The time-frequency analysis for delineating the thickness distribution of tight sandstones

The Shan179 prospect in the Sulige gas field of Ordos Basin (onshore of western China) was proved by one exploratory well in 2007. The discovery well has produced gas from tight sandstone reservoirs of the Xiashihezi Formation of Lower Permian. The principal targets of drilling, completion, and production are the thick massive sands at point bars. In this study, we acquired 3-D seismic data, and applied data from 27 vertical wells to show the potential of applying a time-frequency analysis to map the thickness distribution of the tight reservoir sandstones. The continuous wavelet transform with the generalized Morse wavelets provides a powerful implement to delineate the thickness distribution. The study results have revealed the geological interpretation of the producing reservoirs for the well placement.