不同地层环境下单一裂缝微电阻率成像响应特征  

Characterization of Micro-resistivity Imaging Response of a Single Fracture in Different Stratigraphic Environments

作　　者：韩华洋 张冲[1,2] 杜惟一 赵腾腾 张文艺 Han Huayang;Zhang Chong;Du Weiyi;Zhao Tengteng;Zhang Wenyi(MOE Key Laboratory of Exploration Technologies for Oil and Gas Resources,Yangtze University,Wuhan Hubei 430100,China;Geophysics and Oil Resources Institute,Yangtze University,Wuhan Hubei 430100,China)

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100 [2]长江大学地球物理与石油资源学院,湖北武汉430100

出　　处：《工程地球物理学报》2023年第6期835-842,共8页Chinese Journal of Engineering Geophysics

基　　金：国家自然科学基金项目(编号:41404084);国家科技重大专项子课题(编号:2017ZX05032-003-005)。

摘　　要：本次研究基于数值模拟软件COMSOL Multiphysics和三维有限元法研究不同地层环境下的裂缝型储层响应特征。根据ERMI(Enhanced Resistivity Micro Imager)电成像仪器构造原理,设计了一套单一裂缝在不同的地层环境下的数值模型,通过改变裂缝的宽度、角度和延长深度得到其视电阻率,并总结响应规律。计算结果显示:在一定条件地层环境(地层对比度>1/1000),识别裂缝宽度的下限为10μm,超过其宽度下限在微电阻率测井响应上不再明显变化;改变裂缝角度,测井响应特征会发生相位变化;改变裂缝延长深度,可以研究探测仪器在裂缝延长深度的阈值,当裂缝径向延伸达到30 mm,响应曲线幅度不再有明显差异。改变地层温度、压力,在裂缝处的微电阻率测井响应显示:地层温度的改变对裂缝的电学响应更剧烈,而地层压力的改变在裂缝处的电学响应不明显。Based on the numerical simulation software COMSOL multiphysics and the three-dimensional finite element method,this paper studys the response characteristics of fractured reservoirs in different geological environments.According to the construction principle of ERMI(enhanced resistivity micro imager)electrical imaging instrument,a numerical model of a single fracture in different geological environments was designed.The apparent resistivity was obtained by changing the width,angle and extended depth of the fracture,and the response law was summarized.The calculation results show that under certain geological conditions(stratigraphic contrast>1/1000),the lower limit for identifying crack width is 10μm.Beyond the lower limit of its width,there is no significant change in the response of micro resistivity logging;Changing the fracture angle results in phase changes in the logging response characteristics;By changing the depth of crack extension,the threshold of the detection instrument at crack extension depth can be studied.When the radial extension of the crack reaches 30 mm,no significant difference is detected in the amplitude of the response curve.By changing the formation temperature and pressure,the micro resistivity logging response at the fracture shows that the change in formation temperature has a more intense electrical response to the fracture,while the change in formation pressure has a less significant electrical response at the fracture.

关 键 词：电成像 有限元法 数值模拟 裂缝参数 响应特征 

分 类 号：P631.8[天文地球—地质矿产勘探]