准噶尔盆地吉木萨尔凹陷中-上二叠统沉积相特征

SEDINENTARY CHRACTERISTICS OF MIDDLE-UPPER PERMIAN IN JIMUSAER SAG OF JUNGGAR BASIN

准噶尔盆地东部吉木萨尔凹陷中-上二叠统由上芨芨槽子群、泉子街组、梧桐沟组组成.凹陷内中-上二叠统经历了低水位域→高水位域→低水位域的变化过程,其有利相带以扇三角洲和三角洲相为主,主要发育于东斜坡区的东北部及东南部以及凹陷南北两侧断裂下盘,在南北局部的乌拉泊组和梧桐沟组还发育浊积扇.油气显示集中于三角洲或扇三角洲相带内(芦草沟组、梧桐沟组),凹陷腹部深湖-半深湖相内的扇三角洲和三角洲沉积区是凹陷内油气的最有利聚集区和保存区.

Middle-Uper Permian in Jimusaer Sag of Junggar Basin Can be divided into Upper-Jijicaozi group, Lucaogou formation and Wutonggou formation. Middle-Uper Permian in Jimusaer Sag underwent a series of system tracts: lowstand system tracts-highstand system tracts-lowstand system tracts. The favorable reservoirs are mainly developed in fan delta and delta which located in north-eastern and south-eastern area as well as boundary fault zone in south and north margin. Turbidite fan of FM Wulabo and FM Wutonggou are also scattered in North and South Margin area. Show of oil and gas mainly concentrated in Fan delta and delta (Lucaogou formation Wutanggou formation), However, the most favorable oil and gas reservoirs are accumulated and preserved in hinterland of sag where delta and fan delta of deep lake-semi-deep lake developed.