西湖凹陷平湖地区平湖组沉积相的再认识

The recognition about sedimentary facies in Pinghu formation of Pinghu region.

以断坡控砂为指导,结合层序地层分析,综合应用地震和钻井等资料,对西湖凹陷平湖地区平湖组沉积相进行了系统分析,确定了其主要发育的沉积相。扇沉积主要为洪积扇、近岸水下扇和浊积扇,在断陷期早期、中期发育。三角洲沉积主要为辫状河三角洲、扇三角洲,在断陷期中期、晚期发育。潮坪沉积以改造陆源沉积为主,在断陷期早期、中期发育。建立了砂体沉积模式,明确了平湖组各砂层组沉积相展布规律。

According to stratigraphic sequence analysis and the application of seismic survey and well drilling data,sedimentary facies in Pinghu formation of Pinghu region,Xihu Sag were researched systematically guided by the theory of fault-slope controlling sandbody.Main developed sedimentary facies were known. Fan deposition developed in the earlier and middle fault depression period,including pluvial fan,inshore subsea fan and turbidite fan.The delta deposition developed in the middle and late fault depression period,including braided river delta and fan delta.The tidal flat facies mainly were reconstructed terrigenous deposition,developed in the earlier and middle fault depression period.In addition,the depositional pattern was established and the sedimentary facies distribution of each sand-set in Pinghu formation was recognized.