西湖凹陷西部斜坡带宝石组沉积相研究

Sedimentary facies of Baoshi Formation in western slope zone of Xihu Sag

西湖凹陷是我国东海海域天然气勘探的重点区域,随着始新统平湖组和渐新统花港组油气逐步开发利用,中下始新统宝石组逐步成为东海油气勘探的热点领域。目前宝石组受限于埋深大、钻井资料少,对沉积环境及相带认识不够深入。本文综合利用钻井、岩心、古生物及三维地震资料,分析宝石组古气候及古环境,并通过地震相及井-震结合,厘定西部斜坡带宝石组平面沉积展布。结果表明,宝石组整体处于温暖湿润的亚热带气候,整体属浅海沉积环境,在西部斜坡带发育受潮汐影响三角洲、潮坪及局限浅海沉积体系为主,研究成果为西部斜坡带宝石组勘探指出有利方向。

The Xihu Sag is a key area for gas exploration in the East China Sea.With the gradual development and utilization of oil and gas in the Eocene Pinghu and Oligocene Huagang Formations,the Baoshi Formation has gradually become a hot field for oil and gas exploration in the East China Sea.Research on the Baoshi Formation is limited by the lack of drilling data and deep burial depths.Based on the comprehensive utilization of drilling,core,paleontology,and three-dimensional seismic data,the Baoshi Formation is in a warm and humid subtropical climate and belongs to a shallow sea sedimentary environment.Tidal deltas,tidal flats,and limited shallow sea sedimentary systems are mainly developed in the western slope zone.These results indicate a favorable direction for exploration of the Baoshi Formation in the western slope zone.