EFFECTS OF SILL (TRAPS) ON WAVE FIELDS IN OBSERVATIONS BY THE MULTIPLE REFLECTION METHOD

The Tunguska syncline is considered as one of the most promising oil and gas regions. However, it is difficult to resolve structural problems there because of the very complicated seismogeological conditions, especially in the upper part of the section. At depths down to 1 km there are sills of various shapes which adversely affect the passage of useful waves and produce multiple reflections. Less is known about the effects of local traps of restricted extent in the upper part of the section on the kinematic and dynamic parameters of the reflections from the underlying boundaries as recorded by the multiple reflection method (MRM). However, results from theoretical, model, and experimental studies indicate that local inhomogeneities in the overlying beds play an important part in producing the reflected-wave fields. The Vanavar area is studied by using mathematical simulation to examine the distorting action of local traps on the reflected-wave kinematic parameters. 6 references, 2 figures.