中国古亚洲域沉积盆地火山岩油气藏储层特征比较及其差异分析

在中国古亚洲域沉积盆地火山岩储层母岩年代和岩性、储集空间类型以及火山岩岩相综合分析的基础上,探讨了火山岩油气藏的储层特征及其差异性。研究表明,中国古亚洲域火山岩储层的母岩发育年代西早东晚,西部的准噶尔、三塘湖和吐哈盆地发育晚古生代海相、海陆交互相的中基性安山岩、玄武岩及火山碎屑岩;东部的松辽、二连和海拉尔盆地发育中生代陆相中酸性流纹岩、安山岩。火山岩原生储集空间包括气孔、孔洞以及冷凝收缩裂缝等;次生储集空间包括各种溶蚀孔及构造裂缝、风化裂缝等。火山岩岩相可分喷出相、火山通道相、次火山相和火山沉积相。其中中基性岩类多以溢流相开始,相序类型为溢流相、爆发相/火山沉积相;中酸性岩类多以爆发相或火山通道相发端,主要相序为爆发相、溢流相/侵出相。溢流相一般发育原生气孔、构造缝;爆发相多为粒间孔,而侵出相以角砾间孔和原生裂缝为主。火山岩储层的差异受多因素影响,包括岩性岩相、喷发环境以及后期构造、成岩作用等。前者奠定火山岩储层形成与分布的基础和储集空间的发育程度;后者则改造储层的储渗性能。

Reservoir Characteristic Comparison and Difference Analysis of Volcanic Reservoirs in the Paleo-Asian Domain's Basin, China

According to analysis the ages and lithology of parent rocks in volcanic reservoirs, the types of reservoir space and lithofacies of volcanic rocks, which distribute in the basins all around the paleo-Asian tectonic domain of China, the article discusses the reservoir characteristics and difference of volcanic oil and gas pool. In the paleo-Asian tectonic domain of China, the research indicates that the parent rocks in volcanic reservoir develop in a regular pattern: western parent rocks age is older than eastern. The Junggar basin, Santanghu basin and Tuha basin which located in the west develop marine and marine-terrigenous medium-basic andesite, basalt and pyroclastic rocks of the late Palaeozoic; and the Songliao basin, Erlian basin and Hailaer basin located in the east develop continental intermediate-acid rhyolite and andesite of the Mesozoic. The primary reservoir space of volcanic rock includes pores, cavity and solidification contraction fractures; the secondary reservoir space includes various of dissolved pores, structural fractures and weathered fractures. The volcanic lithofacies can be divided into extrusive facies, conduit facies, subvolcanic facies and volcanic sedimentary facies. Most of intermediate-basic rocks begin with effusive facies, and the type of phase sequence is effusive facies, explosive facies/volcanic sedimentary facies; Most of the intermediate-acid rocks begin with explosive facies or conduit facies, the main phase sequence is explosive facies, effusive facies/ extrusive facies. The effusive facies develop primary pores and structural fracture; Explosive facies develop intergranular pore; Inter-breccia pore and primary fracture are dominant in the extrusive facies. Several factors effect the difference of volcanic reservoir, such as lithology and lithofacies, eruption environment, late reformation and diagenesis. The first two factors control the formation and distribution of volcanic reservoir and development of reservoir space; the rest reform storage property and permeability of the reservoir.