碳酸盐岩发育区地震成像技术研究及应用效果

针对川东北地区碳酸盐岩高度发育,地层隆凹相间,各种波场交叉叠置,层间接触关系复杂,以及静校正问题、高陡构造及速度变化快等影响因素突出的特点,通过分析地表因素、有效波频率、静校正量及膏岩层效应对地震资料品质和成像的影响,研究和开发出三维折射波静校正以及构造建模层速度约束偏移成像等一系列处理技术,消除了众多因素对地震成像的影响,并在宣汉达县地区得到良好的应用效果,为普光特大气田的大规模开发奠定了基础。

Research and Application of Seismic Imaging Technology to Carbonate Rock Area

Seismic imaging in Northeast Sichuan is greatly influenced by the widely distributional carbonate,strata juxtaposition with swelling and concaving,superimposition and connection between different wave fields,complex interlayer contact conditions,static corrections,high and steep structure,as well as rapid change of seismic velocity in the area.By analyzing the effect of surface factors,effective wave frequency,amount of static correction,and gypsum bed effectiveness on the quality and imaging of seismic data,a series of processing technologies,such as the 3D refraction static correction technology and the migration imaging technology constrained by the velocity of structural modeling layers,have been developed and they clear up the unfavorable influences on seismic imaging.The technologies have been applied to the Xuanhan-Daxian area of Northeast Sichuan and good results have been achieved,laying a solid foundation for the large-scale development of super-large Puguang gasfield.