天然气勘探与开发2025，Vol.48Issue(6)：64-75,12.DOI:10.12055/gaskk.issn.1673-3177.2025.06.006
基于AutoScan测量实验的灯影组岩石表面电阻率特征分析
Characteristic analysis of rock surface resistivity of Dengying Formation based on AutoScan measurement experiment
摘要
Abstract
The carbonate rocks in the Upper Sinian Dengying Formation of the Sichuan Basin are diverse in composition and structure,with rich geological features on the core surface.Electrical imaging logging is the primary technique to detect such features.However,there may exist inconsistencies between core observations and imaging logging interpretations.It is urgently necessary to establish a characteristic chart of electric field distribution for typical rock lithology and pore structure based on cores to guide the interpretation of electrical imaging logging data.In order to clarify the influence of rock surface structure on logging electrical properties,the AutoScan scanner was used to measure the rock surface electrical fields of 24 cores from the Dengying Formation.Through such systematic measurement with precisely designated scanning area and strictly controlled parameters,the electrical features were summarized for different rock compositions and microstructures.The results are obtained in four aspects.(i)Both porosity and lithology variations can cause changes in core surface resistivity values,with the former having a greater impact.(ii)The resistivity contour map closely matches the morphology of core fractures,but due to the limitation of measurement accuracy,the fracture widths obtained by electrical field measurement are 4.0-11.4 times larger than the actual ones in cores.(iii)Microbial development also affects the electrical properties of rock surface.The grape lace structure leads to a local increase in resistivity,while microbial forms such as algal laminations and ooids reduce the resistivity.(iv)The influence of surface electrical field varies with minerals.Chalcopyrites and feldspars lead to a decrease in resistivity(with a maximum reduction of 16.48 times),while quartz minerals increase the resistivity(by 2.38 times approximately).It is concluded that the electrical field characteristics of rock surface are primarily controlled by pore structure,followed by lithology and mineral composition.The established quantitative chart of"geological feature-electrical response"can provide a theoretical evidence and data support for fracture-vug identification,lithology assessment,and ambiguity mitigation in electrical imaging logging.关键词
四川盆地/碳酸盐岩/震旦系上统灯影组/表面电场/电阻率/AutoScan测量/电成像测井/"地质特征—电性响应"量化图版Key words
Sichuan Basin/Carbonate rock/Upper Sinian Dengying Formation/Surface electrical field/Resistivity/AutoScan measurement/Electrical imaging logging/Quantitative chart of"geological feature-electrical response"分类
能源科技引用本文复制引用
谌丽,赖强,唐军,吴煜宇,殷榕,汪泽宇..基于AutoScan测量实验的灯影组岩石表面电阻率特征分析[J].天然气勘探与开发,2025,48(6):64-75,12.基金项目
中国石油天然气股份有限公司重大科技专项"复杂碳酸盐岩地球物理评价关键技术研究"(编号:2023ZZ16YJ04). （编号:2023ZZ16YJ04）
