泥质砂岩的激发极化弛豫时间谱反演

Induced Polarization Relaxation Time Spectra Inversion of Shaly Sands

激发极化谱较极化率具有更为丰富的储层信息。为更好地利用激发极化谱评价储层，采用正则化方法并结合奇异值分解技术对泥质砂岩的激发极化衰减谱进行了多指数反演，得到了连续光滑的弛豫时间谱。在激发极化衰减谱信噪比较高的情况下，约束条件矩阵不影响反演结果，而且弛豫时间分布点数为32-64较为合适。可以利用激发极化弛豫时间谱进行地层渗透率评价，logK随log（Eg^4/2／F）线性增加。

The induced polarization decay curve contains more information than the polarizability which was used in the conventional induced polarization logging tool. In order to characterize the res ervoir using induced polarization, a regularization inversion method combined with the singular value decomposition method is used to inverse the induced polarization relaxation spectra of the shaly sands. The resulted spectra are continuous, and independent on the restriction matrixes while the signal-tonoise ratio is higher in the induced polarization decay signal. The appropriate number of relaxation arrangement points in relaxation data inversion ranges from 32 to 64. The result shows that the IP relaxation time spectra can be used to determine the permeability of the cores, log K increases linearly with log（Tg^1/2/F） increasing.