柴西北小梁山地区混积岩测井岩性识别

Lithology Identification on Mixing Deposit with Logging Data in Northwest Xiaoliangshan of Qaidam Basin

柴达木盆地西北部的小梁山背斜构造,陆源碎屑和湖相碳酸盐混合沉积广泛发育,地层岩石类型多样,测井响应特征复杂,岩性识别非常困难。结合岩石物理实验数据(铸体薄片、粒度分析、X射线衍射全岩分析、碳氯分析)和测井资料,对研究区混积岩岩石组分的类型、粒度和质量分数进行了细致的分析研究,以岩石组分的相对质量分数和测井响应特征为依据,对岩性进行了简化归类,建立了测井资料识别岩性标准,在此基础上利用ΔGR、Δlg(LLD)和M参数绘制了混积岩岩性识别电性组合图,并建立了岩性质量分数计算模型,形成了一套小梁山地区测井岩性综合识别方法,为小梁山地区的储层测井评价和综合地质研究奠定了基础,对中浅层混积岩的测井解释研究具有借鉴与参考意义。

Diamictites, composed of terrigenous and carbonate clasts of lacustrine facies are extensively developed in the Xiaoliangshan anticline in the northwest Qaidam Basin. The lithological diversity of the deposit causes the com- plexity of logging response and difficulties in rock type identification from the drilling cores. We combine petro- physical parameters （X-ray diffraction, rock slabs, thin-section, carbon chloride analysis, and grain size analysis） and logging material to carry out a detailed analysis on mineral components, content and particle size of the diamic- tite, and classify the rock based on logging response characteristics and mineral components, which provide a standard of lithological identification. On that basis, we propose an identification electrical crossplot for diamictites and build a material content calculation model by using AGR, Alg （LLD） and M parameters. This helps to form a logging lithological identification method for reservoir evaluation and comprehensive geological research in the Xia- oliangshan region, and has application for interpretation of other diamictite deposits worldwide.