塔里木盆地英买35井区志留系储层石英增生机理及意义

Mechanism and its significance of quartz overgrowth in Silurian reservoir,Yingmai 35 Well area,Tarim Basin

在英买35井区志留系柯坪塔格组上段,针对致密海相石英砂岩储层的成因,结合薄片、包裹体测温、伊利石测年、阴极发光等资料,认为石英砂岩存在4期主要的石英增生:1泥盆纪、石炭纪,来源于寒武系硅质生物遗骸中的硅质增生;2二叠纪火山喷发,来源于寒武系、奥陶系、志留系的硅质大量增生;3三叠纪、侏罗纪地层暴露剥蚀,来源于二叠系凝灰岩的硅质增生;4白垩纪至今地层快速沉降深埋,志留系成岩活动加剧,硅质析出增生。二叠系火成岩喷发提供了石英增生的动力与物源。毗邻二叠系火成岩侵入体的志留系砂岩储层存在热接触变质带和致密胶结带。

Aiming at tight reservoir in marine quartz sandstone,combined with thin section,inclusion temperature,illite dating,cathodoluminescence,four stage quartz overgrowths were recognized in quartz sandstone,upper member of Kepingtage Formation,Silurian of Yingmai 35 Well area.（1）Quartz overgrowth whose silicon came from Cambrian siliceous biological remains in Devonian-Carboniferous;（2）Massive quartz overgrowth whose silicon came from Cambrian-Ordovician-Silurian formation during Permian volcanic eruption;（3）Quartz overgrowth whose silicon came from Permian volcanic tuff exposed and denuded during Triassic-Jurassic;（4）Quartz overgrowth because of Silurian Formation active diagenesis due to formation＇s fast sinking and deep burying,which happened from Cretaceous to present.Eruption of Permian igneous provided dynamic power and provenance for quartz overgrowth.Silurian sandstone formation included thermal contact aureole and dense cement zone,which was adjacent to Permian intrusive igneous rock.