretations. Return to top