Changes

After scanning, detailed mapping begins by working outward from a point where geological information exists, preferably a well location with a synthetic seismogram. The horizons selected for mapping and observed fault cuts are correlated from the well to the seismic. The interpreter then begins to pick these same events away from the well on the seismic, being careful to tie at all other well locations.

After scanning, detailed mapping begins by working outward from a point where geological information exists, preferably a well location with a synthetic seismogram. The horizons selected for mapping and observed fault cuts are correlated from the well to the seismic. The interpreter then begins to pick these same events away from the well on the seismic, being careful to tie at all other well locations.

Critical to the interpretation process is comparing how horizons and faults tie at line intersections. Significant effort is expended correcting misties of faults, horizons, and sequence boundaries at every line intersection. In this regard, closing the interpretation in loops around the seismic grid is a particularly effective technique. On a workstation, a quick way to check for misties is a contour map. Misties will be evident by groups of unreasonable contours. In addition, workstations can be very helpful for working out the misties among varying vintages of two-dimensional data by applying time and phase shifts automatically.

Critical to the interpretation process is comparing how horizons and faults tie at line intersections. Significant effort is expended correcting misties of faults, horizons, and sequence boundaries at every line intersection. In this regard, closing the interpretation in loops around the seismic grid is a particularly effective technique. On a workstation, a quick way to check for misties is a contour map. Misties will be evident by groups of unreasonable contours. In addition, workstations can be very helpful for working out the misties among varying vintages of two-dimensional data by applying time and phase shifts automatically 9See [[Seismic data - mapping with two-dimensional data]]}.

Tying all lines in both 2-D and 3-D data sets is the only way to reliably construct a three-dimensional model of the subsurface using two-dimensional images. Tying around data loops is also the best way to correlate from fault block to fault block. Otherwise, faults must be jumped using reflection character, sequence analysis, or additional well control.

Tying all lines in both 2-D and 3-D data sets is the only way to reliably construct a three-dimensional model of the subsurface using two-dimensional images. Tying around data loops is also the best way to correlate from fault block to fault block. Otherwise, faults must be jumped using reflection character, sequence analysis, or additional well control.