松辽盆地扶杨油层(K1q3+4)沉积环境

通过研究取心井段的岩相、岩相组合和垂向沉积层序,可将扶杨油层(K₁q3+4)的沉积环境划分出数种类型:砂质网状化河道、低弯度河道、决口扇、河间湖泊、水进式三角洲和滨浅湖相等。杨大城子油层沉积时期,北部、西部和南部沉积体系的网状化河、低弯度河在盆地东部汇合,发育曲流河。扶余油层开始沉积以后,在盆地西部河流汇水形成湖泊。在扶余油层沉积晚期,湖面迅速扩大,只有南部沉积体系,由于丰富的沉积物供给,发育水进式三角洲沉积,而其余地区,河口砂坝被改造成由粉砂岩和薄互层组成的滨浅湖相。 

SEDIMENTARY ENVIRONMENTS OF FUYANG OIL RESERVOIR (K1q3+4) IN SONGLIAO BASIN

By studing the lithofacies of coring well sections, lithofacies assemblages and vertical sedimentary sequences , several types of sedimentary environments including sandy braided channels, low sinuosity channels , crevasse splays, interstreams lakes , transgressive deltas , shore shallow lakes etc. can be recOgnized in Fuyang oil reservoirs(K₁q3+4).During the sedimentary period of Yangdachengzi oil reservoir, the braided and low sinuosity channels in northern, western and southern sedimentary systems converged in the eastern basin and developed into meandering streams. Along with the sedimentation of Fuyu reservoirs, streams in the western basin began to form lakes. At the late sedimentary stage of Fuyu oil reservoir, lakes quickly extended. Only the sedimentary system in the south developed transgressive delta deposit because of the abundant supplies of sediments. But in other regions, estuarine sandbars were transformed to shore shallow lakes composed of siltstones and thin interbeds.