地震波逆时偏移中的层位校正与去噪方法  

Imaging Horizon Correction and Denoising Method in Seismic Wave Reverse-time Migration

作　　者：牟海波[1] 何兵寿[1] 

机构地区：[1]中国海洋大学,海底科学与探测技术教育部重点实验室,山东青岛266100

出　　处：《中国煤炭地质》2016年第4期71-75,共5页Coal Geology of China

基　　金：国家自然科学基金项目(编号:41174087,41204089);国家科技重大专项项目(编号:2011ZX05005-005);863计划项目(编号:2013AA064201)

摘　　要：波动方程逆时偏移是目前比较精确的基于波动理论的深度域偏移成像方法,但逆时偏移成像条件的运用会产生低频噪音,影响成像质量及层位的准确性。依据低频噪声的产生机理,运用交错网格有限差分法求取各向同性介质中的地震波场,通过对比炮点与检波点波场在不同频率条件下的互相关成像特征,分析其子波频率与周期差异(或时移)条件下逆时偏移成像对层位解释精度与低频噪音产生的影响,提出了改进的时移逆时偏移成像层位校正方法和低频噪声压制策略。数据算例表明,改进后的时移逆时偏移成像有效的压制了低频噪声,成像层位准确。The wave equation reverse-time migration is a rather accurate depth domain migration imaging method based on wave theory. But the application of reverse-time migration imaging conditions will produce low frequency noise, thus impacting imaging quality and horizon interpretation accuracy. Considering low frequency noise forming mechanism, using staggered grid finite difference method to evaluate seismic wave field in isotropic media, through comparison of shotpoint and geophone station wave fields＇ mutual correlation imaging features under different frequency conditions analyzed impacts on horizon interpretation accuracy and low frequency noise from reverse-time migration imaging under wavelet frequency and periodic differences（or time shifting）, put forward an improved time shifting reverse-time migration imaging horizon correction method and low frequency suppression tactics. The numerical examples have shown that the improved time shifting reverse-time migration imaging can effectively suppress low frequency noise and get correct imaging horizons.

关 键 词：各向同性介质 逆时偏移 成像层位校正 低频噪声 

分 类 号：P631.4[天文地球—地质矿产勘探]