Abstract

Velocity is one of the fundamental data obtained from seismic and it is the direct behavior of the solids and fluids in lithosphere. Here we present an analysis of the derivative gradient of seismic velocity which can help identify the featured boundary of favorable petroleum accmulations such as sedimentary facies boundary, faults, and flow unit edges. The derivative gradient can be calculated both horizontally and vertically, thus it can help discriminate favorable targets in three-dimensional. We find the application of derivative gradient to detect or enhance edge is relatively mature in gravity and geomagnetic analysis but rarely mentioned in seismic nor in petroleum exploration. We believe we can make better use of the seismic velocity data by this means as it is quite efficient in pinpointing the favorable petroleum targets in subsurface with precisions of tens-of-meter scale, depending on the horizontal resolution of seismic survey.