表层季节性冻土对地震资料品质的影响  

The influence of seismic data quality by seasonal permafrost

作　　者：陈敬国 袁胜辉 唐传章 崔宏良 李景叶[1] 邓志文 CHEN Jingguo;YUAN Shenghui;TANG Chuanzhang;CUI Hongliang;LI Jingye;DENG Zhiwen(College of Geophysics,China University of Petroleum(Beijing),Beijing 102249,China;BGP Inc.,CNPC,Zhuozhou,Hebei 072751,China;Huabei Oilfield Company,PetroChina,Renqiu,Hebei 062550,China)

机构地区：[1]中国石油大学(北京)地球物理学院,北京102249 [2]中国石油集团东方地球物理公司,河北涿州072751 [3]中国石油华北油田公司,河北任丘062550

出　　处：《石油地球物理勘探》2023年第6期1343-1348,共6页Oil Geophysical Prospecting

基　　金：中国石油股份公司重大科技专项“河套盆地油气富集规律与勘探关键技术研究”(2021DJ0703);中国石油集团东方地球物理公司科研项目“地震采集方法基础研究”(03-01-2022)联合资助。

摘　　要：大部分农田、草原区由于地表植被的保护,地震勘探只能选择在农作物收割后的冬季施工。中国北方地区基本在每年10月中旬浇灌农田,导致土壤含水性高,冬季会形成一套高速冻土层,增加了近地表结构的复杂性。可控震源在地表激发信号,地震波在冻土层中传播会受到冻土介质共振频率的影响,减弱了地震波低频信号的能量。为此,提出利用冻土的耦合共振频率,开展冻土层的地震波传播机理研究。结果表明,冻土层覆盖后,接收的低频信息减弱,频谱整体向高频端移动。实际资料处理表明,冻土层耦合共振频率可拓展高频、补偿低频,适用性强。该方法为季节性冻土地区可控震源采集资料品质的改善提供了一种解决思路。Due to the protection of surface vegetation in most farmland and grassland areas,seismic exploration can only be carried out in winter after the harvest of crops.People in northern China typically irrigate their farmland around mid-October each year,resulting in high water content in the soil and low winter temperatures.As the soil freezes on the surface,a set of high-speed permafrost layers form,adding complexity to near-surface structures.Vibroseis excite signals at the surface,and seismic wave propagation in frozen soil will be affected by the resonance frequency of frozen soil medium,weakening the energy of low-frequency seismic wave signals.The Results indicate that after the permafrost layer is covered,the received low-frequency information weakers and the overall spectrum shifts towards high-frequency section.In view of the complex near-surface structure caused by seasonal frozen soil,the seismic wave propagation mechanism of frozen soil layer and the actual data analysis are carried out in this paper,which can provide a solution for improving the quality of vibroseis acquisition data in seasonal frozen soil area.

关 键 词：冻土层 近地表 模型正演 资料品质 阻尼力 吸收衰减 共振频率 

分 类 号：P631[天文地球—地质矿产勘探]