火山岩储层储集空间的构成——以松辽盆地为例

火山岩气藏勘探的核心问题是储层预测，而储层预测的关键是看储集空间是否发育。为此，采集了松辽盆地下白垩统营城组野外露头区及钻井区167块代表性样品，通过对岩石薄片和铸体薄片的观察，利用面孔率统计方法和物性数据分析，研究了火山岩储集空间的构成问题，对比了不同岩性岩相的原生孔隙、次生孔隙和裂缝发育情况，并探讨了原生孔隙和次生孔隙的成因。结论认为：①气孔火山熔岩原生孔隙最发育；致密火山熔岩和火山碎屑熔岩的原生孔隙、次生孔隙、裂缝发育比例相近，前者裂缝较发育，后者原生孔隙较发育；火山碎屑岩和沉火山碎屑岩次生孔隙和裂缝发育比例较大。②火山通道相以砾间孔和裂缝为主；爆发相和喷溢相从底部→顶部各亚相，原生孔隙发育比例上升，次生孔隙和构造缝发育比例下降；侵出相以原生收缩缝为主，火山沉积相以次生孔缝为主。③发育气孔构造、石泡构造、气孔杏仁构造、流纹构造、珍珠构造、柱状节理、间粒结构和熔蚀结构的火山岩易形成原生孔缝；构造作用、风化淋滤作用、溶蚀作用和脱玻化作用等后期成岩作用促进了次生孔隙和裂缝的形成。以上认识对火山岩储层内部构成的细化及火山岩气藏的开发有借鉴意义。

Components of volcanic reservoir space:A case study from the Songliao Basin

Reservoir prediction is the core of volcanic gas reservoir exploration and its focus is the prediction of reservoir space development.A total of 167 outcrop and core samples were collected from the Upper Jurassic Yingcheng Formation in the Songliao Basin.Based on the observation of ordinary and cast thin sections and statistics of surface pores and analyses of poroperm characteristics,the components of volcanic reservoir space,the comparison of the primary pores,secondary pores and fissures in samples of di...