混积岩复杂岩性识别方法

Identification of the Complex Lithology of Mixed Rock

陈恭洋 王鹏宇 高阳 张方 印森林

CHENGongyang WANGPengyu GAOYang ZHANGFang YINSenlin

长江大学录井技术与工程研究院, 湖北 荆州 434023 长江大学地球科学学院, 湖北 武汉 430100 中国石油新疆油田公司勘探开发研究院, 新疆 克拉玛依 834000

Institute of Mud Logging Technology and Engineering, Yangtze University, Jingzhou, Hubei 434023, China College of Geoscience, Yangtze University, Wuhan, Hubei 430100, China Research Institute for Exploration and Development, Xinjiang Oilfield Company, CNPC, Karamay, Xinjiang 834000, China

吉木萨尔凹陷二叠系芦草沟组为一套陆源碎屑与碳酸盐矿物混积岩层，矿物类型复杂多样，目前对于芦草沟组岩性的命名方案还存在争议，大大影响了钻井现场对岩性识别的效率。利用X射线荧光光谱分析方法（XRF）、X射线矿物衍射方法（XRD）综合分析岩石的矿物成分及元素含量之间的关系，采用元素交会图版法建立了长石岩屑砂岩、粉细砂岩、泥岩、泥晶白云岩、砂屑云岩及云屑砂岩等6类岩性识别图版，对比发现，符合率可以达80%。这为致密油混积岩现场岩性及甜点识别提供了较好的方法，可以有效指导岩性识别及现场水平井地质导向工作。

The Permian Lucaogou Formation in the Jimsar Sag is a set of terrigenous clastic and carbonate mineral mixed rock layers with complex and diverse mineral types. Currently, controversy still exists surrounding the naming conventions for the lithology of the Lucaogou Formation, which has greatly affected the efficiency of lithology identification at drilling sites. In this paper, X-ray fluorescence (XRF) and X-ray diffraction (XRD) were applied to the comprehensive analysis of the relationship between rock mineral composition and elemental content. By adopting the element cross-plot method, we established six types of lithological identification plots, including feldspar lithic sandstone, fine sandstone, mudstone, mudstone dolomite, sandy dolomite, and dolomitic sandstone. Comparative analysis revealed that the coincidence rate can reach 80%. This provides a good method for in situ lithology and sweet-spot identification of tight oil mixed rock, which could effectively guide lithology identification and geosteering of horizontal wells on site.

10.11885/j.issn.1674-5086.2019.04.08.01