Abstract：The seismic reflection near the critical angle is recognized as a property of reflection seismology.The near critical reflection and supercritical reflection were seldom recorded because people usually used short seismic spread in the past. Long seismic spread was used in Erlian area in 1987; therefore, obvious supercritical reflection informations, wideangle reflections, occur at shallow layers of almost all seismic sections. Much more noises are recorded on the near traces(offsets 0~1500m) than on far traces. Effective reflection signals on near-offset traces are almost submerged in noises. In the light of the phenomenon that wide-angle reflection has high amplitude, we extracted wide-angle reflection informations from the seismic data in Erlian area. The method used is simple. As a result, we acquired the high S/N sections whose seismic continuity is quite good. The sections are useful in practice.
