论文详情
近地表介质吸收衰减补偿是高分辨率地震勘探的关键,其核心是建立高精度的近地表Q模型。针对常规衰减补偿处理中近地表Q模型建立方法存在的不足,提出一种基于信息融合的近地表介质Q估计方法以及稳定的反Q滤波处理技术。首先采用多井微测井和地面联合的新型观测系统,综合折射波与透射波多种信息进行调查点精细Q估计,然后基于炮检点初至波数据采用统计反演估算全区相对Q值,并运用信息融合策略,利用调查点精细Q值约束相对Q值,整合建立精确的近地表Q模型。最后用于反Q滤波,以实现近地表衰减补偿,提高地震资料分辨率。在塔北浮土区的实际应用中得到了可靠的近地表Q模型,通过叠前补偿处理,目的层的地震反射波频带展宽超过20 Hz,反射波振幅和频率特征得到了改善,储层信息更加丰富,地震资料分辨率也得到了提高。
关键词：近地表;Q估计;吸收调查;微测井;衰减补偿
Absorption attenuation compensation in near-surface media is highly relevant to high-resolution seismic exploration.Its key is to build high-precision near-surface Q model.This paper proposes a Q value estimation method for near-surface media based on information integration and a stable anti Q filter processing technique.First,a new type of observation system with joint multi-well uphole survey and ground survey is introduced,to estimate the fine Q value of the investigation points by combining refraction and transmission waves.Second,the relative Q value of the whole region is estimated by statistical inversion,which is based on the first arrival data from the shooting.After that,the precise Q value and the relative Q value are integrated to set up an accurate near-surface Q model.Finally,an inverse Q filter is used to compensate the near-surface attenuation and improve the resolution of seismic data.Tests of field data in the northern Tahe oilfield showed that the method could help to establish the reliable near-surface Q model,and also broaden the frequency band of target reflectors of more than 20 Hz by using prestack attenuation compensation.In addition,both amplitude and frequency characteristics of reflected wave were improved to acquire rich reservoir information and high resolution.
国家科技重大专项(2017ZX05005-004-008)资助。