火山岩岩石微观特征及其测井宏观表征

基于图像处理技术，分析华北某油田深层火山岩薄片图像灰度频率分布规律，研究储层岩石孔隙结构微观特 征，并探索其与火山岩储层测井的响应关系。研究表明：本区酸性火山岩薄片灰度频率分布图主要呈单峰特征，具有 高硅、低铁特征；基性火山岩为明显非对称分布，具有低硅、高铁特征。火山岩薄片图像中硅质成分的灰度域与GR 范 围对应性较好。基性火山岩GR 值低，硅质成分灰度域值小；酸性火山岩GR 值高，硅质成分灰度域值大。GR 值可以 作为硅质成分的指示值，用于基性火山岩和酸性火山岩识别。基性火山岩受蚀变影响较普遍，绿泥石化越严重，电阻 率越低，中子孔隙度越大，硅质成分向灰度小的方向偏移越剧烈。

Microscopic Characteristics and Logging Macro Characterization of#br# Volcanic Rocks

Based on the image processing techniques，this paper analyzes the gray frequency distribution of image of the thin sections in deep volcanic rocks from a certain oil field in north China，and investigates the microscopic characteristics of the pore structures of reservoirs and their relationships with the log response of volcanic reservoirs. The research shows that the thin sections in acid-volcanic-rock in this area are characterized by high silicon and low iron and that the line graph of their gray frequency presents unimodal characteristics. However，the basic volcanic rock obviously presents asymmetric distribution and shows a low silicon and high iron characteristics. Gray threshold value of the siliceous component corresponds to the range of GR better in the image of thin sections of volcanic rocks. The GR value of basic volcanic rocks is low and gray value of the siliceous component is small. The GR value and gray threshold value of the siliceous component of acid-volcanic-rock are high. So the GR value can be used as the siliceous component to identify the basic volcanic rocks and acid volcanic rocks. For basic volcanic rocks，the more serious the chloritization，the lower the resistivity，the higher the neutron porosity，the more intense the siliceous component move towards the direction of the smaller gray value.