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 (see [[Seismic data - mapping with two-dimensional data]]).

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.

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.

* Seismic velocity maps for lithology determination or depth conversion

* Seismic velocity maps for lithology determination or depth conversion

In addition, many combinations of these maps can be made, such as seismic amplitude plotted on top of structure. The only limitations in constructing these maps are the imagination and skill of the interpreter (see [[Mapping with two-dimensional seismic data]]).

In addition, many combinations of these maps can be made, such as seismic amplitude plotted on top of structure. The only limitations in constructing these maps are the imagination and skill of the interpreter.

The overall aim of seismic interpretation is to aid in constructing the most accurate earth model or reservoir description possible. This can best be accomplished when the seismic data are merged with petrophysical, geological, and engineering databases. While the process of interpreting seismic data is basically the same on paper or in a workstation environment, the workstation offers advantages in data management, manipulation, and display and it allows for a more convenient integration of other data types.

The overall aim of seismic interpretation is to aid in constructing the most accurate earth model or reservoir description possible. This can best be accomplished when the seismic data are merged with petrophysical, geological, and engineering databases. While the process of interpreting seismic data is basically the same on paper or in a workstation environment, the workstation offers advantages in data management, manipulation, and display and it allows for a more convenient integration of other data types.