江陵凹陷荆州背斜带沙市组下段含盐岩系测井岩性识别

Well Logging Lithology Identification of the Salt-Bearing Rock Series in the Lower Member of Shashi Formation, Jingzhou Anticline Belt, Jiangling Depression

摘要: 多年来，国内外学者不断致力于盐岩矿床的评价与研究。对于盐岩矿床的岩性识别研究是盐矿勘查和开发中的关键环节之一。通过对钻孔中地球物理测井数据的分析和综合处理，可以进一步了解地下岩石的性质、组成和分布，为盐矿勘查和开发提供重要的技术支持。针对江陵凹陷沙市组下段含盐岩系四口钻孔的取心岩心编录和测井资料，采用交会图法对研究区的地层开展了岩性识别研究。结果表明，研究区内有盐岩、钙芒硝岩和泥岩3种类型，利用DEN-GR、RLLD-GR两两交汇，能够有效的划分地层岩性。利用交会图法构建的岩性识别模型，对于沙市组下段含盐岩系的岩性识别准确率高达92.5%。所建立的测井岩性识别模型能够准确识别研究区地层岩性，对含盐岩系后期勘查开发测井识别与评价具有重要的参考价值。

Abstract: Over the years, domestic and international scholars have continuously dedicated efforts to the evaluation and research of salt rock deposits. Lithology identification of salt rock deposits constitutes one of the critical links in salt deposit exploration and development. Through the analysis and comprehensive processing of geophysical well logging data from boreholes, a deeper understanding of the properties, composition, and distribution of subsurface rocks can be achieved, thereby providing essential technical support for salt deposit exploration and development. Based on the core logging records and well logging data from four boreholes in the salt-bearing rock series of the Lower Member of Shashi Formation within Jiangling Depression, this study conducted lithology identification of the strata using the cross-plotting method. The results indicate that three lithofacies are present in the study area: salt rock, glauberite rock, and mudstone. By applying pairwise cross-plots of DEN-GR and RLLD-GR, the lithology of strata can be effectively discriminated. The lithology identification model constructed via the cross-plotting method achieves an accuracy rate of up to 92.5% for lithology identification of the salt-bearing rock series in the Lower Member of Shashi Formation. The established well logging lithology identification model can accurately identify the lithology of strata in the study area, holding significant reference value for the later-stage exploration, development, well logging identification, and evaluation of salt-bearing rock series.