利用声波时差资料研究欠压实浓度盖层抑制封闭作用形成时期及其研究意义

Determining forming period of restrained seal action of undercompacted concentration caprock by using interval travel time data and its research meaning.

欠压实浓度盖层抑制封闭作用的形成取决于异常含气浓度的形成 ,而异常含气浓度的形成又取决于异常孔隙流体压力的形成。根据这种关系 ,利用声波时差资料可以确定出欠压实浓度盖层抑制封闭作用的起、止时期 ,通过对其形成时期与气源岩大量排气期的匹配关系 ,阐述了欠压实浓度盖层抑制封闭作用在封闭扩散相天然气研究中的意义 ,并以松辽盆地三肇凹陷青山口组泥岩盖层为例 ,验证了该方法的实用性。

Forming of restrained seal action of undercompacted concentration caprock depends on forming of anomalous gas-bearing concentration and the later depends on forming of anomalous pore-fluid pressure.According to the relation,the start-stop period of forming of restrained seal action of undercompacted concentration caprock can be determined by using interval travel time data.The meaning that restrained seal action of undercompacted concentration caprock is in study of gas with seal expansion facies has been elaborated from the matching relation between forming period and period of vast amount of gas blow-off in gas source rock.Taking the shale caprock of Qingshankou Formation in Sanzhao depression of Songliao Basin for example,the paper proved that the method is practical.