渤海湾X油田气云区地震资料关键处理技术研究

Key processing technologies of seismic data for a gas cloud area in the X oilfield,Bohai Bay Basin

受郯庐断裂带活动影响,渤海湾盆地X油田气云区广泛发育。地震资料受气云影响严重,在油田主体区地震成像效果较差,无法准确描述构造和储层特征。在现有纵波资料的基础上,开展了气云区关键处理技术研究,包括Q值层析反演气云区能量吸收衰减补偿技术、潜波层析反演浅层速度建模技术等,有效解决了气云区地震能量吸收衰减严重和浅层难以实现高精度速度建模的问题,同时结合其它配套处理技术,如匹配追踪插值数据规则化技术、水层多次波压制+广义地表多次波压制技术,形成有针对性的有效处理技术流程。本工区处理结果表明,该处理流程明显提高了气云区地震资料的成像质量。

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.