P- and S-wave multi-attribute analysis for Morrow A sandstone detection

The Upper Morrow sandstone reservoir in the western Anadarko Basin is a major oil-producing reservoir. These sandstones have plagued operators and investigators alike because of their irregular distribution. It is difficult to detect these thin, discontinuous reservoir sandstones using P-wave datasets because of insufficient acoustic impedance contrast between the Morrow sandstone and surrounding shale. But the contrast in rigidity between the Morrow sandstone and surrounding shale causes a strong seismic expression on the shear wave data. Morrow sandstone reservoir is a good example to show how S-wave data can help to improve the detection of reservoirs with low acoustic impedance contrast. The P, SV and SH stacks obtained after processing multi-component seismic data are interpreted. The SV and SH stacks are from S-wave data obtained from horizontal source and horizontal receiver recording. The attributes extracted from the P, SV and SH stacks are correlated with the Morrow A sandstone thickness obtained from well logs. The SV- and SH-wave attributes give better prediction of Morrow A sandstone thickness compared to P-wave attributes. The multi-attribute analysis provides better correlation with sandstone thickness compared to a single attribute. The multi-attribute map was used to predict seismic-guided isopach map using cokriging.