Application of frequency-broadening processing technique in exploration and development of Daniudi gas-field

The reservoir in Daniudi gas field is characteristics of low porosity, low permeability and strong non-uniformity, and surface is covered by desert and semi-desert, developing coal seam that produces serious screen phenomenon, which resulted in low S/N ratio of seismic data and unclear feature of seismic response to sand body, making the reservoir prediction very difficult. For that reason, the frequency-broadening processing technique is used in seismic data processing in the region. Starting from the principle of frequency-broadening processing technique, the paper analyzed the feature of frequency-broadening processing, briefly introduced the selection of two important parameters in frequency-broadening processing flow. The method achieved significant result after practical application in Daniudi gas field, which is in the followings: 1, improvement of dominant frequency and broadening the frequency band; 2, the geologic meaning of horizons of seismic reflections is more meaningful and seismic information is more abundant; 3, the match of synthetic seismogram with seismic data is better; 4, the reflected seismic attributes are finer. The application results showed that the method can better provide the reliable basic data for inversion of thin and alternative reservoir and description of gas reservoir. The suggestion is that the usage of the method is better in the region where the S/N ratio is as high as possible. In the Daniudi gas field, the method is more suitable to Shanxi Formation and Taiyuan Formation and unsuitable to Lower Shihezi Formation.