The influence of near-surface hard rock environments on reverse time migration seismic imaging

Summary Imaging seismic waves beneath near surface hard rock have a complex challenge. The seismic waves will be scattered. Many seismic wave imaging targets, for example, hydrocarbon potentials, are under near surface hard rock environment such as: under reef or vulcanic rock. Reflection seismic method, however, has some constraints to obtain good images beneath near surface hard rock environment. Irregularities of volcanic and carbonates rock create scattering and nonlinearity in the reflected wave. Then, the reflected wave propagates in caustics or non-linear paths. Therefore, many seismic migration methods fail in providing accurate image beneath near surface hard rock environment. We present imaging cases beneath hard rock environment using reverse time migration based on inverse scattering. The migration uses individual shot record data and migrated by the reverse time migration of Born’s approximation. The inverse scattering reverse time integrates the whole individual migrated shot record data sequentially. The results show the layers and faults beneath hard rock environment can be revealed clearly. The longer far offset of split spread configuration produce better quality image than shorter far offset of one. The seismic imaging beneath near surface hard rock environment are useful for unlocking the new potential area beneath near surface hard rocks.