Case study of offshore high resolution seismology

High-resolution seismic data was applied to evaluate DF1-1 gas field for gas exploration in Yinggehai basin. The high-resolution seismic sections showed the water channels clearly, which truncated the gas reservoir, and a correct geological model of the gas field was given. The reservoir description given by the high-resolution seismic data determined the gas/water contact, the thickness and porosity of the reservoir. All of this reduced the number of evaluation wells. With conventional seismic a dry hole was drilled on LD8-1 anticline, but the second well got high rate of gas production after shooting high-resolution seism, on which there were both bright-spots and flat-spots. Practice proved that low frequency was more important than high frequency for high-resolution seismic. Seismic impedance section presented subsurface geological condition more directly and clearly than seismic migration section, so interpretation and reservoir characterization using the seismic impedance data would obtain better result.