昌图凹陷层序地层与油气储层预测

SEQUENCE STRATIGRAPHY AND RESERVOIR PREDICTIONOF CHANGTU DEPRESSION

昌图凹陷九佛堂组—阜新组可划分出３个中期基准面旋回：ＭＳＣ１，ＭＳＣ２和ＭＳＣ３。除ＭＳＣ１旋回为一对称旋回外，其它两个旋回均只发育上升半旋回。经井震对比，这３个中期旋回与地震剖面上划分出的ＳＡ，ＳＢ和ＳＣ有很好的对应关系。经分析，ＭＳＣ１中扇三角洲前缘沼泽化的煤层、浅湖相泥岩和ＭＳＣ３中最大洪泛期暗色泥岩是最有利的烃源岩；各旋回中的扇三角洲前缘亚相和水下扇扇中亚相是较好的储集相带。今后的油气勘探中，应将ＭＳＣ３上升半旋回的中上部和ＭＳＣ１上升半旋回作为主要的勘探层系。

The Jiufutang Fuxin Formations could be divided into MSC1, MSC2 and MSC3 medium term base level cycles, among them MSC2 and MSC3 are elevated semi cycles.These three cycles correspond well to S A,S B and S C recorded in seismic sections.Accordimg to well drilling and seismic data,the marsh coal bed in fan delta front and shallow lake mudstone of MSC1 and the flood dark mudstone of MSC3 are most favourable source rocks;fan delta front subfacies and subaqueous medium fan subfacies of every cycle are good reservoir facies.It is suggested that the middle and upper parts of MSC3 and MSC1 elevated semi cycles should be taken as the main exploration sequences.