陆上地震低频线性干扰形成机制及采集压制方法

低频线性干扰是在地震采集中普遍存在的一类干扰波,对单炮质量有很大影响。因此压制线性干扰,提高资料质量是十分必要的。本文以春光油田以及泌阳古河道区为实验区,讨论了低频线性干扰的形成机制,研究发现线性干扰的强弱与低降速层厚度存在关系。激发点所在低降速层厚度越大,低频线性干扰越强,也即在野外采集时炮点深度越大,线性干扰越弱。试验结果表明,在野外采集过程中加大炮点深度,使得炮点位于高速层界面以下时,线性干扰的压制效果比较好。

The Forming Mechanism and Suppressing Methods of Low Frequency Linear Interference Wave on Land

Low frequency linear interference wave generally exists in collecting seismic data,which has a great influence on the quality of single shot gather.Therefore,it is very necessary to suppress linear interference wave for improving the quality of collecting seismic data.In this paper,taking Pai 10well field in Chunguang oilfield and Biyang ancient stream channel as experimental areas,it discussed the forming mechanism of low frequency linear interference wave.The study found that there exists linear relationship between the thickness of low-velocity layer and the strength of the linear interference wave.When the low-velocity layer is thicker,the low frequency linear interference wave is stronger.So in the field acquisition,with the depth of shot hole growing,the linear interference wave becomes weaker.When the shot point locates in the high-velocity layer,the effect of linear interference wave suppressing is good.