Abstract: A gas cloud area is widely developed in the X oilfield of the Bohai Bay Basin owing to the influence of the Tan-Lu fault zone.Structure imaging quality is poor within the gas cloud area, which introduces great challenges in structure delineation or reservoir prediction.To overcome this problem, the paper proposes key processing technologies of seismic data for the gas cloud area.Q tomography was adopted to compensate for the seismic energy absorbed by the gas cloud during depth migration by deriving a 3D reliable space variant Q model, which is based on the attenuated travel-time tomography applied on prestack seismic data.Diving-wave refraction tomography (DWT) was employed to produce a reliable near-surface velocity model for the seismic data with low signal-to-noise ratio from the gas cloud area, to obtain an initial model for reflection tomography in mid-deep seismic data processing.Moreover, this paper introduces other technologies to complete the process flow, namely, matching pursuit Fourier interpolation (MPFI) for data regularization and the combination of deterministic water-layer demultiple (DWD) and general surface multiple prediction (GSMP) for multiple attenuations.The processing results of the field data in the X oilfield of the Bohai bay Basin showed that the proposed processing technologies could help improve the structure imaging in the gas cloud area.