松辽盆地南部红岗油田青山口组砂岩中片钠铝石的形成温度

Formation Temperature of Dawsonite from Qingshankou Formation in the Honggang Oilfield,Southern Songliao Basin

主要以松辽盆地南部红岗油田富含片钠铝石砂岩的红143和红146井为研究对象,通过普通薄片鉴定、茜素红-S染色、扫描电镜、能谱分析、显微测温等分析方法,对研究区含片钠铝石砂岩的成岩共生序列,尤其是流体包裹体均一温度进行了详细的研究。红岗油田成岩共生序列为:黏土矿物→石英次生加大边→方解石→片钠铝石→铁白云石→石英愈合微裂隙。通过流体包裹体测温得出:方解石胶结物的均一温度峰值在110～120℃;石英愈合微裂隙的均一温度峰值在130～140℃。片钠铝石的形成温度介于上述两者之间,在120～130℃。通过与国内外已有的研究成果相比较发现:经过岩浆改造后的砂岩中的片钠铝石的形成温度较低,在25～150℃;以子矿物产于包裹体中的片钠铝石的形成温度相对较高,在250～340℃。红岗油田片钠铝石属于第一种情况,形成温度较低,在120～130℃这个温度区间内。扫描电镜和能谱分析显示,形态上,红岗油田片钠铝石(形成温度在120～130℃)主要为针状,乌尔逊凹陷片钠铝石(形成温度在78.56～115.02℃)的片钠铝石主要为针柱状;化学成分上,红岗油田的片钠铝石与乌尔逊凹陷的片钠铝石相比,前者富Si,贫Na、Al和O,后者富Na、Al和O,贫Si。

This article mainly use the Hong-143 and Hong-146 well that rich in dawsonite-bearing sandstones as reaearch objiects.According to the analysis of conventional thin sections,alizarin red-staining,SEM,INCA energy spectromete,micro-thermometry,the diagenetic paragenesis succession of dawsonite-bearing sandstones,in particular,the homogenization tempreature of fluid inclusion have been studied in detail.The diagenetic paragenesis of the Honggang Oilfield is clay minerals→secondary quartz overgrowths→calcite→dawsonite→ankerite→quartz healing microfracture.On the basis of intensive micro-thermometry,the peak of the homogenization tempreature is 110~120℃ in the calcite;while 130~140℃ in the quartz healing microfracture.The formation temperature of dawsonite is between calcite and quartz healing microfracture,which is 120~130℃.Comparing with research results at home and abroad,the formation temperature of dawsonite that is transformed by magma is relatively low,which is 25~150℃.The formation temperature of dawsonite that appeared in the inclusion as daughter mineral is relatively high,which is 250~340℃.The dawsonite in the southern Songliao Basin belong to the first situation,the formation temperature is relatively low,which is 120~130℃.Scanning electron microscopy and energy spectrum analysis shows that the dawsonite of Hong gang oil filed（The formation of temperature between 120~130℃） is mainly needle-like,the chemical composition is rich in Si,poor in Na,Al and O;the dawsonite of Wuerxun Depression（The formation of temperature between 78.56~115.02℃） is mainly columnar pin,chemical composition is rich in Na,Al and O,poor in Si.