TRUE-AMPLITUDE LAYER-STRIPPING IN FRACTURED MEDIA

摘要

Method for determining fracture orientation and fracture intensity in multiple fractured layers in the subsurface in a layer-stripping manner. Multi-component, multi-azimuth seismic data are required (31), from which the horizontal, primarily converted wave, components are selected, and these data are further reduced by selecting only the data for which the survey azimuths are either parallel or perpendicular to the general fracture strike (33). If the general fracture trend is unknown, such selective data may be determined by an azimuth-offset scanning process. Layer stripping is performed on azimuth/offset stacks (42) to produce fracture parameter maps (43). All offsets are stacked in those azimuths that produce consistent fracture parameter maps (44), then layer stripping is performed (45) on the stacks to produce final fracture orientation and S-wave time difference maps (46). These maps can be used to produce true amplitude fast and slow S-waves (56).