陆相断陷湖盆扇三角洲高分辨率层序分析——以保山气田羊邑组2～3段为例

ANALYSIS OF HIGH RESOLUTION SEQUENCE STRATIGRAPHY OF FAN DELTA IN CONTINENTAL LAKE BASIN: TAKING THE 2ND AND THE 3RD MEMBERS OF YANGYI FORMATION IN BAOSHAN GAS FIELD AS EXAMPLES

云南保山盆地是一个典型的陆相断陷盆地，主要沉积中新统南林组和上新统羊邑组地层，其中羊邑组发育扇三角洲前缘亚相的砾岩、砂泥岩组合，为保山气田的产气层段。依据高分辨率层序地层学原理，运用地表露头、岩心、测井和二维地震资料，对羊邑组2～3段进行了详细的高分辨率层序地层学分析。在Ⅳ级、Ⅴ级、Ⅵ级3种不同级别层序界面和相应的湖泛面识别基础上，将羊邑组2～3段地层划分为9个中期、30个短期、64个超短期基准面旋回层序。在此基础上，对高分辨率层序分析结果在地层的等时对比、高分辨率层序地层格架建立、砂体精细对比等方面上的应用进行了研究。

The Baoshan Basin is a typical continental faulted basin dominated by Miocene Nanlin Fm and Pliocene Yangyi Fm. Yangyi Fm contains conglomerate and sand-shale combination of fan delta front subfacies, which are the pay zones of Baoshan gas field. Outcrop, core, logging and 2D seismic data are used to perform detailed high resolution sequence stratigraphy analysis of the 2nd and 3rd members of Yangyi Formation in Baoshan gas field according to the principles of high resolution sequence stratigraphy. Based on identification of sequence boundaries of grade Ⅳ, Ⅴ and Ⅵ and their corresponding lake flood-planes, the 2nd and 3rd members of Yangyi Formation are divided into 9 medium-term, 30 short-term and 64 super-short-term basal level cyclic sequences. Application of these results is studied in respects of isochronous correlation of strata, building of high resolution sequence stratigraphic framework and fine correlation of sandbodies.