基于敏感元素特征谱图的岩性识别方法

Lithology identification method based on characteristic map of sensitive elements

应用元素录井技术测定地层元素含量变化,可以辅助判别地层岩性和层位,对于元素含量差异大的层段识别效果较好,但在岩性复杂、元素含量特征相近的地层中,应用效果难以保证。利用渤海探区已取得的元素录井资料,建立不同地层单元的岩性与元素对比数据库,并采用交会分析法提取敏感元素,形成不同地层单元不同岩性的敏感元素标准谱图,在此基础上,利用线性回归方法将实测岩样敏感元素分别与不同岩性标准谱图的敏感元素进行相关性分析,通过定量化的方法匹配相似度,实现岩性比对判别。通过在渤海探区的实践应用表明,该方法能够实现地层岩性的定量化判别,有效消除岩性识别过程中由于人为因素产生的偏差,对于复杂岩性的准确识别具有较强的实用性。

Determining the change of element content of formation by element logging technology can assist in the identification of lithology and layer of the formation,with better effect for intervals with large difference in element content but unsure effect for formations with complex lithology and similar element content characteristics.Using the element logging data obtained in Bohai Sea exploration area to establish the lithology and element comparison database of different stratigraphic units,and the sensitive elements are extracted by the intersection analysis method to form standard spectra of sensitive elements with different lithologies in different stratigraphic units.The linear regression is used to analyze the correlation between sensitive elements of measured rock samples and sensitive elements of different lithology standard spectra.The similarity is matched by a quantitative method to realize the comparison and discrimination of lithology.The application in Bohai Sea exploration area indicates that the method can realize quatitative identification of formation lithology,and effectively eliminate the deviation caused by human factors in lithology identification,providing strong practicality for the accurate identification of complex lithology.