Seismic resolution over coal seams: a numerical study
Processing tool like migration is rarely applied to high resolution shallow coal seismic data. The improvement of stacked section by using migration is so far only marginal. In addition, it takes tong computing time to perform migration on PC based system commonly used for day-to-day shallow high resolution seismic data processing. With the advent of powerful and inexpensive workstation, migration is carried out on post stack as well as pre stack data. The present study is an example of migration technique applied to zero-offset time sections generated for three different geological models. The geological models incorporate coalseam discontinuities like fault, fold and feeder dyke commonly encountered in the coal bearing formations of eastern India. In order to select a suitable migration scheme, both finite-difference depth migration and frequency wavenumber (f-k) phase shift time-migration are applied to the zero-offset data generated for these models. Depth migration scheme has significantly improved the imaging conditions compared to the f-k phase shift time-migration. Besides, the depth migration restored the lateral continuity of the fault and delineated the small scale structural features clearly in the case of feeder dyke and fold.
Bibliogr. 6 poz.