苏丹Muglad盆地Fula凹陷白垩纪断陷期沉积模式  

Depositional models in Cretaceous rift stage of Fula sag, Muglad Basin, Sudan

作　　者：吴冬[1,2] 朱筱敏[1,2] 李志[3] 苏永地[3] 刘英辉 张梦瑜[1,2] 宋俭峰[1,2] 刘爱香[3] 陈相亦[1,2] 赵东娜 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室 [2]中国石油大学(北京)地球科学学院 [3]中国石油勘探开发研究院 [4]中国海洋石油上海分公司 [5]壳牌中国勘探与生产有限公司

出　　处：《石油勘探与开发》2015年第3期319-327,共9页Petroleum Exploration and Development

基　　金：国家油气重大专项"岩性地层油气藏沉积体系;储集层形成机理与分布研究"(2011ZX05001-002-005)

摘　　要：基于岩石学、测井相、地震相和砂岩时空分布研究,对苏丹Muglad盆地Fula凹陷白垩纪断陷沉积体系分布进行预测,建立两期断陷沉积模式。Fula凹陷白垩纪发育两期断陷8个三级层序,识别出辫状河三角洲、曲流河三角洲、扇三角洲、湖泊和浊积扇等5种沉积相。Fula凹陷西部陡坡带主要发育扇三角洲—曲流河三角洲相,东部断阶带发育辫状河三角洲—曲流河三角洲相,凹陷中央发育湖泊和浊积扇相。比较两期断陷沉积模式认为:早白垩世Abu Gabra组沉积期断陷活动强烈,沉积体系分布受同沉积断层影响较大,沉积物搬运堆积存在优势通道和有利地区,晚白垩世Darfur群沉积期断陷作用减弱,沉积体系分布受同沉积断层影响较小,沉积物广泛分布。According to the study of petrology, log-phase, seismic facies, and sandstone distribution, the distribution of the Cretaceous rift sedimentary system in Fula sag of the Muglad Basin have been predicted, and the sedimentary models in two rift periods have been established. There developed eight 3^rd-order sequences in the two rift periods in the Cretaceous of Fula sag, which have 5 types of sedimentary facies, namely, braided river delta, meandering river delta, fan delta, lacustrine, and turbidite fan. There mainly developed fan delta-meandering river delta facies in the west steep slope, braided river delta-meandering river delta in the east step-fanlt, and lacustrine and turbidite fan facies in the center of the sag respectively in the Fula sag. It is found from comparison of the depositional models in the two rift periods that, in the depositional stage of Abu Gabra Formation in early Cretaceous, the rifting activity was strong, the distribution of sedimentary system was mainly affected by syn-sedimentary faults, and there were preferential channels and areas of sediments transportation and accumulation; in the depositional stage of Darfur Group in late Cretaceous, the rifting activity weakened, the distribution of sedimentary system was less affected by syn-sedimentary faults, and the sediments were in wide distribution.

关 键 词：断陷湖盆 沉积相 沉积模式 苏丹 Fula凹陷 Muglad盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]