准噶尔盆地西北缘二叠系佳木河组火山岩有效储层特征与定量评价

通过地质、测井及生产动态资料综合分析,对准噶尔盆地西北缘金龙2井区二叠系佳木河组火山岩储层特征进行研究。结果表明:佳木河组火山岩有效储层岩性主要为安山质(熔结)角砾岩、安山质/玄武质角砾熔岩及安山岩等,储集空间类型以气孔、溶蚀孔为主,其次为晶间孔及砾间孔,总体表现为中低孔、低渗特低渗特征;火山岩有效储层微观孔喉特征主要表现为单峰粗态、偏粗态及双峰偏粗态的细孔喉型;应用聚类分析方法与典型Fisher判别方法将火山岩有效储层进一步定量细分为3类;依据火山岩有效储层定量评价方法,优选试验部署区域,现场实际应用效果显著,为火山岩油藏高效开发部署提供了有力的技术支撑。

Characteristics and quantitative evaluation of volcanic effective reservoir in Jiamuhe Formation of Permian, northwestern margin of Junggar Basin

Based on a comprehensive analysis of geological, well-logging and production data, this paper summarized the characteristics of volcanic effective reservoir of Permian Jiamuhe Formation in Jinlong2 area, the northwestern margin of Junggar Basin. The lithology of volcanic effective reservoir mainly includes andesitic (welded) breccia, andesitic/basaltic brecciated lava and andesite. The reservoir spaces are mainly composed of stomata and dissolution pore, followed by intercrystalline pore and intergranular pore. The volcanic reservoir is totally characterized by low-medium porosity and low-extra low permeability. Using capillary pressure curves which represent different types of volcanic rock, it can be shown that the characteristics of the microscopic pore throat in effective reservoirs mainly express in fine pore type with unimodal coarse state, partial coarse state and bimodal partial coarse state. Based on the analysis and evaluation of macroscopic physical characteristics as well as microscopic pore structure, this paper further optimizes K-means clustering analysis method and typical Fisher discriminant method to set up quantitative classification and evaluation criteria and discriminant functions, which divide the volcanic effective reservoir into three types accordingly. This quantitative evaluation classification method was applied to the development test area, and yielded remarkable results. The method may provide strong technical supports for the efficient development of volcanic reservoir.