Building the surfaces

The creation of each surface was a two-step interactive process. In the first step events are picked on orthogonal vertical slices of the data using the modules Pick Geom and Create Line as is explained in Clapp (1994) The resulting 3-D field was then sent to the Project Manager module and a GOCAD surface was created using the Create Surface option. These steps were repeated for each surface constructed. Figure 3 shows the AVS network used to construct the GOCAD model.

 

Surfnet
Figure 3 AVS network for picking events and building surfaces from a seismic dataset.

Modules browser cm, slicer cm and gain cm are presented in Biondi and van Trier (1993); these remote modules take advantage of the data handling and computational capabilities of SEP's CM-5 allowing the management of large 3-D seismic surveys. The slice output by those modules, is passed to the local workstation to be visualized in a local Geometry viewer scene where events are picked. The Pick Geom and Create line are local modules, that is, they run on the local workstation. Pick Geom determines the location in modeling coordinates of a picked point in the Geometry Viewer. The location of the picked point, in this case from a slice of a 3-D cube, is sent to the Create line module. The Create Line module connects successively picked points to a form a line. Once the seismic event corresponding to a single reflector has been picked on a given slice, the New Line widget is selected in the Create line module. Another slice of the data is displayed using the Slicer widget in Slicer cm , and process is repeated until all the lines corresponding to the surface have been defined. Figure 4 shows the creation process after several lines have been selected. Finally, the Write it widget in the Create line module is selected to send the picked lines to the Project Manager module.

 

3Dpick
Figure 4 Geometry viewer scene with picked lines, a surface and a seismic data slice.