起伏地表无网格井中地震 Q 补偿逆时偏移成像方法  

Q-compensated borehole seismic data reverse time migration with irregular topography based on mesh free method

作　　者：魏国华 谷丙洛[1] 段沛然 张闪闪 李振春 孔庆丰[2] WEI Guohua;GU Bingluo;DUAN Peiran;ZHANG Shanshan;LI Zhenchun;KONG Qingfeng(School of Geosciences in China University of Petroleum(East China),Qingdao 266580,China;Shengli Geophysical Institute in SINOPEC,Dongying 257022,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石油化工股份有限公司胜利油田分公司物探研究院,山东东营257022

出　　处：《中国石油大学学报（自然科学版）》2024年第4期68-79,共12页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(42004093);山东省自然科学基金项目(ZR2020QD050)。

摘　　要：井中地震震源能量弱,地层吸收衰减效应的影响更强;复杂地表及复杂构造对井周精细成像影响巨大,需要发展针对性的井中地震起伏地表衰减补偿偏移成像方法。在径向基函数有限差分方法原理基础上,通过引入混合高斯立方基函数并设计起伏地表节点剖分策略,提出一种高精度的无网格径向基函数起伏地表黏声波数值模拟方法;将该方法应用至改进的基于Kelvin-Voigt模型的黏声波方程,实现高效稳定的井中地震起伏地表无网格Q补偿逆时偏移成像。结果表明,提出的井中地震Q补偿逆时偏移成像方法可以实现高精度的起伏地表井中地震衰减补偿成像,有效恢复剖面能量、校正相位畸变,均衡剖面中的能量分布,提高成像质量。Borehole seismic theoretically offers advantages such as high signal-to-noise ratio,wide frequency band,rich wavefield information,and strong reservoir identification capabilities,allowing for detailed reservoir imaging around the well.However,the source energy of borehole seismic is weak,resulting in stronger absorption attenuation effect in subsurface media compared to surface seismic.Furthermore,irregular topography and complex structure around the borehole significantly impact fine migration imaging.Therefore,it is essential to develop an attenuation compensation migration imaging method suited for irregular topography in borehole seismic.Using the principle of radius-basis-function finite-difference method,we establish a high-precision meshfree radius-basis-function finite-difference method with irregular topography of viscoacoustic wave equation.This method introduces a mixed Gaussian cubic basis-function and designs a node generation strategy for irregular topography.In addition,we apply this method to the improved viscoacoustic wave equation based on Kelvin-Voigt model to implement an efficient and stable Q-compensated reverse time migration.The results demonstrate that the proposed Q-compensated reverse time migration imaging method can achieve high-precision imaging of irregular topography for borehole seismic with attenuation compensation,effectively restoring the profile energy,correcting phase distortion,balancing energy distribution in the profile,and improving imaging quality.

关 键 词：井中地震 起伏地表 径向基函数有限差分 Q补偿逆时偏移 

分 类 号：P631.4[天文地球—地质矿产勘探]