关键词: 激光共聚焦显微镜, 砾岩储层, 微裂缝, 孔隙结构, 有利储层, 影响因素

Abstract: Through application of new technologies such as laser confocal microscope, systematic study on microscopic features of conglomerate reservoir as well as fractures inside (caused by compression) or between gravels in Xingcheng area of northern Songliao Basin has been made. Also micro-fractures of conglomerate and amount of various pore types have been quantitatively estimated. After analyzing the origin of pore, it points out that the micro-fractures generally developed within conglomerate reservoir is one of the main causes for favorable layers forming, whose lower limit of drainage pressure and physical property are both lower than those of sandstone. Through analysis on sand-bearing content, granularity of conglomerate, gravel composition,types and content of filling, and physical property of reservoir, it indicates that the sedimentary facies (content of sand bearing) is the key factor to influence the physical property of reservoir. It also makes clear the relationship of sedimentary facies-lithologic feature-physical property. With the physical property of single conglomerate layer and gas testing data, the lowest porosity and permeability is determined as 2.7% and 0.05×10^-3μm² individually. The relationship between physical property and productivity is further analyzed.

Key words: laser confocal microscope, conglomerate reservoir, micro-fracture, pore structure, favorable reservoir, affecting factor