基于指数追踪算法的灰岩底强反射剥离技术--在惠州地区的应用  

Limestone bottom strong reflection separating technology based on exponential matching pursuit algorithm-a case in Huizhou area

作　　者：刘汉卿 陈维涛 孙辉 罗明 何叶 LIU Hanqing;CHEN Weitao;SUN Hui;LUO Ming;HE Ye(CNOOC China Limited Shenzhen Branch,Shenzhen 518000,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司,深圳518000

出　　处：《物探化探计算技术》2022年第4期435-441,共7页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：中海石油(中国)有限公司综合科研(CNOOC-KJ 135 ZDXM 37 SZ 02 SZ)。

摘　　要：灰岩具有高速、高密的特点,与围岩存在较大波阻抗差异,产生的强反射同相轴淹没了有效储层信息,不利于灰岩下储层预测工作的进行。这里以珠江口盆地惠州地区灰岩下伏L系列储层为例,提出基于层位约束的指数追踪强反射分离方法,通过引入指数拟合因子,提高了算法的运行效率。结合惠州地区地质及钻井情况,利用正演模拟分析了灰岩底强反射对其下伏弱反射信息的响应特征,将珠江组灰岩强反射剥离后,凸显的下伏L系列薄砂体与实钻结果相吻合。表明将强反射界面带来的“伪地震信息”从原始地震剖面中剥离,可更好凸显下伏砂体的有效信息,提高了预测精度,对惠州地区灰岩下L系列薄砂体的预测具有重要应用价值。Limestone has the characteristics of high speed and high density,and has a large impedance difference with the surrounding rock.Therefore,the strong event from limestone submerges the effective reservoir information,which is not conducive to the reservoir prediction under the limestone.This paper takes the L series reservoir underlying limestone in Huizhou area of the Pearl river mouth basin as an example,and proposes the strong reflection separation method based on exponential matching pursuit constrained by horizons.By introducing an exponential fitting factor,this method improves the operating efficiency.Besides,combining the geology and drilling conditions in Huizhou area,we analyze the response characteristics of the strong reflection from limestone bottom to its underlying weak reflection information using forward simulation.Separating the strong reflection of the limestone bottom in Zhujiang Formation,the thin sands of the prominent underlying L series are consistent with the actual drilling results.The test proves that,if we separate the pseudo-seismic information brought by the strong reflection from the original seismic profile,the effective information of the underlying sand body can be better highlighted and the prediction accuracy can be better improved.The method has an important application value for the thin sand bodies of the prediction of L series under limestone in Huizhou area.

关 键 词：指数追踪 灰岩 强反射剥离 砂体识别 惠州地区 

分 类 号：P631.4[天文地球—地质矿产勘探]