油气地质与采收率2018，Vol.25Issue(3)：29-35,7.DOI:10.13673/j.cnki.cn37-1359/te.2018.03.004
乍得Bongor盆地北部斜坡带P组沉积特征分析
Study of sedimentary characteristics of the P Formation in the north slope of Bongor Basin, the Republic of Chad
摘要
Abstract
Bongor Basin,located in the south-west of the Republic of Chad,is a Mesozoic-Cenozoic passive rift basin evolved under the influence of shear zone of Central Africa Rift.Bongor Basin was in the beginning of a rift lacustrine basin development and always kept expansion through a continuous transgression progress during the sedimentation of the P Formation,during which terrestrial fan delta-lacustrine deposited.The results of core observation show that the P Formation are characterized by near-provenance,deep-water,coarse-grain,gravity-flow and consecutive transgression sediments.Combined with the indication of well-logging and seismic data,it is determined that fan delta,lacustrine and gravity flow develop in the study area.The fan.delta consists of fan delta front and pre-fan delta sub-facies,and the fan delta front consists of submarine distributary channel,estuary bar,interdistributary and sand sheet.Taking the sub-sag in the north slope of Bongor Basin as an example,it is concluded that two main provenance systems exist through coupling analysis of structure and sedimentation,where delta deposits along the long axis.There are two structure-defined sedimentary modes built along the short axis:fan delta grows in the structure-controlled (fault-connected)zone,while gravity flow grows in the nonstructure-controlled zone.关键词
裂谷盆地/沉积体系/扇三角洲/构造-沉积耦合/Bongor盆地Key words
rift basin/sedimentary system/fan delta/structure-sedimentation coupling/Bongor Basin分类
能源科技引用本文复制引用
方正,季汉成,徐刚,杨轩,杜业波,王佳意..乍得Bongor盆地北部斜坡带P组沉积特征分析[J].油气地质与采收率,2018,25(3):29-35,7.基金项目
中国石油天然气集团公司科学研究与技术开发项目“海外风险勘探领域优选和目标评价”(2016D-4302). （2016D-4302）
