Offset vector tile domain wide-azimuth prestack seismic interpretation methods and applications

Abstract

The offset vector tile (OVT) is a special prestack seismic gather type, and OVT technology is a seismic processing technology suitable for wide-azimuth seismic (WAZ) exploration. Because current WAZ interpretation is not yet mature and because of the lack of key techniques and tools for OVT-domain seismic interpretation, abundant offset and azimuth information possessed in the OVT gathers has not been fully used. To take full advantage of the OVT gathers to achieve more accurate geologic, reservoir, and fluid information, we have developed an OVT-domain wide-azimuth prestack seismic interpretation technology and a typical workflow. The OVT-domain wide-azimuth prestack seismic interpretation technology is composed of five key prestack analysis and interpretation techniques focused on OVT gathers: (1) sensitive offset and azimuth analysis for choosing their sensitive offset and azimuth ranges, (2) template-based OVT gather optimization for improving their signal-to-noise ratio and quality, (3) multiscale and multiazimuth attribute analysis, (4) OVT domain amplitude versus incidence angle analysis, and (5) azimuthal anisotropy analysis. These technologies are used to extract seismic attributes that vary with offset and/or azimuth from OVT gathers facing on reservoir characterization, fluid detection, and fracture prediction. These technologies can form an OVT-domain prestack seismic interpretation workflow.

Methods for the Geophysical Exploration and Sustainable Utilisation of Coalbed Methane Resources in Abandoned Mines of Shanxi, China

“…By designing a wide-angle observation system, highquality seismic data volumes were effectively collected. After processing with techniques such as offset vector slices (OVT), a five-dimensional pre-stack seismic trace set in the OVT data domain was obtained, laying the data foundation for the interpretation of five-dimensional seismic data [34,35]. This method has rich azimuth information and comprehensively utilizes multiple attributes to detect changes in underground fractures and lithology with changes in azimuth, which significantly increases seismic exploration accuracy and improves seismic imaging effects.…”

Wide-Azimuth Seismic Processing Method for Shale Oil Exploration

“…Secondly, according to the above method, several cross array gathers are extracted from the observation system of the whole work area, and the OVT vector tiles with the same coordinates are extracted, which are arranged according to the corresponding Inline number and Crossline number to form the OVT gather of the whole area, the OVT gather is a single coverage data volume, similar to a conventional migration data volume. The data volume contains 3D spatial coordinates, offset, azimuth and other information, and is a five dimensional data volume (Williams et al 2002;Scott 2009;Zhan 2018).…”