松辽盆地北部徐家围子断陷火山岩气藏勘探新技术

New methodology to explore gas-bearing volcanic reservoir in Xujiaweizi Fault Depression of the northern Songliao Basin

松辽盆地北部徐家围子地区深层发育了大量的火山岩体,特别是营城组一段,火山岩相以多期的爆发相和喷溢相空间相互叠置为主。火山岩天然气藏广泛分布。勘探实践表明:天然气藏的分布受火山机构和区域构造的控制。火山岩储层在火山口附近的爆发相和喷溢相、相对的局部构造高部位和断裂附近地区比较发育。火山岩物性好坏受地层埋深影响不是很大。各个气藏都在不同的海拔高度见到了水层,说明各个气藏边界受火山岩岩性控制。综合分析研究结果,气藏类型为岩性-构造气藏。火山岩勘探难度大,其成熟方法在国内外不多见,可借鉴的方法很少。结合松辽盆地北部徐家围子地区深层营城组一段火山岩气藏钻探过程,阐述了火山岩气藏勘探方法,深化和丰富了火山岩气藏勘探理论,为以后的火山岩气藏勘探提供了研究方法参考。

Many gas-bearing volcanic reservoirs were discovered in Xujiaweizi Fault Depression of northern Songliao Basin, especially in Yingcheng I Formation. The lithology of the volcanic rock is mainly dominated by the spatial overriding of multi-eruption facies and effusion facies. Early exploration shows that the widely distributed natural gas reservoirs was greatly controlled by developed paleo-craters and areal structure. Eruption facies and effusion facies around volcanic vent, relative high position of local structure and areas near fracture were thought to be prospective exploration areas, The physical properties of volcanic rock were not controlled by the burial depth. Water layer appearing in every gas bearing reservoir at different sea-level elevation, which means the gas reservoir boundary is controlled by lithology. Comprehensive analysis results indicate that the gas reservoir type belongs to litho-strnctural reservoir, Since the exploration work focusing on volcanic rock is very hard, little could be referred from the rarely reported effective and mature methods both at home and in abroad. Combining with the exploration process to the gas bearing volcanic reservoirs of the Yingcheng ⅠFormation in Xujiaweizi Fault Depression, northern Songliao Basin, the authors proposed a volcanic reservoir exploration method, which enriches the volcanic exploration theory and offers analytical references to the further volcanic reservoir exploration work.