Using Continuous Wavelet Transform and Short Time Fourier Transform as Spectral Decomposition Methods to Detect of Stratigraphic Channel in One of the Iranian South-West Oil Fields

Abstract

Classical seismic methods for characterization of hydrocarbon reservoirs have been used for decades. Stratigraphic events affect seismic sections in addition to structural events. Today the necessity of usage of seismic sections to determine reservoir extension and stratigraphic characteristics is increasing. Conventional seismic sections cannot display most of the   important events in reservoir studies. The study of frequency content of seismic sections can provide better understanding to geoscientists, as well as interpreters in the field of petroleum engineering studies. An isofrequency process is a powerful tool in terms of reservoir imaging. One of the methods that provides isofrequency slice is Spectral Decomposition (SD).

SD is a comprehensive method that eliminates most of limitations encountered in seismic data to reveal geological information. SD provides continuous analysis of amplitude, frequency, phase, and energy spectrum. Therefore, SD is applied to obtain an amplitude spectrum of frequency content of seismic trace which is attributed to the temporal center of the sample trace, so higher frequency resolution is obtained at lower frequencies and higher time resolution at higher frequencies.

 In this paper, Short Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) as SD methods were used in order to detect stratigraphic channel at one of the Iranian South-West oil fields for which it has the potential to be considered as a reservoir.