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

摘要： 应用激光共聚焦显微镜等新技术对松辽盆地北部兴城地区砾岩储层微观特征的系统研究表明,砾岩发育砾内(压裂成因)裂缝和砾间裂缝。对砾岩微裂缝和不同类型孔隙数量的定量评价及孔隙成因分析表明,砾岩普遍发育微裂缝是其排驱压力和物性下限虽然低于砂岩但仍能成为有利储层的主要原因之一。砾岩含砂量、粒度、砾石成分、填隙物类型及含量、储层物性特征等分析表明,沉积相(含砂量)是储层物性的主要影响因素,并明确了沉积相-岩性特征-物性特征关系。应用砾岩单层物性与试气结果,确定了砾岩储层下限孔隙度为2.7%,下限渗透率为0.05×10^-3μm²,并进一步研究了储层物性与产能的关系。

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