辽东湾盆地旅大地区古近系层序－岩相古地理编图

Sequence-based lithofacies and paleogeography mapping of Paleogene in Lvda area,Liaodongwan Basin

通过大量岩心和测井资料分析,结合部分地震资料,依据高分辨率层序地层学原理,将辽东湾盆地古近系划分为2个超长期、6个长期、18个中期和数10个短期旋回层序。在综合长期层序界面和结构特征的基础上,选择长期旋回的上升和下降相域为等时地层单元编制层序、岩相古地理图,得出了长期旋回的古地理演化规律为:在LSC2和LSC3时期,以发育浅湖和湖底扇沉积体系为主,LSC4时期以发育三角洲和湖底扇沉积体系为主,到LSC5和LSC6时期以发育三角洲和湖泊沉积体系为主,自下而上形成浅湖→湖底扇→三角洲沉积演化过程和砂体展布规律。从而为有利储集砂体的预测提供了依据。

According to the data of cores, logging and some seismic data, under the guidance of the theory of highresolution sequence stratigraphy, the Paleogene is divided into two super long-term sequence cycles, 6 long-term sequence cycles, 18 middle-term sequence cycles and some dozens of short-term sequence cycles. Based on interfaces and structure characteristics, by selecting the rising and falling base-level phases of each long-term sequence cycle as the isochronous mapping unit, the sequence-based lithofacies and paleogeography maps are drawn. The evolution rule is deduced： during the phase of LSC2 and LSC3, the primary depositional environments are shallow lake and sublacustrine turbidite fan; sublacustrine turbidite fan and delta are developed during the phase of ISC4; and during the phase of ISC5 and LSC6, delta and shallow lake become prevalent. From bottom to top, shallow lake, sublacustrine turbidite fan and delta depositional configuration formed, and the sand body extended, which can provide basis for forecasting reservoir sand body.