纵波构造控制的共检波点叠加道相关算法研究与应用

P-SV wave common receiver point stack algorithm with P-wave structure control

常规纵波构造控制的共检波点叠加道相关算法在处理复杂地区低信噪比、地下构造起伏较大的转换波地震资料时,容易出现"纵横波叠加剖面构造层位不匹配,导致转换波的构造校正量计算不准确"和"算法收敛于局部极值,叠加剖面出现零空间漂移"的现象。本文针对常规算法的此缺点,分析了该算法的理论原理,提出增强纵横波叠加剖面匹配质量和压制"零空间"现象的改进措施:使用纵波共检波点叠加剖面的构造层位来匹配控制转换波共检波点叠加剖面的构造层位,达到增强纵波CMP叠加剖面和转换波ACCP叠加剖面的层位匹配一致性的目的,提高计算地下构造校正量精度,进而估算较准确的纵横波速度比值;计算共检波点叠加道与拉平后的转换波构造层位之间的绝对静校正量,以克服静校正处理的"零空间"漂移现象。实际转换波资料的应用表明,改进方法能够进一步提高常规纵波构造控制的CRP叠加道相关算法的剩余静校正处理适应能力。

In converted waves common receiver point (CRP) stack processing, conventional stack algorithms of P-wave structure control lead a few problems such as “unmatched structural horizons on P- and S-waves stacked sections”, “inaccurate calculation of structural corrections of P-SV wave data”, “converged local extremum”, and “zero space” drift, especially in complex areas with low signal-to-noise ratio data. We analyzed in this paper the theoretical principle of these conventional algorithms and propose solutions to improving matched quality of P- and S-wave stack, and suppressing the “zero space”. First structural horizons on P-wave CRP stack sections are used to match and control structural horizons on P-SV wave CRP stack sections. So structural horizons between P-wave CMP stack sections and P-SV wave ACCP stack sections are matched, and accurate structural corrections and vP/vScan be calculated. Absolute static corrections between CRP stack traces and flatted horizons of P-SV wave are estimated to overcome “zero space” drift. Applications to P-SV wave data indicate that this proposed approach can enhance residual static corrections of conventional CRP stack algorithms with P-wave structure control. © 2016, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.