Application of an integrated wave-equation datuming scheme to overthrust data: A case history from the Chinese foothills

摘要

An integrated wave-equation datuming scheme improvesthe imaging quality of seismic data from overthrust areas. Itcan be regarded as integrated because upward-layer replace-ment is included. In this scheme, data are downward contin-ued to a nonplanar datum (such as the base of the weatheringlayer), followed by upward continuation from the nonplanardatum to a final planar datum using a one-way extrapolator.When compared with a Kirchhoff integral, this method candeal better with the strong lateral velocity variation within thenear surface. After a test on synthetic data, the scheme is ap-plied successfully to real 2D overthrust data acquired in theQi-Lian foothills, western China. Compared with results us-ing static corrections, integrated wave-equation datuming re-sults lead to better reconstruction of the diffractions and re-flections, more reliable migration-velocity analyses, andstronger stack and final depth images.