关键词: desert, high frequency attenuation, resolution, formation quality factor, near-surface Q model, sub-surface Q model, one-step Q compensation

Abstract: The hinterland of Junggar Basin is covered by desert. The majority of middle-high frequency energy in seismic reflection waves is absorbed by near-surface sand dunes. To improve seismic data resolution, the paper proposes a method to build an integrated near-surface and subsurface, pre-stack Q model. Firstly, the method calculates the relative near-surface Q field at shot and receiver points with simplified spectral ratio based on amplitude and main frequency of seismic data and seismic travel time on the surface; then uses formation quality factors at near-surface shot-receiver points to modify average sub-surface Q model and establishes a pre-stack average Q model containing near-surface variations, which could further compensate seismic data of one-step pre-stack Q model. The seismic data resolution obtained from the model in the desert area is better than that obtained from conventional subsurface Q compensation method and deconvolution method. The results of synthetic seismogram calibration and pre-stack inversion are better than those of conventional methods as well. Therefore, the model has good prospects for application.

Key words: desert, high frequency attenuation, resolution, formation quality factor, near-surface Q model, sub-surface Q model, one-step Q compensation