自然伽玛及自然伽玛能谱测井在沉积盆地古环境反演中的应用

对山东东营凹陷牛38井古近系沙河街组三段的自然伽玛和自然伽玛能谱测井的初步实验研究表明，在比较稳定的还原性古环境中，能谱测井中的铀（U）含量和钍、铀含量比(Th/U)，能作为古环境研究的重要指示参数，而伽玛总量则不然．U及Th/U与有机碳含量（co）存在良好相关性，在比较安静、还原性的古环境中（有机碳含量大于4．0%时），两参数具有较强的应用性，而随着古环境的开放性及动荡性增强，其应用能力减弱．

APPLICATION OF NATURAL GAMMA RAY LOGGING AND NATURAL GAMMA SPECTROMETRY LOGGING TO RECOVERING PALEOENVIRONMENT OF SEDIMENTARY BASIN

The application of the natural gamma ray (GR) curve and the natural gamma spectrometry (NGS) curve to the Member 3 of the Shahejie Formation from the well Niu-38 in the Dongying depression indicates that the GR curve can not reflect the change of the paleoenvironment well,but the curves of uranium (U) and the ratio of thorium to uranium (Th/U) from NGS are consistent with the change of paleoenvironment and have good correlation with the contents of carbon organic,which suggests that U and Th/U are better parameters for paleoenvironment than GR.In the quiet and deoxidize condition U and Th/U are much applicable,with the conditions having more oxidation their capability of application is weaken.So the application of the GR curve in the recovering of paleoenvironment should be together with the NGS curve,and the NGS curve should be used as a criterion.