叠前弹性波阻抗反演在流体检测中的应用——以渤海海域QHD29-2区块为例

Application of pre-stack elastic wave impedance inversion technique in the fluid detection of QHD 29-2 area in Bohai Sea

常规叠后波阻抗反演和叠前弹性波阻抗反演技术难以有效预测和描述QHD29-2区块储层和流体的展布范围,为此,采用了基于Russell近似的叠前弹性波阻抗反演技术。该反演技术直接从流体弹性波阻抗反演数据体中提取对流体类型较敏感的流体因子f和剪切模量μ,使弹性阻抗与流体因子相关联,最终反演结果兼顾常规弹性阻抗反演的高抗噪性以及利用流体因子进行流体识别的直观性,有效地减少了常规流体因子间接计算的误差累积。利用叠前弹性阻抗反演方法进行QHD29-2区块东营组三段流体检测,进一步提高了该区块含油气储层物性横向变化的认识。

Traditional post-stack wave impedance inversion and pre-stack elastic wave impedance inversion techniques cannot effectively predict and describe the distribution of reservoirs and fluid in QHD29- 2 area.Therefore,we adopted pre-stack elastic impedance inversion technique based on Russell approximation.By using this method, the fluid factor f and shear modulusμwhich is sensitive to fluid type can be directly extracted from elastic wave impedance inversion data volume,which connects the elastic impedance and fluid factor.The inversion result obtained by the above method compromises high anti-noise performance of conventional elastic impedance inversion and the intuition by utilizing fluid factor for fluid identification, which effectively reduces the error cumulative process caused by the indirect computation of conventional method.The pre-stack elastic impedance inversion method based on Russell approximation was utilized to detect the fluid in QHD29-2 Block,and we achieved deeper recognition on the lateral variation of physical properties of the reservoirs.