CROSS-WELL REFLECTION IMAGING AT THE VERKHNEKAMSKOE POTASSIUM SALT DEPOSIT
A.V. Chugaev, I.A. Sanfirov, M.V. Tarantin
Mining Institute, Ural Branch of the Russian Academy of Sciences, Perm, Russia
Keywords: Seismic well survey, cross-well seismic survey, depth seismic section, reflected waves, cross-well tomography, common depth point, migration of reflected waves
Abstract
We propose a technique for the extended processing of cross-well seismic data for reflection imaging. Based on the analysis of the wave field and synthetic modeling, a graph for processing cross-well data is developed to separate the reflections in the presence of the boundary of a sharp change in the velocity of elastic waves. The migration of the reflection waves from the time scale to the depth one is performed by solving a forward problem for each source-receiver pair. As a result, the position of the reflection points is calculated, after which all traces are stacked based on the binning grid. The input information for performing the migration and solving a forward problem is the velocity characteristic of the massif, which is calculated using traveltime tomography on direct body waves obtained from the same data set of cross-well survey and vertical seismic profiling. The resulted depth seismic section has a much higher resolution than that of vertical seismic profiling and ground-based shallow seismic studies. This opens up the possibility of identifying various small-sized natural or technogenic objects in the interwell space. Practical implementation was carried out at the Verkhnekamskoe potassium salt deposit.
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