北部湾盆地迈陈凹陷东部物源方向及沉积体系时空演化  

Depositional system evolution and provenance orientation in the eastern Maichen Sag, Beibu Gulf Basin

作　　者：胡斌[1] 张靓[2] 季汉成[2] 郭新安[1] 陈栋[1] 

机构地区：[1]中国石化江苏油田分公司物探技术研究院,南京210046 [2]中国石油大学(北京)地球科学学院,北京102249

出　　处：《岩性油气藏》2014年第4期22-27,35,共7页Lithologic Reservoirs

基　　金：江苏油田局级科技项目"北部湾盆地徐闻探区复杂构造精细解释方法研究及目标评价"(编号:JS12046)资助

摘　　要：在岩心、测井、录井及地震数据分析的基础上,通过物源及沉积相综合研究,探讨了北部湾盆地迈陈凹陷东部涠洲组和流沙港组沉积时期的物源方向及沉积体系的时空演化特征。结果表明:迈陈凹陷东部存在北部流沙港低凸起、东部徐闻凸起和南部临高灯楼凸起3个方向的物源体系,物源体系与盆地结构的差异影响了该区的沉积相类型及时空展布。研究区主要发育三角洲、扇三角洲及湖泊等沉积体系类型。就平面展布特征而言,受迈陈凹陷北部宽缓斜坡地形和物源供给充足的影响,研究区北部三角洲展布范围较广,并且存在"大平原,小前缘"即三角洲平原面积广而前缘面积相对较小的特征;研究区南部和东部由于地形较陡,扇三角洲分布相对局限,但垂向厚度大;湖泊相主要分布在研究区中部主体洼陷区,尤其是深湖—半深湖主要分布于研究区西南部。就垂向演化特征而言,流沙港组沉积时期整体为一个湖侵过程,在流二段沉积时期以发育湖相泥岩为主,而涠洲组则发育各种扇体。Based on the detailed analysis of geological data, seismic data and core data, this paper studied the depositional system evolution features and provenance orientation of Linshagang Formation and Weizhou Formation in the eastern Maichen Sag by the method of provenance orientation analysis and depositional system study. The result shows that there are three provenance orientations in the eastern Maichen Sag, including Liushagang salient in the north, Xuwen salient in the east and Lingao-Denglou salient in the south. Because of the difference of the provenance and basin texture, sedimentary facies and facies distribution of the study area vary from plots to plots. Delta, fan-delta and lake depositional systems can be identified in the study area. Affected by the flat, wide slope and abundant clast supply, delta deposition distributed vastly in the north of the study area, featured by expansive delta plain and locally distributed delta front. Influenced by the abrupt slope, the distribution of fan-delta deposition is relatively limited in the south and east. Lacustrine is mainly distributed in the centre of the study area, especially the deep-half deep lacustrine is mainly distributed in the southwest. For vertical sequence, it shows a Liushagang Formation which is characterized by lacustrine facies mudstone in the Formation, and fans are developed in Weizhou Formation. process of lake transgression second member of Liushagang Formation, and fans are developed in Weizhou Formation.

关 键 词：物源方向 沉积体系 涠洲组 流沙港组 迈陈凹陷 

分 类 号：TE121.32[石油与天然气工程—油气勘探]