松辽盆地营城组火山岩成岩作用类型、特征及其对储层物性的影响

通过野外剖面观察、钻井岩心描述、薄片鉴定和扫描电镜分析，松辽盆地营城组火山岩的成岩作用阶段分为早期和晚期。早期成岩作用类型有挥发分逸出、熔蚀作用、等容冷凝结晶、准同生期热液沉淀结晶、熔结作用、冷凝收缩、分熔冷凝结晶和早期压实胶结作用；晚期成岩作用类型为充填作用、脱玻化作用、交代作用、机械压实压溶作用、胶结作用和溶解作用。早期成岩作用主要影响原生孔隙的发育，晚期成岩作用影响次生孔隙的发育。准同生期热液沉淀结晶、早期压实胶结作用、充填作用、机械压实压溶作用和胶结作用是使松辽盆地营城组火山岩储层物性降低的主要成岩作用；挥发分逸出、等容冷凝结晶、冷凝收缩和溶解作用是产生孔隙空间使储层物性变好的主要成岩作用。

Diagenesis Types and Features of Volcanic rocks and Its Impact on Porosity and Permeability in Yingcheng Formation, Songliao Basin

The diagenesis of volcanic rocks in Yingcheng Formation was classified as the early diagenesis and late diagenesis based on the observation of outcrop,well core,thin section and the analysis with scanning electric microscope.The early diagenesis includes corrosion,vaporization of volatile matter,isovolumetric condensing crystallization,pene-contemporaneous hydrothermal precipitation and crystallization,fusion,condensing constriction,differentiation condensing crystallization and the early impaction-cementation.The late diagenesis includes filling,devitrification,metasomatism,mechanical impaction and pressure solution,cementation and dissolution.The early diagenesis mainly influences the development of primary pore and the late diagenesis mainly influences the development of secondary pores.The pene-contemporaneous hydrothermal precipitation and crystallization,the early impaction-cementation,the filling,the mechanical impaction and pressure solution and cementation will harm the porosity and permeability of volcanic reservoir.The porosity and permeability will be improved after the vaporization of volatile matter,the isovolumetric condensing crystallization,the condensing constriction and dissolution.