准噶尔盆地哈山地区石炭系火山岩储层特征及控制因素

Characteristics and controlling factors of carboniferous volcanic reservoir in Hashan area of Junggar basin

准噶尔盆地哈山地区紧邻玛湖富生烃凹陷,是油气运移和聚集的有利指向区.为认识哈山地区石炭系火山岩储层特征及主控因素,利用岩心、薄片及成像测井手段,分析火山岩岩石学特征、储集空间类型、储层物性特征等,研究哈山地区石炭系火山岩储层特征及储集性能主控因素.结果表明:研究区内火山岩岩石类型复杂,主要为火山角砾岩、安山岩、凝灰岩和玄武岩;储集空间类型主要为次生溶孔、裂缝及少量原生孔隙(砾间孔和残余气孔);储集性能较差,以中低孔—低渗(特低渗)储层为主,非均质性强,火山角砾岩物性最好,是石炭系最有利的储集层,其次是安山岩和凝灰岩,玄武岩储集性能最差;储集性能影响因素主要有火山岩的岩性、岩相、构造活动及溶蚀作用.该研究结果对准噶尔盆地哈山地区油气勘探开发具有指导意义.

Hashan area of Junggar Basin is adjacent to the Mahu hydrocarbon generation depression.It was a favorable guiding zone for oil and gas migration and accumulation.Based on volcanic petrologic characteristics,reservoir space type,reservoir physical property and etc.,volcanic reservoir characteristics of Carboniferous in Hashan area of Junggar basin are studied by using the methods of core observation,thin section identification(conventional and casting thin section)and image log etc.The reservoir accumulation type and the main affecting factors of reservoir physical property were also analyzed.The results show that there existed complex types of volcanic rocks,mainly including volcanic breccia,andesite,tuff and basalt in the operation area.The volcanic reservoir space includes secondary dissolution pores,cracks and a small number of primary porosity(inter-gravel holes and residual porosity)in the operation area.The reservoir was mainly characterized by low-middle porosity and low permeability(or ultra-low permeability)with strong heterogeneity.Physical property of the volcanic breccia and andesite are relatively better,followed by tuff,and physical property of the basalt is poorest.Lithology,lithic facies,tectonism and dissolution are the main influencing factors of reservoir physical property.