陆丰凹陷复杂断裂带双方位地震资料联合成像技术研究

Research on joint tomographic of the complex fault zone in lufeng sag on dual-azimuth seismic data

陆丰凹陷A洼工区面积小,油气储量大,原有采集地震资料分辨率低,多次重处理之后目的层接触关系难以确定,复杂断裂带及陡倾角基底成像模糊,难以满足勘探需要。因此在该区进行了二次三维地震资料采集,采集方位正交。针对同一区块不同方位采集的三维地震资料,分析不同方位地震资料的差异性,针对性的提出使用断层约束的双方位资料联合层析反演技术来求取精度更高的速度场,通过TTI各向异性中的倾角和方位角属性解决不同方位资料陡倾角地层的同相轴错动,提高偏移归位精度,更好地实现双方位资料的融合成像,古近系陡倾角地层成像品质提升明显,地层连续性、信噪比更高,为后续目标评价工作提供可靠的基础资料。

The working area of A hollow in Lufeng Sag is small,and the oil-gas reserves are rich.The resolution of the original seismic data is low,and after multiple reprocessing,the contact relationship of the target layer is difficult to determine.The imaging of complex fault zones and the high-dip-angle basement is fuzzy,which is challenging to meet the exploration needs.Therefore,the second three-dimensional seismic data acquisition is carried out in this area,and the acquisition azimuth is orthogonal.Given the three-dimensional seismic data collected in different directions in the same block,the difference of seismic data in different directions is analyzed,and the combined tomography inversion technology with fault constraint is proposed to obtain the velocity field with higher accuracy.Through the dip angle and azimuth attribute of TTI anisotropy,the coaxial dislocation of steep dip strata in different azimuth data is solved,the migration and positioning accuracy is improved,and the fusion imaging of two-dimensional data is better realized.The imaging quality of Paleogene steep dip strata is improved,stratigraphic continui-ties、the signal to-noise ratio is higher,which provides reliable basic data for subsequent geological evaluation.