Apparatus and method for accurately determining the location of events

Abstract

An operator sitting at a workstation views, on a display, a multitude of seismic traces having one or more horizons indicated therein by a plurality of sets of events (such as peaks or troughs or zero crossings) on the seismic traces. The operator uses a mouse to draw a line from left to right across a plurality of seismic traces being displayed on the workstation display screen. At this point, the line does not lie on the events (such as the peaks) of the seismic traces. Therefore, the line does not yet represent a horizon in an earth formation. The operator presses a key on the keyboard of the workstation. In response to the pressing of this key, the workstation processor executes a 'snapper software' in accordance with the present invention. When the snapper software of the present invention is executed, the line, previously drawn by the operator across the seismic traces on the workstation display screen, moves from one location, not corresponding to the events (such as the peaks) of the seismic traces, to another location, corresponding to the events (such as the peaks) of the seismic traces. When the line moves to said another location on the screen display, the line now lies directly on a set of events (such as peaks) of the seismic traces which underlie the line. Now, the line does accurately represent a horizon in an earth formation. The snapper software of this invention can determine the peaks, the troughs, and the zero crossings of the seismic traces. As a result, the horizon depicted by the snapped line on the workstation screen display is accurately represented.