论文部分内容阅读
γ能谱法鉴别钻井岩屑沉积岩类别,有助于解决沉积岩小类划分困难以及化学分析时间长等问题。介绍了通过低本底γ能谱法测定钻井岩屑中的天然放射性核素K、U、Th含量来划分泥岩中的深灰色含灰泥岩、深灰色灰质泥岩以及灰色灰质泥岩的方法。分别选用1.37–1.56 Me V、1.66–1.86 Me V以及2.41–2.81 Me V能区的计数率来代表K、U、Th的放射性强度。利用SPSS(Statistical Product and Service Solutions)软件对这三种泥岩的K、U、Th计数率以及总计数率对岩石岩性进行费歇尔判别分析,其岩性识别正确率分别为100%、76.47%和60%。由实验可得,根据K、U、Th及总的计数率基本可识别深灰色含灰泥岩,而对于深灰色灰质泥岩以及灰色灰质泥岩的识别效果较好,但不能完全区分。
γ spectroscopy to identify the types of sedimentary rocks in the drilling cuttings helps to solve the problems of subdivision of sedimentary rocks and the long chemical analysis time. The method for determining the dark gray gray-gray mudstone, dark gray gray mudstone and gray gray mudstone in mudstone by using low background gamma spectrometry to determine the content of natural radionuclides K, U, Th in drilling cuttings. The counting rates of 1.37-1.56 Me V, 1.66-1.86 Me V and 2.41-2.81 Me V are chosen to represent the radioactivity intensity of K, U, Th respectively. Fresnel discriminant analysis of rock lithology using K, U, Th count rate and total count rate of the three kinds of mudstone using the software of SPSS (Statistical Product and Service Solutions) shows that lithology identification accuracy is 100%, 76.47 % And 60%. According to K, U, Th and the total count rate, the dark gray stucco rock can be identified basically, while the dark gray limestone mudstone and gray limestone mudstone have good recognition effect, but they can not be completely distinguished.