碳酸盐岩深层走滑断裂成像技术

Seismic Imaging Technology for Deep Strike⁃Slip Faults in Carbonate Reservoirs

塔里木盆地顺北地区奥陶系碳酸盐岩储集层埋藏深,地震波吸收衰减严重,寒武系—奥陶系深层走滑断裂形成的绕射波场能量弱,成像难度大。针对研究区深层走滑断裂的成像需求,从深层走滑断裂低频弱振幅的地震响应特征出发,在保护低频信号下的噪声压制和低频信号增强的子波一致性处理的基础上,结合断裂控制约束速度建模与层析速度反演技术,并利用宽频逆时偏移成像技术,有效提高了塔里木盆地顺北地区沙漠地表覆盖下深层走滑断裂的成像质量,从而降低勘探风险,为圈闭落实和井位部署提供可靠资料。

Seismic wave reflected from the deeply buried Ordovician carbonate reservoirs in Shunbei area of Tarim basin is absorbed and attenuated seriously,and the energy of the seismic wave field diffracted from the deep strike⁃slip faults in the Ordovician-Cambrian forma⁃tions is weak,making it difficult to get accurate seismic image.To improve the quality of seismic image,we analyzed the seismic responses characterized by low frequency and weak amplitude,then suppressed noises while protecting low⁃frequency signals and carried out wavelet consistency processing,and finally applied fault⁃controlled velocity modeling,tomographic velocity inversion and broadband inverse time migration imaging technologies to improve the seismic imaging quality of the deep strike⁃slip faults under the desert in the Shunbei area of Tarim basin.The result is helpful to reduce exploration risks and provides reliable data for trap implementation and well allocation.